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  • 1970-1974  (11,679)
  • 1950-1954  (2,009)
  • Polymer and Materials Science  (12,791)
  • Engineering General  (489)
  • Computational Chemistry and Molecular Modeling  (408)
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Material
Years
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  • 101
    Electronic Resource
    Electronic Resource
    Method of complex molecular orbitals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 799-816 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the spirit of Löwdin's extended HF scheme, an SCF method for the description of the molecular ground state, based on complex molecular orbitals, is developed. As a special case the method of parity mixing in orbitals is formulated. A calculational procedure for solving derived secular equations is described and numerical results, obtained in the minimal basis set, are reported for the N2 and CO molecule. Resulting ground state energies are close to the energies of the CI calculations with the same set of orbitals.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080515
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  • 102
    Electronic Resource
    Electronic Resource
    Electronic correlation studies. II. Self-correlated field method. Application to ground state and first 1P, 3P excited states of two-electron atomic systemsAbstracted from part of a thesis submitted by R. Lissillour to the University of Rennes, 1973. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 825-838 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An antisymmetric pair function can be built upon two kinds of monoelectronic functions, the former ones being correlated local functions and the second ones nonlocal functions taking external effects into account. This function, brought into the generalised product function procedure by means of the density matrix formulation, makes possible the study of correlation within N-electronic systems. The results of a first application of this method to the fundamental and to 1P and 3P excited states of two-electron systems are given.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080602
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  • 103
    Electronic Resource
    Electronic Resource
    Configuration interaction calculations on the nitrogen molecule (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 61-72 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A contracted Gaussian basis set capable of describing about 63% of the correlation energy of N2 has been used in a detailed configuration-interaction calculation. Second-order perturbation theory overestimated the correlation energy by 23-50% depending on how H0 was chosen. Pair-pair interaction affects the correlation energy by about 20% while quadruple excitations have an 8% effect.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080106
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  • 104
    Electronic Resource
    Electronic Resource
    Matrix elements for spin-adapted configurations (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 83-89 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that the turn-over rule which is used to simplify matrix elements between spin-projected Slater determinants may also be used to simplify formation of matrix elements between any orthonormal set of spin-coupled Slater determinants. The coefficients for the spin-coupling may then be chosen freely to reduce the number of important configurations in the secular equation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080109
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  • 105
    Electronic Resource
    Electronic Resource
    Application of the distinguishable electron method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 137-150 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to make a better assessment of the distinguishable electron method developed by Kirtman and co-workers, we have applied the method to some two-electron atoms and to H2 and LiH. Our results lend support to the contention held by Kirtman and co-workers that the distinguishable electron method is a practical way of calculating reasonably accurate physical properties.
    Additional Material: 10 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080114
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  • 106
    Electronic Resource
    Electronic Resource
    Waller-Hartree spin-free method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 523-537 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this paper we show that with the equivalent transformation Pr = (-1)P(Pσ)-1 the spin function dependent methods such as Slater's method without group theory or Goddard's method with group theory differ only in different antisymmetric requirements from the present Waller-Hartree spin function free method. There exists a one-to-one correspondence between Slater's determinantal wave function and the Waller-Hartree double determinantal wave function. Explicit expressions for the S2 operator, Löwdin's spin projector, matric basis and several different forms of spin-projected functions are given for the Waller-Hartree formalism. The results are compared with other methods including those of Slater, Matsen, Gallup, Goddard and Segal. The differences are quite significant. New spin operators are worked out using creation-destruction operators. A knowledge of group theory is not required in this Waller-Hartree method. We have also shown that the Waller-Hartree method is more convenient than Slater's method with spin functions especially in the evaluation of the functional HΨ/Ψ. The advantages and disadvantages in the use of a linear combination of N! Hartree products and linear combinations of all possible double determinants are discussed. In addition, a formula for the calculation of the Sanibel coefficients C(S, M, i) is obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080404
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  • 107
    Electronic Resource
    Electronic Resource
    Nonbonded interactions in membrane active cyclic biopolymers. I. Valinomycin-potassium ion complexThe results of this paper were presented in summarized form at the Edward U. Condon International Symposium on Atomic, Molecular and Solid State Theory and Quantum Biology at Sanibel Island, Florida, U.S.A., January 1973. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 565-583 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method for quantitative comparison of various conformers of cyclic macromolecules in terms of nonbonded interaction energy terms is proposed. The first step in the procedure is an analytical evaluation of a set of Cartesian atomic coordinates consistent with the ring closure condition and prescribed values for internal parameters. A variant of the same technique enables different conformations of the macromolecule to be generated. Nonbonded interactions of the electrostatic, polarization and dispersion type and van der Waals repulsion are calculated using the generated coordinates, empirical bond polarizability data and results of simple molecular orbital calculations. An application of the proposed techniques to the closed symmetric conformation of valinomycin indicates that the macromolecule by itself is somewhat constrained in this state but that its affinity for a potassium ion is very strong - much stronger than the hydration energy of the latter.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080408
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  • 108
    Electronic Resource
    Electronic Resource
    Intermediate problems for eigenvalues (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 623-625 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080412
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  • 109
    Electronic Resource
    Electronic Resource
    Ab initio calculations on urea (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 857-892 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Multiconfiguration wave functions constructed from contracted Gaussian-lobe functions have been found for the ground and valence-excited states of urea. ICSCF molecular orbitals of the excited states were used as the parent configurations for the CI calculations except for the 1A1(π → π*) state. The 1A1(π → π*) state used as its parent configuration an orthogonal linear combination of natural orbitals obtained from the second root of a three-configuration SCF calculation. The lowest excited states are predicted to be the n π → π* and π → π* triplet states. The lowest singlet state is predicted to be the n π → π* state with an energy in good agreement with the one known UV band at 7.2 eV. The π → π* singlet state is predicted to be about 1.9 eV higher, contrary to several previous assignments which assumed the lowest band was a π → π* amide resonance band. The predicted ionization energy of 9.0 eV makes this and higher states autoionizing.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080604
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  • 110
    Electronic Resource
    Electronic Resource
    Spin-orbit interaction in polyatomic molecules: Ab initio computations with Gaussian orbitals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 941-950 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Standard sets of Gaussian atomic orbitals (STO-3G, STO-4.31G) are used to evaluate spin-orbit coupling constants in linear molecules (CO2+, NNN) and spin-orbit effects on singlet-triplet transition intensities in formaldehyde. All spin-other orbit effects have been included. In all cases spin-other orbit interactions form a large fraction of the matrix elements. Simple formulae to evaluate spin-orbit one- and two-electron integrals over atomic orbitals are presented. Standard molecular integral programs can be used for the computation of spin-orbit integrals.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080609
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  • 111
    Electronic Resource
    Electronic Resource
    Error analysis of variationally optimized upper- and lower-bound wave functions for H2+Work supported in part by the National Research Council of Canada. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 971-980 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wave functions which are a linear combination of H2+-type elliptical orbitals are optimized to provide either an upper bound or a lower bound to the H2+ ground state. For the latter, Temple's formula is used. Three criteria are considered to determine the relative accuracy of these wave functions: (i) energy (calculated versus exact eigenvalue); (ii) average error; and (iii) local energy. Although the lower-bound optimized wave functions obtained are the most accurate available for H2+ from approximate wave functions, they are still inferior to the corresponding upper-bound wave functions by criteria (i) and (ii). In particular, using criterion (ii), it is shown numerically that the upper-bound functions are “correct to second order,” while the lower-bound functions are almost, but not quite, “correct to second order.” Despite this, the local energy analysis, criterion (iii), reveals that the lower-bound wave functions can be more accurate than the upper-bound functions in some regions of space, and hence give more accurate values for physical properties sensitive to these regions. Examples considered are the dipole-dipole and Fermi contact interactions.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080611
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  • 112
    Electronic Resource
    Electronic Resource
    Variation of the polarizability of the hydrogen molecule ion and the hydrogen molecule with internuclear separation (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 91-95 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The variation of the polarizability of H2+ and H2 with internuclear separation R = 1.6 - R = 2.4 a.u. for H2+ and R = 1.0 - R = 2.0 a.u. for H2 is determined using a variational method suggested by Das and Bersohn. From these data, values of 〈α〉0,J for which nuclear motion due to zero point vibration and centrifugal stretching is taken into account, are calculated at 300°K. The relative percent increases of the motion averaged values compared to the equilibrium values are as follows: 10.50% for H2+ and 6.52% for H2.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080110
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  • 113
    Electronic Resource
    Electronic Resource
    Floating one-center perturbation treatments for H2+-like molecules based on screened hydrogen atom or molecular puff unperturbed problems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 119-136 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various floating one-center perturbation schemes are developed for H2+-like molecules. Previous work for the ‘1s’ hydrogen atom approach is extended through third order in the energy. In the molecular puff approach an exact ‘closed form’ solution is obtained for the zeroth-order problem, which corresponds to a double layer molecular puff. Semianalytical results for the first-order correction to the floating molecular puff wave function and for the energy through third order are developed which offer a convenient alternative to previous approaches. Explicit calculations for ground state H2+ show that for R 〉 3aO the ‘1s’ and the more complicated ‘puff’ treatments are equivalent and that neither the ‘1s’nor the molecular puff function is an adequate zeroth-order wave function for the important intermediate values of R. The usefulness of some of these methods in a variety of problems, where one-center zeroth-order wave functions do appear to be adequate, is discussed briefly.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080113
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  • 114
    Electronic Resource
    Electronic Resource
    Accurate analytical self-consistent field wave functions for Tm2+ and Tm3+ (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 73-78 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The analytical expansion self-consistent field method was employed to perform ab initio calculations for the ground states of the rare-earth ions, Tm2+, 4f13, 2F, and Tm3+, 4f12, 3H, (Z = 69). In each case the total number of basis functions used in the analytical expansions was 29, distributed as follows: 10, 8, 5, and 6, for the symmetries s, p, d, and f, respectively. All of the orbital exponents of the basis functions were optimized repeatedly, to the extent of the single-precision computer representation. Values of 〈rn〉 for the 4f orbital of both ions are also presented, for the convenience of experimentalists.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080107
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  • 115
    Electronic Resource
    Electronic Resource
    Coupled Hartree Fock calculation of static dipole polarizabilities and shielding factors of open shell systems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 97-105 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Static dipole polarizabilities and shielding factors for the 2p open shell atomic systems are presented using coupled Hartree Fock theory in the framework of the Roothaan formalism. Calculations have been performed for the ground as well as for some valence excited states. A variational approach has been adopted for the determination of the first-order perturbed functions. The results are compared with those obtained from the correlated calculations and other techniques. The shielding factor values are in excellent agreement with the theoretical N/Z ratio.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080111
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  • 116
    Electronic Resource
    Electronic Resource
    Extended Hartree-Fock self-consistent field with some results for berylliumlike atomic systems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 839-855 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The general methods of deriving the extended Hartree-Fock equations are described. The rules for going over from the energy expression in the ordinary method of calculation to that in an extended one are reformulated and illustrated. The extended Hartree - Fock equations for berylliumlike atomic systems based on the use of nonorthogonal radial orbitals are given and solved. The numerical values of overlap integrals and total energies are given and discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080603
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  • 117
    Electronic Resource
    Electronic Resource
    Dynamic polarizability of helium: A random phase approximation calculation (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 901-913 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The random phase approximation (RPA) or time-dependent Hartree-Fock approximation (TDHF) is reconsidered for the calculation of the dynamic polarizability for atoms. An integral equation which admits a simple numerical treatment is established. The asymptotic approximation for the electron propagator is tested for its applicability by means of comparisons with earlier results.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080606
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  • 118
    Electronic Resource
    Electronic Resource
    Book Reviews (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 995-995 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080613
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  • 119
    Electronic Resource
    Electronic Resource
    Molecular integrals over generalized gaussian basis sets (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 179-191 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is given for obtaining the common molecular integrals over generalized gaussian functions: \documentclass{article}\pagestyle{empty}\begin{document}$$ \chi_i = x^{\lambda_i}_i \exp \big\{ - \big(\alpha_i x^2_i + \alpha^{\prime}_i x^{\prime 2}_i + \alpha^{\prime\prime}_i x^{\prime\prime 2}_i\big)\big\} $$\end{document}The present algorithms are expected to be more efficient than those given in earlier work by the same author.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080205
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  • 120
    Electronic Resource
    Electronic Resource
    On the need of precision in the calculation of the LCAO density matrix of polymers (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 201-208 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this paper, we point out how the precision of the LCAO density matrix elements of polymers may affect the computed properties. We propose to use a more adapted approach in order to evaluate these quantities.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080207
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  • 121
    Electronic Resource
    Electronic Resource
    The Coulomb hole in the 23S state of the helium isoelectronic sequence (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 255-261 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pair distribution functions evaluated for the 23S state of the helium isoelectronic sequence from the Hart and Herzberg correlated wave functions and those corresponding to the Hartree-Fock approximation are used to determine the shape of the corresponding Coulomb holes. As a consequence of a discontinuity in the Hartree-Fock solution between He and Li+, the Coulomb hole has a different shape for He than for Li+ and the other isoelectronic ions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080212
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  • 122
    Electronic Resource
    Electronic Resource
    Oscillator and hydrogenic matrix elements by operator algebra (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 585-604 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Occupation number representation of the two-dimensional harmonic oscillator and some operator formulae are used in a simple algebraic derivation of complicated integrals. The calculation of full oscillator- and radial integrals of r̂w and exp (\documentclass{article}\pagestyle{empty}\begin{document}$ (iw\hat{\varphi})$\end{document}), where w is an arbitrary positive or negative integer, are performed by an integral transform, leading to a generalized Gauss matrix element. Thus it is possible, because of the back transformation, to derive from one generalized Gauss matrix element all matrix elements which are permitted by the selection rules. Some integrals of r̂w and exp (\documentclass{article}\pagestyle{empty}\begin{document}$ (iw\hat{\varphi})$\end{document}), Laguerre polynomials, and Bessel functions are completely new. For the already known integrals, the mathematical labour is considerably reduced. The relation between the two-dimensional oscillator and the hydrogen atom and their angular momentum properties are discussed. A survey on the various methods applied to the oscillator problem, from complex integration to noncompact Lie groups, and a comprehensive bibliography on this important spectroscopic field are given.
    Additional Material: 604 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080409
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  • 123
    Electronic Resource
    Electronic Resource
    Electron correlation study for two-electron atoms by a simple correlated wave function (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 755-764 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The difference in the electron correlation between H- and other two-electron atoms is clarified by the introduction of the r12 term in the wave function. By using the expansion of r12, a certain modification of the usual electron correlation factor 1 + Cr12 is introduced and its effectiveness is examined. Calculations are carried out for the ground state and the three lowest excited states (23S, 23P and 21P). The peculiar electron correlation in the ground state of H- is shown by looking at the Coulomb hole for closed- and open-shelf models in comparison with those for other two-electron atoms.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080510
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  • 124
    Electronic Resource
    Electronic Resource
    Virtual orbital transformation prior to configuration interaction with localized orbitals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 777-782 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A virtual orbital transformation is proposed involving pairing of localized occupied orbitals with virtual orbitals. The virtual orbitals are transformed so that each virtual orbital is as “close” as possible to its occupied counterpart, where closeness is the inverse of the particular definition of localization. The appropriate transformation is derived for the special case of Foster-Boys localization, and an illustrative CNDO/2 calculation on HNO is presented. INDO CI results on the series N2, CO, BF indicate that use of this transformation may reduce the number of energetically significant configurations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080512
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  • 125
    Electronic Resource
    Electronic Resource
    Molecular orbitals of nitrogen at small internuclear distances (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 817-821 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080516
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  • 126
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    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080601
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  • 127
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    Perturbative ab initio calculations of intermolecular energies. I. Method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 1-15 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Starting from a knowledge of approximate wave functions of the isolated molecules (or atoms) A and B, a method is proposed to build up a zeroth-order ground state and excited configurations for the complex AB in which the molecular orbitals keep their local significance. The standard Rayleigh-Schrödinger perturbation in this basis provides a decomposition of the zeroth-order interaction energy as a sum of the electrostatic and repulsion energy. In the second order, it is possible to identify the classical dispersion and polarization forces (modified by a term of order S2) and two additional contributions which are linked to the exchange possibility. The intramolecular correlation component is taken into account and compared with the correlation on the isolated molecules. It is moreover suggested that since we work in a rather limited basis set, the perturbed energy of AB must be compared with the unperturbed energies of A and B calculated in a basis including the vacant orbitals on their respective partner. Finally a possibility for going beyond the second order is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080102
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  • 128
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    Matrix formulation of the generalized Hartree-Fock methods (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 45-60 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Spin-projected one-particle density and spin density matrices are presented as polynomials of suitable unprojected quantities with generalized Sasaki-Ohno coefficients. Thus an explicit form of Harriman's theorems is given. For the two-particle spatial density matrix an expansion in direct products of powers of unprojected residual electron and spin density matrices is given. For these basic matrices of the scheme the variational spin-extended equations are formulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080105
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  • 129
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    Symmetry adaptation and the relation between the spin-free and space-spin formulations of electronic structure (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 223-233 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An information-theoretic degree of symmetry adaptation of a ket with respect to a given group is introduced. Then the general equivalence between spin-free electronic kets and antisymmetrized space-spin kets is obtained so long as our attention is restricted to spin-independent observables. It is noted that there are spin-free kets for which there exists no single antisymmetrized space-spin ket giving all the same expectation values; the converse is also noted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080209
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  • 130
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    Transformation properties of many-electron wave functions with special attention to the relation between pair-correlated DODS and configuration interaction (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 715-732 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is presented that leads to a simple derivation of the explicit relation between pair-correlated DODS schemes (e.g., the alternant molecular orbital method and the extended valence bond method) and configuration interaction.This result is based on a reduction formula for the representations of the general linear group, GL(m), carried by the N-electron function space. Generally, this paper deals with the effect of “partitioned” orbital transformations on states with “local” permutation symmetry.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080507
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  • 131
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    Ab initio calculations on porphin (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 915-924 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio SCF calculations are reported for the porphin molecule. The positions of the central protons have been optimized, and the equilibrium geometry is found to be a linear NH ⃛ HN arrangement. The NH vibrational frequencies have been computed and are compared to experimentally measured quantities. Several low ionized states have also been studied in separate spin-restricted SCF calculations. The lowest state is found to have B1u symmetry with an ionization potential of 8.0 eV.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080607
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  • 132
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    Basis dependence of wave functions of the ground state and low-lying excited states of planar formaldehydeThis is a part of a thesis for the Ph.D degree conferred by the Hokkaido University. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 981-993 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By the use of three bases containing 3p STO's possessing different diffuseness, the electronic structure of several excited states (valence- and Rydberg-type) of planar formaldehyde is investigated by limited CI calculations. The spatial extension of the valence-type state is independent of the bases, whereas a diffuse orbital is important in describing the Rydberg-type state. The natural orbital analysis shows that the Rydberg-type states can be described as an outer electron plus an electronic cloud representing the ionized state to which the Rydberg states converge.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080612
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  • 133
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    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080101
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  • 134
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    Perturbative ab initio calculations of intermolecular energies. III. The water dimer (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 29-43 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction energy between two water molecules A and B is calculated by the method described in Paper I [1], previously applied for the interaction between two helium atoms (Paper II) [2]. This interaction energy is obtained as the difference between the energies of the complex (A + B) and the monomers (A) and (B), obtained by a perturbation method. The results obtained with the perturbation developed up to the second order in a minimal atomic basis set are decomposed into classical contributions and contributions linked to the exchange possibility. Charge transfer contributions are important and the localized character of the hydrogen bond is examined. It is pointed out that the definition of the set of excited configurations for the calculation of the energies of the isolated monomers is important, especially when one tries to use a small atomic basis set. A similar effect in SCF-type calculations is evaluated. The contribution of higher orders is evaluated by the CIPSI method.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080104
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  • 135
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    Alternative equivalent icosahedral irreducible tensors (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 153-161 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some sets of icosahedral irreducible tensors can only be defined with respect to one of two seemingly equivalent choices of axes. The problem is explained and the cases when such an alternative choice may cause mixing of sets belonging to different irreducible representations are determined. It is found that the amount of mixing is a property of the spherical basis sets and is independent of the rank and of the permutation symmetry of the tensorial sets. It is further found that certain operators which change the handedness of the coordinate axes can similarly affect these sets, notwithstanding the centrosymmetry of the icosahedron.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080202
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  • 136
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    Structure de l'ion fluoronium FH2+ et chemin de la protonation du fluorure d'hydrogeneTravail préasentéea à l'occasion du Premier congrès international de chimie quantique (4-10 juillet 1973, Menton, France) (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 193-200 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structure of the ion FH2+ is investigated on the basis of semiempirical (INDO) and nonempirical (extended gaussian basis set) calculations. In agreement with experiment, both methods predict that, when going from FH to FH2+, there is a lengthening of the F—H bond; also in agreement with infrared analysis, the calculations indicate a bent structure for the fluoronium ion (valence angle at about 120°). The analysis of the FH protonation path reveals the existence of a potential barrier which is exclusively produced by solvation effects; the dependence of the proton affinity of FH on the dielectric constant of the reaction medium is also discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080206
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  • 137
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    Comments on kets not strongly symmetry adapted (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 235-245 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various instances in which weakly or nonsymmetry-adapted kets may arise in the description of electronic systems are discussed. These cases include some types of selfconsistent field kets, exchange perturbation kets, and multistate kets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080210
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  • 138
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    Symmetries of n-electron wave functions under various spatial groups (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 267-291 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new method is used to arrive at Kotani's formula (vide infra) for the character of the representation of the group of spatial symmetry provided by functions which are eigenfunctions of the total spin operator. An alternative form involving determinants of the symmetric functions is also given. The results are applied to some cases which were untreated before and have particular interest in valence-bond calculations. The problem of the construction of bases functions of the given symmetry is also discussed, and a solution with a wide range of applicability is given.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080214
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  • 139
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    A variational perturbation treatment of the hydrogen molecular ion using the green function method on the united atom (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 319-333 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We calculated the second-order perturbed energy and the first-order perturbed wave function of the hydrogen molecular ion by the Green function method based on a united atom with effective nuclear charge, Z. Since the perturbation is given by (Z/r)  -  (1/rA)  -  (1/rB), its magnitude depends on the parameter Z. We obtain an analytical expression for the second-order perturbed energy as a function of Z and the internuclear distance R. We discuss a variety of methods to determine the best values for Z and to derive the potential energy curve and the force constant for H2+; these methods vary in the accuracy of their results.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080302
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  • 140
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    The self-consistent symmetrized OPW method with an application to crystalline selenium (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 395-422 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A review of the nonrelativistic self-consistent symmertrized orthogonalized-plane-wave (SCSOPW) method used for determining electronic energy bands in periodic solids is given. Working equations based on the full use of group theory at all stages are presented for elemental crystals. As an example the method is applied to the trigonal selenium crystal.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080307
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  • 141
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    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080401
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  • 142
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    Electronic Resource
    Brillouin-Wigner perturbation theory and the generalized eigenvalue equation (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 491-498 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A Brillouin-Wigner perturbation expansion is derived for the generalized eigenvalue equation (F0 + F1)Ψ = μAΨ. The theory is applied through second order to calculate the ground-state energies of the helium atom and the hydrogen molecular ion. The results are compared with the corresponding Rayleigh-Schrödinger expansion. For the examples we consider, the Brillouin-Wigner results through second order are generally superior to the Rayleigh-Schrödinger ones.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080402
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  • 143
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    Electronic Resource
    A technique for orbital exponent optimization in ab initio HF—SCF—LCAO—MO calculations (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 547-557 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A technique for Slater orbital exponent optimization in an HF—SCF—LCAO—MO calculation is proposed in which orbital exponent variation is incorporated into the SCF scheme. This is accomplished by rewriting Slater's rules so that the shielding terms depend on the molecular charge distribution through the elements of the population matrix. The SCF scheme then includes a calculation of a new set of orbital exponents from the coefficients of self-consistent molecular orbitals obtained from the previous set of exponents. The process is iterated until the energy attains its lowest value.The technique is illustrated by minimal basis calculations on LiH, BH, and HF. Near optimization is obtained with considerably less effort than is necessary for other reported techniques. Aside from interesting properties, the technique can be important for extended basis calculations where exponent optimization is a difficult task.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080406
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  • 144
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    Electronic Resource
    Gradient of the general energy expression (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 619-621 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080411
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  • 145
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    Announcement (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 633-633 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080414
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  • 146
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    Simplification of Kronecker products for the representations of point groups having only one n-fold axis with n ≧ 3 (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 627-632 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080413
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  • 147
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    Electronic Resource
    Hammerstein integral equivalent of Riccati's equation (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 677-692 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A transformation exists which allows the general Riccati equation \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c}{{dy\left( r \right)} \mathord{\left/ {\vphantom {{dy\left( r \right)} {dr = A\left( r \right) + }}} \right. \kern-\nulldelimiterspace} {dr = A\left( r \right) + }}B\left( r \right)y\left( r \right) + C\left( r \right)y\left( r \right)^2 \hfill & 0\leqq r 〈 b \end{array}$$\end{document} to be written in a simpler form: \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$ d\beta (r)/dr\, = \,P(r)\, + \,R(r)\beta (r)^2 \quad 0\buildrel{〈}\over{=} r 〈 b $$\end{document} The transformed equation has the equivalent nonlinear Hammerstein integral equation \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c}\beta (r) = K\int_{r^{\prime} = 0}^b P(r^{\prime}) N(r, r^{\prime})dr^{\prime} \quad 0\buildrel{〈}\over{=} r 〈 b \end{array}$$\end{document} if the kernel N(r, r′) satisfies three conditions: \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {({\rm i})} & {\{ d/dr - R(r)\beta (r)\} N(r,r)} \\ \end{array}\, = \,\delta (r,r)/K $$\end{document} and \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {({\rm ii})} & {\{ d/dr'\, + \,R(r')\beta (r')\} N(r,r')} \\ \end{array}\, = \, - \delta (r,r')/K $$\end{document} and \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {({\rm iii})} & {{\rm [}\beta (r')N(r,r'){\rm ]}_{r' = 0}^b } \\ \end{array} = 0 $$\end{document}A solution of the nonlinear integral equation is devised by repeatedly integrating the Hammerstein equation. During this procedure the kernel generates an equation that contains only coefficients of β(r)0 and β(r)1. As a result, after truncating at the end of the nth cycle, it is a simple matter to write down a Padé-type approximation: all coefficients in this approximation are capable of being evaluated in terms of simple algebraic formulations of P(r), R(r), and integrals over P(r).The zeroes of the denominator of the Padé-type approximation define the points where singularities occur in β(r).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080504
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  • 148
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    Equivalence-restricted open-shell SCF theory (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 707-714 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is presented for generating open-shell equivalence-restricted SCF orbitals in high-symmetry situations using Roothaan-Hartree-Fock programs which are adapted for lower symmetry.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080506
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  • 149
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    Half-projected and projected Hartree-Fock calculations for singlet ground states. II. Lithium hydride (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 733-743 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The half-projected Hartree-Fock function (HPHF) for singlet states is defined as a linear combination of two Slater determinants which contains only spin eigenstates with even spin quantum numbers. The possible uses of such an approach for determining molecular properties are investigated computing the potential energy curve, binding energy, force constant, and dipole moment variation corresponding to the lithium hydride ground state. Full projected and restricted Hartree-Fock calculations (PHF and RHF) are performed simultaneously for comparison purposes. It is found that the HPHF model yields very satisfactory results, very close to those of the PHF scheme. Both models predict properly the molecular behavior as a function of nuclear separation, whereas the RHF one fails. A discussion is given in terms of configuration equivalents. It is concluded that the HPHF scheme seems to be useful for determining molecular properties specially in the case of large systems in which the more sophisticated methods are unmanageable.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080508
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  • 150
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    A general ab initio molecular multi-configuration self-consistent field algorithm (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 783-788 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ab initio multiconfiguration self-consistent-field (MC SCF) techniques and computer programs of Basch [1, 2] and the ab initio configuration interaction (CI) techniques and programs of Whitten and Hackmeyer [3] have been combined and generalized to form a general technique and program to yield optimized ab initio MC SCF wavefunctions for any set of Slater determinants. The Slater determinants are read in as input data to the program along with the spin parity that is being considered (optional) and the program successively does the CI calculation and one iteration of the SCF calculation, constructing the proper Fock-Hamiltonians by examining the set of Slater determinants and their CI coefficients. The Fock-Hamiltonian matrices are calculated and diagonalized in succession, a single two-dimensional array being used to store these matrices. The basis function integrals are read from a tape only once during each MC SCF iteration (one MC SCF iteration = a CI calculation followed by one iteration of the SCF calculation).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080513
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  • 151
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    Vinyl polymerization by metal complexes, 11Part 10, cf.1.. Formation of polyvinylamine-copper(II) chelatesDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 83-93 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Um den Mechanismus der Katalyse der Polyvinylamin-Kupfer(II)-Chelate bei der Auslösung der Vinylpolymerisation zu klären, wurden die Stabilitätskonstanten dieser Chelate durch Anwendung einer modifizierten BJERRUMschen Methode gemessen, und die Konzentration der chemischen Spezies wurde auf Grund der Chelattheorie abgeschätzt. Anhand dieser Ergebnisse wurde die Aktivität der Polyvinylamin-Kupfer(II)-Chelate bei der Polymerisation von Acrylnitril und von Methylmethacrylat bei verschiedenen pH-Werten diskutiert.
    Notes: In order to clarify the mechanism of catalysis of polyvinylamine-copper(II) chelates on the initiation of vinyl polymerizations, stability constants of these chelates were measured by applying a modification of BJERRUM'S method, and each concentration of the chemical species was estimated on the basis of the chelate theory. From these results, the activity of the polyvinylamine-copper(II) chelates for the polymerization of acrylonitrile and methyl methacrylate at different pH values was discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750110
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  • 152
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    Synthesis of poly[4(5)-vinylimidazole-co-γ-vinyl-γ-butyro-lactone] and its catalytic activity in ester hydrolysisDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 119-124 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Copolymerisation von 4(5)-Vinylimidazol mit γ-Vinyl-γ-butyrolacton wurde in Gegenwart von 2,2′-Azoisobutyronitril oder Benzoylperoxid durchgeführt. Die Initiatoren üben keinen Einfluß auf die Copolymerisationsparameter aus. Diese werden auch von Methanol als Lösungsmittel nicht beeinflußt. Die Copolymerisationsparameter wurden zu r1 = 20,0 ± 0,8 und r2 = 0,030 ± 0,002 bestimmt.Die katalytische Aktivität des Copolymers bei der Hydrolyse von p-Nitrophenylacetat (4) und von 3-Acetoxy-N,N,N-trimethylaniliniumjodid (5) bei pH = 8,0 war über doppelt so groß wie die eines statistischen Terpolymers mit Imidazol-, Carbonsäure- und Hydroxyl-Gruppen.
    Notes: Copolymerizations of 4(5)-vinylimidazole (1) and γ-vinyl-γ-butyrolactone (2) initiated by 2,2′-azoisobutyronitrile or benzoyl peroxide were carried out. The initiators did not affect the radical reactivity ratio (r). In addition, the reactivity ratio was not influenced by methanol as solvent. The following ratios were obtained r1 = 20,0 ± 0,8 and r2 = 0,030 ± 0,002.The catalytic activity of the copolymers in the hydrolyses of p-nitrophenyl acetate (4) and 3-acetoxy-N,N,N-trimethylanilinium iodide (5) at pH = 8,0 was found to be more than twice as high as that of a random terpolymer containing imidazole, carboxylic acid, and hydroxy moieties.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750114
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  • 153
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    Influence of the structure of cobalt(III)-poly(4-vinylpyridine) complexes on the electron-transfer reactionDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 171-178 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Kobalt(III)-Komplexe, die einen Polymer-Liganden enthalten, cis-[Co(en)2PVPCl]Cl2, cis-[Co(trien)PVPCl]Cl2, cis-[Co(en)2PVPBr]Br2, cis-[Co(en)2PVPN3]Cl2 und cis-[Co(en)2-QPVPCl]Cl2 (PVP = Polyvinylpyridin, QPVP = teilweise quaterniertes PVP), wurden dargestellt, und ihre Reduktion mit Ferrosulfat wurde untersucht. Es wurde gezeigt, daß die Komplexbildung mit QPVP durch sterische Faktoren beeinflußt wird, wie durch den Polymerisationsgrad des Polymer-Liganden und die Raumerfüllung der Quaternierungsmittel. Die Quaternierung des Polymer-Liganden selbst zeigte jedoch nur einen geringen sterischen Einfluß auf die Reduktionskinetik. Für die verschiedenen Brückenliganden (X) ergab sich folgende Reihe in bezug auf die Reduktionsgeschwindigkeit von cis-[Co(en)2PVPX]2+:N3 〉 Cl 〉 Br. Die Reduktionsgeschwindigkeit von cis-[Co(en)2PVPCl]2+ ist größer als die von cis-[Co(trien)PVPCl]2+. Die Einflüsse der Brücken- und Nichtbrückenliganden auf die Reduktion sind ähnlich für die Polymer-Komplexe und die monomeren Analoga.
    Notes: Cobalt(III)-complexes having a polymeric ligand, cis-[Co(en)2PVPCl]Cl2, cis-[Co(trien)-PVPCl]Cl2, cis-[Co(en)2PVPBr]Br2, cis-[Co(en)2PVPN3]Cl2 and cis-[Co(en)2QPVPCl]Cl2 (where PVP = poly(4-vinylpyridine) and QPVP = partially quarternized PVP) were prepared and their reduction with ferrous sulfate was studied. Complex formation with QPVP was shown to be affected by steric factors such as the degree of polymerization and the bulkiness of the quaternizing agents, but the quarternization showed only a small steric influence on the reduction kinetics. The order of the reduction rate of cis-[Co(en)2PVPX]2+ with respect to the bridging ligand X is N3 〉 Cl 〉 Br, and the reduction rate of cis-[Co(en)2PVPCl]2+ is higher than that of cis-[Co(trien)PVPCl]2+. The effects of bridging and non-bridging ligands in the reduction of polymer complexes were the same as those for the monomeric analogues.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750118
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  • 154
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    Thermodynamic studies based on corresponding states theory for solutions of polystyrene in ethyl methyl ketoneDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 197-208 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die FLORYsche Theorie über das Prinzip der übereinstimmenden Zustände für Polymerlösungen wurde geprüft, indem die theoretisch berechneten Parameter mit experimentellen Ergebnissen verglichen wurden. Der osmotische Druck des Systems Polystyrol/Äthylmethylketon wurde für Polymerkonzentrationen zwischen 10 und 30% bei 10 bis 55°C gemessen. Unter Verwendung der Parameter X12 und Q12, die den erhaltenen Daten am besten entsprachen, wurden die berechneten Parameter mit den experimentellen Ergebnissen verglichen. Der Entropie-Parameter ψ1 sowie der Enthalpie-Parameter χH, 1 waren negativ und nahmen mit steigender Temperatur ab. Mit Hilfe der anpassungsfähigen Parameter X12 und Q12 gibt die FLORYsche Theorie die thermodynamischen Größen ziemlich gut wieder, obwohl eine geringe Abweichung von den experimentellen Ergebnissen zu bestehen scheint. Die SHULTZ-FLORYsche Methode zur Bestimmung der Theta;-Temperatur wurde auf der Grundlage dieser Theorie diskutiert.
    Notes: The polymer solution theory on the corresponding state principle developed by FLORY was examined by comparing the thermodynamic parameters calculated theoretically with experimental results. The osmotic pressure of the polystyrene/ethyl methyl ketone system was determined for solutions of polymer concentrations 10 to 30% at 10 to 55°C. Using X12 and Q12 parameters best fitting to these data, the calculated parameters were compared with experimental results. Both the entropy parameter ψ1 and enthalpy parameter χH, 1 were negative and decreased with increasing temperature. FLORY'S theory elucidates appreciably well the thermodynamic quantities with the use of the adjustable parameters X12 and Q12, but there seems to remain still some disagreement with experimental results. SHULTZ-FLORY'S method for determining the Θ-temperature was discussed based on this theory.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750121
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  • 155
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    Crystallization of polypeptides in the course of polymerization, 5Part 4, cf.5.. Effect of the steric hindrance on the crystal growth by the side chainsDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 283-299 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurde der Einfluß der sterischen Hinderung durch Polypeptid-Seitenketten auf den Wachstumsmechanismus von Polypeptidkristallen während der Polymerisation untersucht. Dabei wurden von uns Untersuchungen der Kinetik der heterogenen Polymerisation von L-Valin-LEUCHS-Anhydrid (NCA), L-Isoleucin-NCA und L-Leucin-NCA mit Butylamin als Initiator in Acetonitril und der Strukturen sowie der Morphologie der gebildeten Polymere durchgeführt. In den Anfangsstadien der Polymerisation bildeten sich Oligomere, die in dünnen, bandförmigen Kristallen mit antiparalleler β-Konformation kristallisierten. Die molekularen Anordnungen in den Kristallen wurden mit Hilfe der Elektronenbeugung untersucht. In den späteren Stadien der Polymerisation setzten die gewachsenen Poly(L-valin)- und Poly-(L-iso1eucin)-Ketten die β-Struktur weiter fort, und ihre aktiven Enden wurden in den gebildeten Kristallen eingeschlossen, was ein-Einpendeln des Umsatzes bei einem niedrigen Wert zur Folge hatte. Poly(L-leucin) andererseits schien Kristalle mit gestreckten Ketten zu bilden, die zu einem sehr hohen Umsatz führten. Dies kann nicht ohne die Annahme erklärt werden, daß sich auf den in den Anfangsstadien der Polymerisation gebildeten β-Skelettkristallen α-Helix-Ketten bilden, wie dies im Falle des Poly(L-alanins) bereits früher berichtet wurde.
    Notes: In order to examine the effect of the steric hindrance by the polypeptide side chains on the growth mechanism of polypeptide crystals in the course of polymerization, we studied kinetics of the heterogeneous polymerization of L-valine N-carboxy anhydride (NCA), L-isoleucine NCA, and L-leucine NCA initiated by butylamine in acetonitrile and the structures and morphologies of the resultant polymers. In the early stages of polymerization, oligomers formed crystallized into thin ribbon-like crystals with the antiparallel β-conformation. The molecular arrangements in the crystals were studied by electron diffractions. In the later stages, the grown chains of poly(L-valine) and poly(L-isoleucine) continued to take the β-structure and their active ends were occluded in the crystals formed, which resulted in the levelling off of the conversion at a low value. On the other hand, poly(L-leucine) seemed to give the extended chain crystal, which made the conversion very high. This can not be accounted for without assuming the formation of β-helical chains onto the β-skeleton crystals formed in the early stages of polymerization as in the case of poly(L-alanine) reported previously.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750129
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  • 156
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    Mechanochemische Synthesen durch Polykondensation mit Polyestern als Grundsubstanz, 3.Teil 2 cf. Cr. Simionescu, C. Vasikiu Oprea, C. Neguleanu, Buletinul I.P.C. Iasi Fasc. 3-4, 45 (1969). Einige kinetische Aspekte der Mechanochemischen Polykondensation durch Schwingmahlung des Poly(oxyäthylenoxyterephthaloyl)s mit aliphatischen Diaminen (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 371-389 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The kinetics and the mechanism of the mechanochemical polycondensation process of poly(oxyethyleneoxyterephthaloyl) [poly(ethylene terephthalate)] with aliphatic diamines (ethylene- and hexamethylenediamine) were studied. First order kinetics was found and in addition the fact that a very small thermal activation energy is needed and that the diamines can react as radical acceptors.
    Notes: Kinetik und Mechanismus des mechanochemischen Polykondensationsvorganges von Poly(oxyäthylenoxyterephthaloyl) (Polyäthylenterephthalat) mit aliphatischen Diaminen (äthylen- und Hexamethylendiamin) wurden untersucht. Es wurde gefunden, daß die Reaktion nach einer Kinetik erster Ordnung abläuft, daß eine äußerst geringe thermische Aktivierungsenergie benötigt wird und daß die Diamine als Radikalakzeptoren auftreten können.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750203
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  • 157
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    Studies on the mechanism of redox polymerization initiated by N-haloamines and iron(II)Presented at the XXIVth IUPAC-Congress, Hamburg, Germany, September 1973. (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 413-423 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zur Aufklärung des Mechanismus der Redox-Polymerisation von Methylmethacrylat, die die Redox-Startsysteme N-Halogendiäthylamin + Fe2+ und Triäthylamin + Halogen + Fe2+ in wäßrigem Medium unter Lichtausschluß bewirken, wurden die Endgruppen des Polymeren nach der Farbstoff-Verteilungsmethode untersucht. Im Falle von Chlor als Halogen kommt es mit beiden Startsystemen lediglich zum Einbau von Aminogruppen in das Polymere in einem Ausmaß von ca. 1 Endgruppe pro Polymermolekül. Bei Verwendung des Startsystems Triäthylamin + Halogen + Fe2+ liegen darüber hinaus die in das Polymer eingebauten Aminogruppen zu einem großen Teil in quaternärer Form vor. Mit Brom als Halogen findet bei beiden Anregungssystemen lediglich ein Bromeinbau, nicht jedoch ein Einbau von Aminogruppen in das Polymere statt. Die Chlor enthaltenden Startsysteme haben sich für die Herstellung von solchen Polymeren nützlich erwiesen, die eine Aminogruppe nur an einem der beiden Kettenenden besitzen sollen.
    Notes: The mechanism of the redox polymerization of methyl methacrylate in aqueous medium in the dark was studied for the redox initiator systems N-halodiethylamine + Fe(II) and triethylamine + halogen + Fe(II), by analysis of the polymer end groups using the dye partition method. In the case of chlorine, both these initiator systems incorporate only the amino group into the polymer to an extent of about one group per polymer molecule. The polymers are found to be free from chlorine. Furthermore, a large portion of the total amino groups introduced into the polymer, using the initiator system triethylamine + halogen + Fe(II) are quaternary in nature. In the case of bromine, both the initiator systems introduce only a bromine atom and no amino group into the polymer. The initiator systems containing chlorine prove to be useful for the preparation of polymers containing amino groups at the one end only.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750206
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  • 158
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    Free radical polymerization of unconjugated dienes, 14.Part 13, cf. Makromol. Chem. 157, 111 (1972). Divinyl ketone in acetone solution at 50°C (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 457-466 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die radikalische Polymerisation des Divinylketons in Aceton bei 50°C wurde untersucht und mit den Resultaten bereits bekannter radikalischer Polymerisationen anderer 1,4-Diene vergl+hen. Es wird gezeigt, daß Divinylketon einer bicyclischen Cyclopolymerisation unterliegt, die derjenigen des Divinyläthers und des Divinylsulfids ähnlich ist. Die Cyclisierungskonstanten werden ermittelt und die Zusammensetzung der Polymere (als lineare, monocyclische und bicyclische Struktureinheiten) als Funktion der Monomerkonzentration, bei welcher die Polymerisation durchgeführt wurde, berechnet.
    Notes: The free radical polymerization of divinyl ketone at 50°C in acetone solutions was investigated. The results are compared with those already reported for the free radical polymerization of other 1,4-dienes. It is shown that divinyl ketone undergoes bicyclic cyclopolymerization in a similar way as divinyl ether and divinyl sulfide. The cyclization ratios are computed and the polymer composition, in terms of linear, monocyclic and bicyclic structural units, is calculated as a function of the monomer concentration at which the polymerization was carried out.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750210
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    Über die Bruttokinetik der Thermooxidation von HochdruckpolyäthylenVorgetragen beim XXIV. IUPAC-Kongreß, Hamburg, September 1973. (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 467-481 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The oxidation of molten foils (20μm) from high pressure polyethylene at 157°C and at 650 Torr (= 867 mbar) oxygen pressure was studied and kinetically analyzed for the period of maximum rate.The oxygen uptake, weight increase, and hydroperoxide formation start with a rate different from zero; the initial rate of carbonyl groups and volatile products is practically zero.The absorbed oxygen, except in the initial stage, shows a distribution of the ratio 1:1 between the polymer (predominantly as carbonyl groups) and volatile products (such as water). The average number of C-atoms in the volatile fragments was estimated from kinetic data to be 6 per O-atom.
    Notes: Die Oxidation von geschmolzenen Folien (20μm) aus Hochdruckpolyäthylen wurde bei 157°C und 650 Torr (= 867 mbar) Sauerstoffdruck untersucht und kinetisch in der Periode der maximalen Geschwindigkeit ausgewertet.Die Sauerstoffaufnahme, die Gewichtszunahme und die Hydroperoxidbildung beginnen mit einer von Null abweichenden Geschwindigkeit; die Anfangsgeschwindigkeit der Bildung von Carbonylgruppen und flüchtigen Produkten ist praktisch Null.Der absorbierte Sauerstoff verteilt sich außer im Anfangsverlauf im Verhältnis 1:1 zwischen dem Polymeren (vorwiegend als Carbonylgruppe) und den flüchtigen Produkten (in Form von Wasser). Die durchschnittliche Anzahl von C-Atomen in den flüchtigen Fragmenten wurde aus kinetischen Daten auf 6 pro O-Atom abgeschätzt.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750211
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  • 160
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    Copolymer statistics during esterification of syndiotactic poly(methacrylic acid) with diazomethane (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 523-534 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Nicht-neutralisierte und neutralisierte, syndiotaktische Poly(methacrylsäure) wird mit Diazomethan partiell verestert. Umsatz und Triadenverteilung der entstenhenden cosyndiotaktischen Methylmethacrylat-Methacrylsäure-Copolymeren und deren Fraktionen werden durch 1H-NMR-Spektroskopie bestimmt. Nicht-neutralisierte Poly(methacrylsäure) ergibt Copolymere, die in bezug auf den Umsatz heterogen sind; ihre Fraktionen zeigen näherungsweise eine BERNOULLI-Verteilung der Triaden. Neutralisierte Poly(methacrylsäure) liefert hingegen homogene Copolymere mit einer innerhalb der Meßgenauigkeit liegenden BERNOULLI-Verteilung der Triaden. Ein kinetischer Nachbargruppeneffekt tritt daher bei der Veresterung mit Diazomethan nicht auf. So hergestellte Copolymere weisen eine einfache konfigurative und kompositive Statistik auf, wie sie durch Copolymerisation der Monomeren bislang nicht hergestellt werden kann. Der Polyelektrolytcharakter der Copolymeren kann durch anschließende, vollständige Veresterung mit einem zweiten Diazoalkan eliminiert werden; die Statistik der so entstehendenen Copolymeren ist mit der der ursprünglichen Copolymeren identisch.
    Notes: Syndiotactic poly(methacrylic acid) is partially esterified as such or in its neutralized form with diazomethane. The extent of reaction and the triad distribution of the resulting cosyndiotactic methyl methacrylate-methacrylic acid copolymers and their fractions are determined by 1H-NMR spectroscopy. Unneutralized poly(methacrylic acid) yields copolymers which are heterogeneous with respect to conversion, the fractions of the copolymers possessing an approximate BERNOULLIan triad distribution. Neutralized poly(methacrylic acid) results in homogeneous copolymers whose triad distribution is BERNOULLIan within accuracy of measurement. A kinetic neighboring group effect is therefore not operative during the esterification with diazomethane. Copolymers may thus be prepared which are of simple configurational and compositional statistics, not obtainable at present by copolymerization of monomers. The polyelectrolyte character of the copolymers may be eliminated by consecutive, complete esterification with a second diazoalkane, the statistics of the derived copolymers being identical with that of the precursor copolymers.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750215
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  • 161
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    Formation of polyion complexes between polycarboxylic acids and polycations carrying charges in the chain backbonePresented at the XXIV th IUPAC Congress, Hamburg, Germany, September 1973. (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 583-592 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Bildung von Polyionen-Komplexen in wäßrigem Medium zwischen Polykationen, die Ladungen in der Kette tragen, und Polycarbonsäuren, wie Polymethacrylsäure (PMAA), Polyacrylsäure (PAA) und Polyitaconsäure (PIA), wurde untersucht. Es wurde gefunden, daß die Polykationen stabilere Komplexe bilden als die entsprechenden niedermolekularen Kationen und daß neben der Kettenlänge die Dissoziationskonstanten und die Hydrophobie die Bildungsfähigkeit der Polyionen-Komplexe beeinflußte. Die Zusammensetzung der Komplexe zwischen Polykationen und Polycarbonsäuren wurde vor allem durch den Dissoziationsgrad (α′) der Polycarbonsäuren bestimmt.Aus diesen Ergebnissen ist zu schließen, daß die Komplexe durch die kooperativen Wechselwirkungen zwischen zwei Polymerketten, die entgegengesetzte Ladungen tragen, gebildet werden und daß die Polyionen-Komplexe reversibel Schleifen-, Leiter- und dazwischenliegende Strukturen ausbilden.
    Notes: The formation of polyion complexes in aqueous medium between polycations carrying charges in the chain backbone and poly(carboxylic acid)s, such as poly(methacrylic acid) (PMAA), poly(carboxylic acid) (PAA), and poly(itaconic acid) (PIA), were studied. It was found that polycations formed more stable complexes than their corresponding low molecular weight cations and that in addition to the chain length, dissociation constants and the hydrophobicity dominated the ability of the formation of a polyion complex. The compositions of the complexes between polycation and polycarboxylic acid were defined mainly by the degree of dissociation (α′) of the poly(carboxylic acid).From these results it is concluded that the complexes are formed by the cooperative interactions between two polymer chains which have charges of opposite sign and the structures of polyion complexes can accept reversible states like loops, ladders, and their intermediate shapes.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750219
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  • 162
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    “Entanglement” concept and chain conformations in bulk amorphous polymers (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 641-654 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wird gezeigt, daß die zur Zeit vorhandenen Kenntnisse über die Struktur von amorphen Blockpolymeren mit der Vorstellung von der Existenz eines beträchtlichen Anteils an Nahordnung der Kettensegmente übereinstimmen. Es wird vermutet, daß die starke Veränderung der Molekulargewichtsabhängigkeit der NEWTONschen Viskosität von Polymerenschmelzen beim Erreichen eines kritischen Molekulargewichts Mc für die Bildung von „Verhakungen“ hauptsächlich bedingt ist durch den übergang von Makromolekülen aus der gestreckten Konformation in eine solche mit statistischen Faltungen der Makromoleküle. Schließlich werden empirische Abhängigkeiten ermittelt, welche die Werte der Packungskoeffizienten eines Polymeren im kristallinen Zustand sowie die „besten“ numerischen Werte von Mc mit molekularen Parametern eines Polymeren verbinden.
    Notes: It is shown that the presently available information on the structure of bulk amorphous polymers is consistent with the concept of the existence of a substantial amount of short-range segmental order. It is suggested that the sharp change of molecular-weight dependence of NEWTONian viscosity of polymer melts with the approach to the critical “entanglement” molecular weight Mc is brought about mainly by the transition from the extended-chain conformation of the macromolecules into the statistically folded-chain conformation. Finally, empirical relationships are obtained which relate the values of polymer packing coefficients in the crystalline state as well as the “best” numerical values of Mc with molecular parameters of a polymer.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750223
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  • 163
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    IUPAC.This journal announces exclusively IUPAC meetings. Announcements of national and other international meetings are to be found in “Mitteilungen” of Die Angewandte Makromolekulare Chemie International symposium on macromolecules (SIM). July 26-31, 1974 Rio de Janeiro/Brazil (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 701-701 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750231
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  • 164
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    Use of pyridine bases as shift solvents for the analysis of novolak resin by NMR spectroscopy (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1001-1005 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750326
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  • 165
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    Die kationische ε-caprolactam-polymerisation, 6. Amidin-Endgruppen bei der mit Caprolactam-hydrochlorid initiierten Caprolactam-Polymerisation (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1015-1015 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750329
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  • 166
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    The rôle of carbocations in cationic polymerization (polycondensation) of π-, σ-, and n-donor monomersIonic Polymerization, 2; Part 1, cf.1. (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1039-1064 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Funktion von Carbokationen bei der kationischen Polymerisation wird diskutiert, wobei unterschieden wird zwischen π- (d.h. Alkenen und Arenen), σ- (d.h. Alkanen) und n-Donator-Monomeren (d.h. Äthern, Sulfiden und Stickstoff-Verbindungen) als die reaktiven Nucleophile. Der Mechanismus der Initiierungsstufe bei der Alken-Polymerisation wird geprüft im Hinblick auf protische (d.h. einen Coinitiator enthaltende) und aprotische Systeme. So kann z. B. die durch Aluminiumbromid katalysierte Polymerisation von Isobutylen neben den konjugierten Protonsauren Zwischenprodukte der Bromalanat-Bildung im aprotischen Medium mit enthalten, die jedoch eine Eliminierung erleiden konnen unter Bildung von HBr im ursprunglich saurefreien System. Das Auftreten von Dialkylhalonium-Ionen in Halogenalkan-Lösungsmittelsystemen ist ebenfalls von wesentlichem Interesse und mag die in der Reihenfolge RJ〉RBr〉RCl zunehmende Desaktivierung erklären.Die oxidative Polykondensation von π-Donator-Arenen (wie Benzol) und σ-Donator-Alkanen (wie Methan) wird im Kontext des generellen Carbokation-Konzepts diskutiert unter Einbeziehung der trivalenten Carbeniumionen-Zwischenprodukte im ersten Fall und der pentakoordinierten Carboniumionen im letzteren Fall, da die reaktiven Alkylie-rungs-Agenzien für die ionischen Wachstumsreaktionen verantwortlich sind. n-Donator-Monomere wie Äther, Sulfide oder verschiedenartige Stickstoffverbindungen unterliegen der Polymerisation via nucleophilen Substitutionsreaktionen an carbokationischen Stellen intermediärer alkylierter oder protonierter Onium-Ionen.
    Notes: The rôle of carbocations in cationic polymerizations is discussed, differentiating σ- (i.e. alkene and arene), π- (i.e. alkane) and n-donor (i.e. ether, sulfide, nitrogen compound) monomers as the reactive nucleophiles. The mechanism of the initiation step in alkene polymerization is evaluated considering both protic (i.e. coinitiator containing) and aprotic systems. The aluminum bromide catalyzed polymerization of isobutylene, as an example, can involve besides the conjugate protic acid, bromoalanation intermediates in aprotic media, which, however, themselves rapidly can undergo elimination, forming HBr in the originally acid free system. The involvement of dialkylhalonium ions in alkyl halide solvent systems is also of substantial interest and may explain increasing deactivation in the order RI〉RBr〉RCl. Oxidative polycondensation of π-donor arenes (such as benzene) and σ-donor alkanes (such as methane) is discussed in the context of the general carbocation concept, involving trivalent carbenium ion intermediates in the former and pentacoordinated carbonium ions in the latter case, as the reactive alkylating agents responsible for the ionic propagation reactions. n-Donor monomers, such as ethers, sulfides or miscellaneous nitrogen compounds, undergo polymerization via nucleophilic displacement reactions on the polarized carbocationic sites of intermediate alkylated or protonated onium ions.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750402
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  • 167
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    Study of the isothermal bulk polymerization of vinyl acetate by differential scanning calorimetry (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1507-1511 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Mit Hilfe der Abtast-Kalorimetrie (DSC) wurden der Verlauf und die Kinetik der isothermen Polymerisation des Vinylacetates in Masse studiert. Als Initiator wurde 2,2′-Azoisobutyronitril verwendet. Die Polymerisation wurde bei Temperaturen zwischen 55 und 70°C mit konstanter Initiatormenge, 5,0.10-2 mol/l, ausgeführt. Die Polymerisationswärme beträgt bei 60°C - 19,5 kcal/mol und nimmt mit steigender Temperatur ab. Es wurden auch Geschwindigkeitskonstanten der Polymerisation im stationären Zustand und aus ihnen die Bruttoaktivierungsenergie zu 21,6 kcal/mol bestimmt. Eine andere Reihe von Experimenten wurde bei 60°C mit verschiedenen Initiatormengen durchgeführt. Die Bruttogeschwindigkeit der Polymerisation bei kleinen Umsätzen ist der Wurzel der Initiatormenge proportional, was dem angenommenen kinetischen Schema entspricht.
    Notes: The course and kinetics of the isothermal bulk polymerization of vinyl acetate were studied by differential scanning calorimetry. The initiator used was 2,2′-azoisobutyronitrile. The polymerization was investigated at temperatures between 55 and 70°C at constant initiator concentration, 5,0.10-2 mol/l. The heat of polymerization at 60°C is - 19,5 kcal/mol and decreases with increasing temperature. Initial rate constants for the polymerization were also determined and from them the overall activation energy, 21,6 kcal/mol. Another series of polymerization experiments were performed at 60°C with variable amounts of the initiator. The overall rate of polymerization at low degrees of conversion depends on the square root of the initiator concentration which is in agreement with the assumed kinetic scheme.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750512
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  • 168
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    Cationic polymerization of cyclic sulfides, 5Part 4, cf.28. Polymerization of propylene sulfide with triethyloxonium tetrafluoroborate (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1513-1529 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Polymerisation von Propylensulfid (1) unter dem Einfluß von Triäthyloxoniumtetrafluoroborat (TEFB) in Methylenchlorid wurde untersucht. Die Zeit-Umsatz-Kurven zeigen, daß die Polymerisation in zwei Phasen verläuft: anfangs eine sehr schnelle nicht stationäre Phase A, die bei begrenzter Ausbeute aufhört, und daran anschließend eine viel langsamere Phase B, die zu einem quantitativen Umsatz führt Die Abbruchreaktion der Phase A ist erster Ordnung in bezug auf den Initiator und ist unabhängig von der Monomerkonzentration. Als Mechanismus der Abbruchreaktion wird die Bildung eines haupt-sächlich zwölf-gliedrigen zyklischen Sulfoniumsalzes am Ende der Polymerkette vorgeschlagen. Das Verhaltnis der Geschwindigkeitskonstanten fur die Wachstums- und Abbruchreaktionen bei 0°C in CH2CL2, ist 9 dm3 mol-1. Aus der Kinetik wird geschlossen, daß die Phase B durch die langsame Bildung eines drei-gliedrigen zyklischen Sulfonium-salzes durch einen intramolekularen nukleophilen Angriff der letzten Sulfidgruppe der Polymerkette am α-Kohlenstoff neben dem Sulfoniumsalz ausgelöst wird. Ein weiterer Beweis für diese Art der Re-initiierung wird aus der Beobachtung erhalten, daß einfache Trialkylsulfoniumsalze die Polymerisation nicht starten können, während unter identischen Bedingungen 2-Thia-alkylsulfoniumsalze Polymerisationen ohne eine Phase A ergeben, die ähnlich wie die Phase B von mit TEFB gestarteten Reaktionen verlaufen. Eine “Back-biting”-Reaktion, ähnlich der Abbruchreaktion, ist für den Abbau des Polymeren (hauptsächlich) in zyklische Tetramere verantwortlich.Die Molekulargewichte der Polymeren wurden mit Hilfe der Gelpermeationschromato-graphie gemessen und stimmen mit dem vorgeschlagenen Mechanismus gut überein.
    Notes: Time-conversion curves show that the polymerization of propylene sulfide (1) by triethyloxonium tetrafluoroborate (TEFB) in methylene chloride consists of an initial very fast, non-stationary stage A and a much slower subsequent stage B which leads to quantitative conversion. The termination reaction of stage A is of first order with respect to initiator concentration and is independent of monomer concentration. The proposed mechanism for this termination is the formation of a (mainly) 12-membered cyclic sulfonium salt at the end of the polymer chain. The ratio of the rate constant of propagation to the rate constant of termination at 0°C in CH2Cl2 is 9 dm3 mol-1. From the kinetics, it is concluded that stage B is initiated by slow formation of a three-membered cyclic sulfonium salt by an intramolecular nucleophilic attack of the last sulfide function of the polymer chain on the α-carbon next to the sulfonium salt. Further evidence for this kind of re-initiation is obtained from the observation that simple trialkylsulfonium salts are very poor initiators or completely incapable of initiating the polymerization, whereas under identical conditions 2-thia-alkylsulfonium salts give polymerizations without stage A which are similar to the stage B of the TEFB-initiated reactions. A backbiting reaction, similar to the termination reaction, is responsible for the degradation of polymer (mainly) into cyclic tetramer. The molecular weights of the polymers, measured by gel permeation chromatography, are in reasonable agreement with the proposed mechanism.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750513
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  • 169
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    Kernresonanzspektroskopische mikrostrukturanalyse von vinylchlorid-propen-copolymeren, 21. Mitteilung: cf.1. NMR-spektroskopische bestimmung der taxieparameter aus den häufigkeiten konfigurativer triaden (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1579-1596 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Copolymers from vinylchloride (VC) und propene (P) were investigated by high resolution proton magnetic resonance at 100 MHz. The methyl resonance of P units and the methine resonance of VC units in the decoupled spectra were assigned to configurational triads by the aid of a graphical separation method.A plot was developed to determine the cotacticity parameters Σs and Σp; in addition, the “ultimate model” has been checked by this method. Using the dependence of the cotacticity parameters on polymerization temperature the activation enthalpies of tactic propagation steps have been determined.
    Notes: Copolymere aus Vinylchlorid (VC) und Propen (P) wurden durch hochauflösende magnetische Protonenresonanz bei 100 MHz untersucht. Die Methylresonanz der P-Einheiten und die entkoppelte Methinresonanz der VC-Einheiten konnten anhand eines graphischen Trennverfahrens konfigurativen Triaden zugeordnet werden.Es wurde eine graphische Darstellung entwickelt, die sowohl die Werte der Cotaxieparameter Σs und Σp liefert als auch ein Test für das “ultimate model” ist. Aus der Abhängigkeit der Cotaxieparameter von der Polymerisationstemperatur konnten die Aktivierungsenthalpien der taktischen Wachstumsschritte ermittelt werden.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750518
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  • 170
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    13C-NMR spectra of polyalkenylenes and of some diolefin polymers and copolymers (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1627-1640 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Untersuchung von 13C-NMR-Spektren von ungesättigten Homopolymeren (Polyalkenylenen und Polypentadienen) hat gezeigt, daß man zwischen 1,2- und 1,4-Strukturen und zwischen einer cis- und trans-Konfiguration der Doppelbindungen entlang der Kette unterscheiden kann. Durch Anwendung dieser Technik ist es möglich geworden, Klarheit über die Struktur und die relative Orientierung der Monomerinheiten in alternierenden Copolymeren des Isoprens mit Acrylnitril oder Propen zu erhalten. Mit derselben Methode wurden auch Copolymere des Butadiens mit den beiden letzteren Comonomeren geprüft.
    Notes: The examination of 13C-NMR spectra of some unsaturated homopolymers (polyalkenylenes and polypentadienes) has shown that it is possible to distinguish beween 1,2-and 1,4-structures and between cis- and trans-configuration of the double bonds along the chain. By using this technique, it has been possible to obtain evidences on the structure and the relative orientation of monomeric units in alternating copolymers of isoprene with acrylonitrile or propene. Copolymers of butadiene with these two latter comonomers were also examined by this method.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750521
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  • 171
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    The effect of chain length on the solid-state polymerization of N-alkylmaleimides (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 833-841 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: N-Alkylmaleimide vom N-Methyl-bis zum N-Octadecyl-Derivat wurden durch γ-Strahlung im festen Zustand polymerisiert. Die Polymerisation weist während der Bestrahlung im allgemeinen eine S-förmige Umsatzkurve auf, mit hohen Geschwindigkeiten und quantitativem Umsatz bei Temperaturen von 10°C unterhalb des Schmelzpunktes. Die Geschwindigkeiten waren nach der Bestrahlung niedriger und zeigten eine typische Annäherung an einen Grenzumsatz. Die Polymerisationsgeschwindigkeiten nahmen mit der Temperatur und der Bestrahlungsdosis sowie mit der Länge der Alkylkette zu. N-Methylmaleimid zeigte eine hohe Geschwindigkeit bei der Polymerisation in Substanz, die der Flüchtigkeit des Monomers zugeschrieben wurde.
    Notes: N-alkylmaleimides from the N-methyl to the N-octadecyl derivative were polymerized in the solid state by γ-radiation. Polymerization during irradiation generally showed sigmoidal conversion curves with high rates and complete conversion 10°C below the melting point. Post-irradiation rates were lower and showed the typical approach to a “limiting” conversion. The polymerization rates increased with temperature and radiation dose and with the length of the alkyl chain. N-methylmaleimide had a high rate of in-source polymerization which was attributed to the volatility of the monomer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750311
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  • 172
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    Kinetik und Mechanismus der radikalischen Copolymerisation von Styrol mit Acrylnitril und Methylmethacrylat in Anwesenheit von KomplexbildnernVorgetragen beim XXIV. IUPAC-Kongreß, Hamburg, September 1973. (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 881-891 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The kinetics of the initiated copolymerization in the presence of zinc chloride or diethylaluminumchloride was studied. For the system styrene/methyl methacrylate/zinc chloride (initiator: benzoylperoxide) it was found that (besides the copolymer) polystyrene was formed. This was explained by a cationic polymerization in competition with the radical process.A scheme was proposed which describes the copolymerization of the two polar monomers with the non-polar one together with an equation of the composition of the ternary copolymers obtained in the presence of one of the complex forming compounds.
    Notes: Die Kinetik der initiierten Copolymerisation in Anwesenheit von Zinkchlorid oder Diäthylaluminiumchlorid wurde untersucht. Für das System Styrol/Methylmethacrylat/Zinkchlorid (Initiator Benzoylperoxid) wurde die Bildung von Polystyrol festgestellt (neben der Bildung von Copolymeren), die auf eine neben der radikalischen Polymerisation verlaufende kationische Polymerisation zurückgeführt wurde.Es wurde ein Schema der Stadien des Kettenwachstums der Copolymerisation zweier polarer Monomere mit einem nicht polaren Monomer vorgeschlagen sowie eine Gleichung der Zusammensetzung ternärer Copolymere, die im Beisein eines Komplexbildners erhalten wurden.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750315
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  • 173
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    Über polyarylenalkenylene und polyheteroarylenalkenylene, 32. Mitt.: G. Kossmehl, M. Härtel, G. Manecke, Makromol. Chem. 131, 37 (1970). Synthesen und charakterisierung von poly(1,3,4-thiadiazol-2,5-ylenvinylenarylenvinylene)n und einigen ihrer oligomerenHerrn Professor Dr. Heinrich Hellmann zum 60. Geburtstag gewidmet (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1359-1370 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Various poly(1,3,4-thiadiazol-2,5-ylenevinylenearylenevinylene)s (5a-c) and their oligomers (3a-e) were prepared via the Knoevenagel condensation of 2,5-dimethyl-1,3,4-thiadiazole (1) with mono- and dialdehydes of the benzene and thiophene series. The structure of the obtained oligomers and polymers was confirmed by their elemental analysis as well as by their IR-, electronic, and mass spectra. Soluble compounds were also applied to NMR spectroscopy. The electrical conductivity and thermostability of the polymers were investigated.
    Notes: Bei der Knoevenagel-Kondensation von 2,5-Dimethyl-1,3,4-thiadiazol (1) mit Mono- und Dialdehyden der Benzol- und Thiophenreihe wurden einige Poly(1,3,4-thiadiazol-2,5-ylenvinylenarylenvinylene) (5a-c) und einige ihrer Oligomere (3a-e) erhalten. Die Struktur der erhaltenen Substanzen wurde durch Elementaranalyse, IR-Spektren, Elektronenspektren, Massenspektren und - soweit die Löslichkeit der Verbindungen es zuließ - auch durch 1H-NMR-Spektren bestätigt. Ferner wurde die elektrische Leitfähigkeit und die Thermostabilität der Substanzen untersucht.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750502
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  • 174
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    Oligooctenamere, charakterisierung und massenspektrometrische untersuchungenHerrn Professor Dr. Heinrich Hellmann zum 60. Geburtstag gewidmet (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1395-1409 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The homologous series of cyclooctene oligomers was prepared by means of the metathesis reaction. The oligomers were separated and purified by gel permeation chromatography. Boiling points and indices of refraction were determined and the spectroscopic behavior was investigated. In particular the mass spectra of the oligomers are discussed in comparison with those of cyclododecene oligomers, of 1,5-cyclooctadiene oligomers, and of acyclic oligobutadienes. The results confirm the cyclic structure of oligomers prepared by ring-opening polymerisation of cycloolefins. Further, under suitable conditions the mass spectra can be a means to distinguish between cyclic and acyclic hydrocarbons.
    Notes: Die homologe Reihe der Oligomeren des Cyclooctens wurde mit Hilfe der Metathese-Reaktion dargestellt; die Oligomeren wurden gelchromatographisch getrennt und gereinigt. Ihre Siedepunkte und Brechungsindices wurden bestimmt, und ihr spektroskopisches Verhalten wurde untersucht. Insbesondere werden die Massenspektren der Oligomeren im Vergleich zu denen der Oligomeren des Cyclododecens, des 1,5-Cyclooctadiens und acyclischer Oligobutadiene diskutiert. Die Ergebnisse bestätigen die cyclische Struktur der durch ringöffnende Polymerisation von Cycloolefinen erhaltenen Oligomeren. Darüberhinaus wird gezeigt, daß die Massenspektrometrie unter geeigneten Bedingungen herangezogen werden kann, um zwischen cyclischen und acyclischen Kohlenwasserstoffen zu unterscheiden.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750505
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  • 175
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    Vinyl polymerization, 314Part 313, cf. Y. Ishikawa et al., Nippon Gomu Kyokaishi (J. Soc. Rubber Ind., Japan) 47, 193 (1974) Polymerization of vinyl monomers photosensitized by 1,4-bis(pentamethylene)-2-tetrazene (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1497-1505 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Photopolymerisation von Vinylmonomeren kann durch 1,4-Bis(pentamethylen)-2-tetrazen (1) sensibilisiert werden. Die Kinetik der Photopolymerisation wurde im Falle des Styrols (St) untersucht. Die Polymerisationsgeschwindigkeit ist proportional der halben Potenz der Konzentration von 1 und proportional der ersten Potenz der St-Konzentration. Der versuchsweise für die Gesamtreaktion vorgeschlagene Mechanismus wird anhand der Versuchsergebnisse diskutiert.
    Notes: The photopolymerization of vinyl monomers can be sensitized by 1,4-bis(pentamethylene)-2-tetrazene (1). The kinetics of the photopolymerization was investigated in the case of styrene (St). The rate of polymerization was found to be proportional to the one half power of the concentration of 1 and to the first power of the concentration of St. A plausible mechanism proposed for the overall reaction is discussed in the light of the experimental results.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750511
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  • 176
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    Hemicelluloses fractionation (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1535-1542 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Eigenschaften der aus Phragmites communis und Arundo donax erhaltenen Hemicellulosen wurden untersucht. Aus den experimentellen Daten folgt, daß die Molekulargewichtsverteilung der Hemicellulosen vom untersuchten Produkt abhängig ist. Die parallele Existenz der chemischen Inhomogenität und der Molekulargewichtsverteilung bestimmt die bimodale Art der durch Fraktionierung erhaltenen differentiellen Verteilungskurven.
    Notes: The solution properties of the hemicelluloses obtained from Phragmites communis and Arundo donax were investigated. The presented experimental data led to the conclusion that the molecular weight distribution of hemicelluloses depends on the studied product. The parallel existence of the chemical inhomogeneity and the molecular weight distribution determine the bimodal aspect of differential distribution curves obtained by fractionation.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750515
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    Kernresonanzspektroskopische mikrostrukturanalyse von vinylchlorid-propen-copolymeren, 1. NMR-spektroskopische bestimmung der bruttozusammensetzung und der kompositiven triaden für vinylchlorid-propen-copolymere (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1561-1578 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Copolymers from vinylchloride (VC) and propene (P) were investigated by high resolution proton magnetic resonance at 100 MHz. By comparison with the spectra of the homopolymers the resonances of the copolymers spectra have been assigned, the overall composition determined and the reactivity ratios derived.Using the spin decoupling technique the methine resonance of the VC units splits into five peaks. Their assignment to compositional and configurational triads has been successful by applying a graphical separation method. The validity of the copolymerization model used for the determination of the reactivity ratios has been checked by means of the measured triad frequencies.
    Notes: Copolymere aus Vinylchlorid (VC) und Propen (P) wurden durch hochauflösende magnetische Protonenresonanz bei 100 MHz untersucht. Aus dem Vergleich mit den Homopolymerspektren konnten die Resonanzkomplexe der Copolymerspektren zugeordnet, die Bruttozusammensetzung der Copolymeren ermittelt und die Copolymerisationsparameter berechnet werden.Der Methinresonanzkomplex der VC-Einheiten ließ sich durch Spinentkopplung in fünf Peaks aufspalten. Ihre Zuordnung zu kompositiven und konfigurativen Triaden erfolgte anhand eines graphischen Trennverfahrens. Das zur Ermittlung der Copolymerisationsparameter verwendete Wachstumsmodell wurde mit den gemessenen Triadenhäufigkeiten auf seine Gültigkeit hin geprüft.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750517
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    Relation entre la structure et les propriétés mécaniques dynamiques de polyéthylènes haute pression chlorés (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 1611-1625 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The dynamic mechanical properties of chlorinated polyethylenes with well determined microstructures are studied at low frequency and a temperature range between -140°C and +240°C. An interpretation of the mechanical behaviour of these products as a function of the chemical constitution of their chains is proposed.
    Notes: Les propriétés mécaniques dynamiques de polyéthylènes chlorés de microstructures bien déterminées sont étudiées en basse fréquence dans un domaine de température compris entre -140°C et + 240°C. Une interprétation du comportement mécanique de ces produits en fonction de la constitution chimique de leurs chaǐnes est proposée.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750520
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  • 179
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    Studies on the polymerization of vinyl compounds in the presence of metal salts, 9Part 8: H. NARITA, S. SAKATA, T. ODA, and S. MACHIDA, Angew. Makromol. Chem. 32, 91 (1973).. On the initiation mechanism of polymerization of acrylamide by ceric saltDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 111-118 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Um den Initiierungsmechanismus der Polymerisation von Acrylamid durch Cer(IV)-Salz zu klären, wurde die Komplexverbindung von Cer(IV)-Salz mit Acrylamid und seinen methylierten Derivaten mittels IR- und NMR-Spektrometrie untersucht. Der Zerfall des Komplexes wurde durch Messung der Geschwindigkeit des Verbrauchs von Cer(IV)-Ionen verfolgt. Aus den Versuchsergebnissen kann geschlossen werden, daß der Sauerstoff des Acrylamids zur Komplexierung mit Cer-Ionen koordiniert und daß ein Radikal durch Abspaltung eines Wasserstoffatoms der Amidgruppe des Komplexes entsteht und so die Polymerisation initiert wird.
    Notes: In order to elucidate the initiation mechanism of the polymerization of acrylamide by ceric salt, the complexation of ceric salt with acrylamide and its methylated derivatives was investigated by IR and NMR spectrometry. The decomposition of the complex was also studied by determining the rate of ceric salt consumption. From the results it was concluded that the oxygen of acrylamide coordinates with the ceric ion to form the complex and that a radical is produced by abstraction of a hydrogen atom from the amide group of the molecule to initiate the polymerization.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750113
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  • 180
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    Electrostatic effect on electron-transfer reactions of cobalt(III)-poly(4-vinylpyridine) complexesDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 161-169 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Reduktion des cis-[Co(en)2PVPCl]2+-Komplexes (1) (PVP = Polyvinylpyridin) mit Ferroionen oder Ferrochelat-Ionen wurde untersucht. Die Reduktion mit Fe2+ verläuft wegen elektrostatischer Abstoßung langsamer als die des monomeren Analogons, cis-Chlorobis-(ethylendiamin)-pyridin-kobalt(2+) (cis-[Co(en)2PyCl]2+). Dagegen ist die Reduktion mit [Fe-(edta)]2- um das Zwanzigfache beschleunigt. Mit zunehmendem Koordinationsgrad steigt der Beschleunigungsfaktor, und mit zunehmender Ionenstärke nimmt der Faktor ab. Es wurde gefunden, daß die Beschleunigung auf die elektrostatische Anziehung zwischen dem Polymer-Komplex als einem Polykation und dem Reduktionsmittel zurückzuführen ist. Die elektrostatische Wirkung wird im Vergleich zu den mit Polyelektrolyten katalysierten ionischen Reaktionen diskutiert.
    Notes: Reductions of cis-[Co(en)2PVPCl]2+ (1) [PVP = poly(4-vinylpyridine)] by ferrous aquoions and ferrous chelate ions were studied. The rate of reduction by Fe2+ is small compared to that of the monomeric analogue, cis-chlorobis(ethylenediamine)pyridine cobalt(2+) (cis-[Co(en)2PyCl]2+) due to the electrostatic repulsion. On the other hand, the reduction by [Fe-(edta)]2- is accelerated by a factor of 20. With increasing degree of coordination the acceleration factor increases, and with increasing ionic strength the factor decreases. The acceleration was found to be due to the electrostatic attraction of the reductant by the polymer as a polycation. The electrostatic effect is discussed in comparison with the catalysis of polyelectrolytes in ionic reactions.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750117
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    Heats of dilution of atactic polystyrene in ethyl acetateDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 209-216 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Verdünnungswärme und die Volumenänderung des Systems Polystyrol/Äthylacetat wurden gemessen. Es wurde gezeigt, daß die positiven Werte der enthalpischen Wechselwirkungsparameter und diejenigen des Exzeß-Volumens bei ungefähr derselben Molmasse des Polymers in negative übergehen. Dies wird erklärt mit einer drastischen Änderung der Konformation der Polymermoleküle beim Erreichen einer bestimmten Molmasse.
    Notes: The heats of dilution and the volume change for the system polystyrene/ethyl acetate were measured. It was shown that the values of the interaction heat parameter as well as those of the excess volume change their positive sign to a negative one at about the same molar mass of the polymer. This is explained in terms of drastic changes of the conformation of the polymer molecules as soon as a certain molar mass is attained.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750122
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    13C-NMR spectrum of equibinary (cis-1,4 - 1,2) polybutadieneDedicated to Prof. Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 237-245 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die protonenentkoppelten 13C-Kernresonanzspektren (natürliche Isotopenhäufigkeit) des äquibinären (cis-1,4 - 1,2)-Polybutadiens wurden gemessen. Alle Resonanzen im aliphatischen Bereich wurden zugeordnet; hierbei wurden geschätzte Korrekturterme für die chemischen Verschiebungen im vorliegenden System zusammen mit den GRANTschen Parametern verwendet. Für jeden Peak wurde außerdem angegeben, ob er zu einer Diade oder Triade von cis-1,4- und 1,2-Einheiten gehört. Die gemessenen relativen Intensitäten der Peaks stimmten mit den berechneten Intensitäten überein; der Rechnung wurde eine regellose Verteilung der cis-1,4- und der 1,2-Einheiten zugrunde gelegt. Die gaschromatographische Analyse der Ozonolyseprodukte der Polymere zeigte ebenfalls eine regellose Verteilung der beiden Einheiten an.
    Notes: The proton decoupled natural abundant 13C-NMR spectra of equibinary (cis-1,4 - 1,2)-polybutadiene were measured. Assignments of spectra were made for all peaks of the aliphatic range using chemical shift corrective terms estimated for the present system together with GRANT's parameters. Each peak was interpreted in terms of the diad or triad of cis-1,4 and 1,2 units. The relative intensities of the peaks were in good agreement with the calculated ones from the random assumption with respect to the distribution of cis-1,4 and 1,2 units. The gas-chromatographic analysis of the ozonolysis product of the polymers also showed that the sequence distribution of cis-1,4 and 1,2 units was random.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750125
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    Mechanical denaturation of high polymers in solutions, 32Part 31: cf. Chem. High Polymers [Tokyo] (Kobunshi Kagaku) 30, 511 (1973).. effect of flow pattern on shearing stress-induced crystallization of poly(vinyl alcohol) from its aqueous solutionDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 247-254 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Kristallisation von Polyvinylalkohol (PVA) wurde in wäßriger Lösung bei stationärer Strömung untersucht. Die fibrillären Kristalle erscheinen kurz unter der Oberfläche der Lösung nach einigen Sekunden Rühren und wachsen allmählich auf. Die fibrillären Kristalle erscheinen sogar aus einer 0,05 proz. Lösung. Der Verlauf der Kristallisation von PVA in einer stationären Strömung wird in sieben Typen eingeteilt. Die Geschwindigkeit der Fällung nimmt mit abnehmendem Abstand zwischen der Oberfläche des Rührers und der Wand des Reagenzglases oder mit dem Durchmesser des Rührers zu.
    Notes: The crystallization of poly(vinyl alcohol) (PVA) from an aqueous solution was carried out under a steady-state flow. The fibrillar crystals occur just under the surface of the solution after a few seconds of stirring and they grow gradually. The fibrillar crystals are produced even from a 0,05% solution. The process of crystallization of PVA under steady-state flow was classified in seven types. The rate of precipitation increases with decreasing distance between the surface of a cylindrical stirrer and the wall of a test tube or with the diameter of the stirrer.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750126
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    Crystallization of polypeptides in the course of polymerization, 6Part 5, cf.5.. Effect of the heteroatom attached to the β-carbon on the crystal growthDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 301-310 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Wachstumsmechanismus von Polypeptiden, die das Heteroatom S am β- oder γ-Kohlenstoff enthalten und die in der beta;-Konformation bzw. der α-Helix-Konformation auftreten, wurde während des Verlaufs einer heterogenen Polymerisation untersucht. Dabei wurden von uns Untersuchungen der Kinetik der heterogenen Polymerisation von S-Methyl-L-cystein-LEUCHS-Anhydrid (NCA), S-Benzyloxycarbonyl-L-cystein-NCA und L-Methionin-NCA mit Butylamin als Initiator in Acetonitril und der Morphologie der gebildeten Polymere durchgeführt. Wie zu erwarten war, konnte bestätigt werden, daß polymere S-substituierte L-Cysteine, die nur die β-Struktur als Ordnungsform annehmen, Kristalle mit Kettenfaltung ergaben. In allen untersuchten Fällen bildeten sich in den Anfangsstadien der Polymerisation lange, bändchenförmige Kristalle, die mit fortschreitender Polymerisation sich zu runden, stäbchenförmigen Fasern verdickten. Für den Wachstumsmechanismus dieser Polymerkristalle wird ein mögliches Modell vorgeschlagen, wobei die unregelmäßige β-Struktur zugrunde gelegt wurde. Es konnte gezeigt werden, daß Poly(L-Methionin) mit α-Helixstruktur Kristalle mit gestreckten Ketten ergibt.
    Notes: In order to examine the growth mechanisms of polypeptides with a heteroatom, S, on the β- and γ-carbons which give the α-conformation and the α-helical conformation, resp., in the course of a heterogeneous polymerization, we have studied kinetics of the heterogeneous polymerization of S-methyl-L-cysteine N-carboxy anhydride (NCA), S-benzyloxycarbonyl-L-cysteine NCA and L-methionine NCA initiated by butylamine in acetonitrile and the morphologies of the resultant polymers. As was anticipated, it has been verified that poly-(S-substituted-L-cysteines), which take only the β-structure as the ordered form, gave the chain-folded crystals. In all the cases studied, long lath-like crystals formed in the early stages of polymerization thickened into round rod-like fibers as the polymerization proceeded. A possible model was proposed for the growth mechanism of these polymer crystals, taking into account the cross-β-structure. It has been revealed that poly(L-methionine) with the α-helical structure gave the extended chain crystals.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021750130
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    The cationic polymerization of ketene acetals and the preparation and characterization of poly(1,3-diketones) (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2821-2836 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Verschiedene Ketenacetale (1a-d) wurden dargestellt, und ihre homogene und heterogene kationische Polymerisation in Substanz und in Lösung im Temperaturbereich von ca. 100 bis -100°C wurde untersucht.Die Mehrzahl der in Lösung gebildeten Produkte waren zähflüssige, hellgelbe Flüssigkeiten oder klebrige, rote Festkörper. Die Polymerisation in Substanz mit kristallinen, wenig löslichen Initiatoren ergab weiße, wachsartige oder pulvrige Polymere. Von allen Systemen, bei denen die Löslichkeit der Polymere eine PG-Bestimmung ermöglichte, ergab die Polymerisation in Substanz mit kristallinem CdCl2 den höchsten PG (ca. 20). In Versuchen mit den verschiedensten löslichen Initiatoren in verschiedenen Lösungsmitteln und über einen weiten Temperaturbereich fanden wir, daß ein PG von mehr als ca. 8 nur ganz ausnahmsweise erzielt werden konnte.Das wachsende Dialkoxycarbeniumion, \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R}\hbox{---} {\rm CH}_2 \mathop {\rm C}\limits^ \oplus \left( {{\rm OR}} \right)_2, $\end{document} kann an mindestens fünf verschiedenen Kettenabbruchreaktionen teilnehmen. und unsere Befunde erklären, wieso die Geschwindigkeit der Abbruchreaktionen so vie1 größer ist als bei anderen Olefinen.Die saure Hydrolyse der Polymere ergibt die entsprechenden Poly(1-oxoäthylene) (Poly-(1,3-diketone)) (4a, b), von deren Keto- und Enol-Formen verschiedene Derivate hergestellt wurden.
    Notes: Various ketene acetals (1a-d) were prepared and their cationic polymerization under homogeneous and heterogeneous conditions, in bulk and in solution between ca. 100 and -100°C were investigated.Most of the reaction products formed in solution were viscous pale yellow fluids or sticky red solids, whereas those formed in bulk with solid, sparsely soluble initiators were white waxes or powders. For all systems for which solubility of product permitted DP determinations, the highest DPs (ca. 20) were found from bulk polymerization with solid CdCl2. With a wide range of soluble initiators in different solvents over a wide range of concentrations, DPs greater than about 8 were exceptional.It is suggested that there are at least five chain-breaking reactions involving the growing dialkoxycarbenium ion \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R}\hbox{---} {\rm CH}_2 \hbox{---} \mathop {\rm C}\limits^ \oplus \left( {{\rm OR}} \right)_2 $\end{document} and evidence is presented which accounts for the high rate of chain-breaking compared with that for other olefinic monomers.Acid hydrolysis of the polymers yielded the corresponding poly(1-oxoethylenes) (poly-(1,3-diketone)) (4a, b), and various derivatives of both the keto and enol forms of these were prepared.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021751004
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    Fonctionalisation des polyalcadiènes: Étude sur molécules modèles des structures accessibles à partir des polymères de l'isoprène par utilisation de l'isocyanate de chlorosulfonyle (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2849-2863 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The reaction of chlorosulfonyl isocyanate (1) with alkenes permits to consider the preparation of lactames and N-chlorosulfonated amides as synthetic intermediates.With the goal to obtain functional macromolecular compounds the use of this reaction was considered for the chemical modification of polyisoprenes having a predominant 1,4- or 3,4-microstructure. With the intention to define the modifications of the microstructures caused by the action of 1 on these polymers, the reaction was studied with models.In this way it was possible to determine the percentages of the formation of lactame and N-chlorosulfonated microstructures for each type of chain arrangement in polyisoprene. On the other hand, the transformations of the N-chlorosulfonated lactames into free lactames, amino acid hydrochlorides, and unsaturated nitriles was studied.This work permits to define the spectral references of the microstructures which may be formed applying the reactions to the polymers. In addition it makes it possible to select the type of chain arrangement in polyisoprene which will lead to functional macromolecular compounds with the highest yields and the best selectivity for special applications.
    Notes: La réaction de l'isocyanate de chlorosulfonyle (1) avec les alcènes permet d'envisager la réalisation de lactames et d'amides N-chlorosulfonées qui constituent des intermédiaires de synthèse.Dans le but d'obtenir des composés macromoléculaires fonctionnels, nous avons envisagé l'utilisation de cette réaction pour la modification chimique de polyisoprènes de microstructures-1,4 ou 3,4 prédominantes. Afin de définir les modifications de microstructures provoquées par action de ce réactif, sur ces polymères, nous avons étudié la réaction envisagée sur leurs molécules modèles.Ainsi, il nous a été possible de déterminer les pourcentages de formation de microstructures lactames et amides N-chlorosulfonées pour chaque type d'enchaînements polyisopréniques. D'autre part, nous avons étudié les transformations des lactames N-chlorosulfonées en lactames libres, en hydrochlorures d'amino-acide et en nitriles insaturés.Ce travail permet de définir les références spectrales des microstructures susceptibles de se former lors de l'application aux polymères. Il nous autorise en outre à sélectionner le type d'enchaînement polyisoprénique qu'il conviendra de choisir pour conduire avec plus hauts rendements et la meilleure sélectivité aux composés macromoléculaires fonctionnels recherchés pour des applications spécifiques.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/macp.1974.021751006
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    Untersuchungen zum oxidativen Abbau nativer Cellulose, 2.1. Mitteilung: cf.2. Einfluß der Alkalibehandlung auf die Viskositäts-Molekulargewichts-Beziehungen (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2895-2902 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: For kinetic studies of cellulose degradation by molecular oxygen it is necessary to establish new [η]-M-relationships, since the treatment of cellulose by concentrated alkali solutions changes the intrinsic viscosity [η] without changing the molecular weight M. Two series of degradated celluloses treated for different times with sodium hydroxide solutions were prepared, and the constants of the Kuhn-Mark-Houwink equation were determined for cellulose nitrates in acetone and for celluloses in Cuoxam (Cu(NH3)4(OH)2) by comparison of intrinsic viscosity with light scattering data.
    Notes: Um die Kinetik des oxidativen Abbaus nativer Cellulose viskosimetrisch verfolgen zu können, müssen neue [η]-M-Eichbeziehungen aufgestellt werden, da die Behandlung der Cellulose mit konzentriertem Alkali den Staudingerindex [η] erniedrigt, ohne das Molekulargewicht M zu verändern. Es wurden zwei Reihen oxidativ abgebauter, verschieden lange mit Alkali vorbehandelter Cellulosen hergestellt und an diesen die Konstanten der Kuhn-Mark-Houwink-Gleichung für die Cellulosenitrate in Aceton und die Cellulosen in Cuoxam (Cu(NH3)4(OH)2) durch Vergleich mit Lichtstreuungsmessungen bestimmt.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/macp.1974.021751010
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    Photosensitized polymerization of butyl methacrylate under high pressure (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2903-2912 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Geschwindigkeitskonstanten des Wachstums und des Abbruchs für die Polymerisation von Butylmethacrylat wurden bei 30°C über einen Druckbereich von 1 bis 1000 bar bei 250 bar Druckintervallen gemessen. Durch Bestimmung des Druckeinflusses auf die Elementarreaktionen der Polymerisation wurden die Aktivierungsvolumina des Wachstums und des Abbruchs zu -23,2 cm3/mol bzw. 17,8 cm3/mol erhalten. Das Aktivierungsvolumen der Gesamtreaktion war -17,4 cm3/mol.Der Einfluß des Drucks auf die Geschwindigkeitskonstanten der Elementarreaktionen bei der Butylmethacrylat-Polymerisation wurde mit den Ergebnissen der Polymerisation von Methylmethacrylat verglichen. Der Vergleich zeigt, daß die größere Estergruppe eine Verminderung des Werts für das Aktivierungsvolumen mit sich bringt und daß der Einfluß des Drucks auf die Abbruchsreaktion etwas kleiner als bei der Polymerisation des Methylmethacrylats war.
    Notes: The propagation and termination rate constants for butyl methacrylate polymerization were measured at 30°C over a pressure range of 1 to 1 000 bar at a 250 bar pressure interval. By determining the effect of pressure on the individual reactions of polymerization, the activation volumes for the propagation and the termination were obtained as -23,2 cm3/mol and 17,8 cm3/mol, respectively. The overall activation volume was -17,4 cm3/mol.The effect of pressure on the individual rate constants for butyl methacrylate polymerization was compared with the results for methyl methacrylate polymerization. The comparison shows that, for the propagation reaction, the increase in the size of the ester group brings about a diminution in the value of the activation volume, and that the effect of pressure on the termination reaction was somewhat smaller than that for methyl methacrylate polymerization.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751011
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  • 189
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    Polyreaktionen in orientierten Medien, 4.3. Mitteilung: E. Perplies H. Ringsdorf und J. H. Wendorff, Makromol. Chem. 175, 533, (1974). Fotoreaktionen von Fumar- und Maleinsäurederivaten in Multischichten (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 699-700 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750230
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  • 190
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    IUPAC. 1974 Prague meetings on macromolecules. Under the sponsorship of the IUPAC, two meetings will be organized in 1974: 14th microsymposium (Prague, August 26-29, 1974):Crosslinking and networks (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 702-702 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750232
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  • 191
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    Acetoacetatgruppenhaltige Epoxidharze (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 739-748 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Epoxy resins based on 2,2-Bis(4-hydroxyphenyl)propane (bisphenol A) and 1-chloro-2,3-epoxypropane (epichlorohydrin) reacted at their secondary hydroxy groups with diketene without changing their epoxy groups. Thus, products containing epoxy groups and acetoacetate groups were obtained. The reactivity of these groups could be used in simultaneous or subsequent reactions. The reaction of the acetoacetate groups with amines leading to β-aminocrotonic acid esters, served as an example for simultaneous reactions, whereas the epoxide groups were reacted in a conventional manner. As an example for subsequent reactions the chelation of the acetoacetate groups in a first step and the subsequent reaction of the epoxide groups with amines in a second step was described.
    Notes: Epoxidharze auf der Basis von 2,2-Bis(4-hydroxyphenyl)propan (Bisphenol A) und 1-Chlor-2,3-epoxypropan (Epichlorhydrin) ließen sich an ihren sekundären OH-Gruppen ohne Beeinträchtigung der Epoxidgruppen mit Diketen umsetzen. Dadurch wurden Produkte erhalten, die Epoxidgruppen und Acetoacetatgruppen aufweisen. Von der Reaktionsfähigkeit dieser Gruppen konnte gleichzeitig und nacheinander Gebrauch gemacht werden. Als Beispiel für gleichzeitige Reaktionen diente die Umsetzung mit Aminen, die mit Acetoacetatgruppen zu β-Aminocrotonsäureestern führte, während Epoxidgruppen auf bekannte Weise reagierten. Als Beispiel für aufeinanderfolgende Reaktionen wurden die zuerst ablaufende Chelatbildung der Acetessigestergruppen und die darauf folgende Reaktion der Epoxidgruppen mit Aminen beschrieben.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750304
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  • 192
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    Polyélectrolytes optiquement actifs à hydrophobie variable, 1. Copolymères amide-acide acryliques obtenus par hydrolyse contrǒlée des (±), (+) et (-) poly[N-(sec-butyl)-N-méthyl-acrylamides] (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 775-790 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: (±), (+), and (-) poly[N-(sec-butyl)-N-methyl-acrylamides] (1) are obtained by radical polymerization of (±), (-), and (+) N-(sec-butyl)-N-methyl-acrylamides (AAM). By gradual hydrolysis in CH3COOH-HCl a series of copolymers was obtained (2); they are constituted by statistically distributed hydrophobic units derived from AAM and hydrophilic units derived from acrylic acid (AA) in different ratios as a function of the hydrolysis reaction time. Viscosity, optical rotation in methanol, solubility in various solvents, IR spectra from films and optical rotatory dispersion (ORD) have been studied as a function of the degree of conversion (τ). In order to explain the dependence of ORD and IR spectra on τ, the amid-acid hydrogen bonds were removed by methylation of COOH with diazomethane. During the neutralization of the different copolymers 2 by KOH, the increase in the ratio hydrophobic units/hydrophilic units strongly modifies the ionization behaviour of the COOH groups carried by the acrylic acid units.
    Notes: On hydrolyse progressivement en milieu acide (CH3COOH + HCl) les (±), (+) et (-) poly-[N-(sec-butyl)-N-méthylacrylamide] (1) obtenus par polymérisation radicalaire des (±), (-) et (+) N-(sec-butyl)-N-méthylacrylamides (AAM). On obtient une série de copolymeères (2) consititués de motifs hydrophobes dérivés de AAM et de motifs hydrophiles dérivés de l'acide acrylique (AA) répartis statistiquement et en proportion variable selon le temps d'hydrolyse. La viscosité, le pouvoir rotatoire dans le méthanol, la solubilité dans divers solvants, les spectres IR à l'état solide et la dispersion de la rotation optique (ORD) sont étudiés en fonction du taux d'hydrolyse. Pour interpréter l'évolution de l'ORD et des spectres IR on a supprimé les interactions H entre groupes amide et acide par méthylation de ces derniers au diazométhane. Au cours de la neutralisation des différents copolymères 2 par KOH, on constate que l'augmentation de la proportion des parties hydrophobes par rapport aux parties hydrophiles modifie fortement l'ionisation des groupes COOH des motifs monomères dérivés de l'acide acrylique.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750307
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  • 193
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    Untersuchungen zur ringöffnenden Polymerisation der 2-Imino-1,3-oxazolidine (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 843-860 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The ring-opening polymerization of 2-Imino-1,3-oxazolidines to poly(ureylenethylene)s (polyethyleneureas) was investigated. 3-Phenyl-2-phenylimino-1,3-oxazolidine (1) and acidic compounds form crystalline complexes, which initiate the polymerization of 1 only in the case of coordination of the acidic compounds with the Imino group of 1.The results of the kinetic experiments give evidence of a polymerization reaction starting without an induction period and obeying pseudo first-order kinetics. They permit also the conclusion that the rate determining reaction step is bimolecular.The results are in accordance with those found for the ring-opening reaction of iminooxazolidines with organic acids in the low molecular range.
    Notes: Es wurde die ringöffnende, zu Poly(ureylenäthylen)en (Polyäthylenharnstoffen) führende Polymerisation der 2-Imino-1,3-oxazolidine untersucht.Aus 3-Phenyl-2-phenylimino-1,3-oxazolidin (1) und sauren Verbindungen ließen sich kristalline Addukte isolieren, die aber nur dann als Initiatoren für die Polymerisation von 1 wirksam waren, wenn die saure Komponente mit dem Iminostickstoff koordiniert war.Die kinetische Untersuchung der Polymerisationsreaktion ergab, daß keine Induktionsperiode auftritt und die Reaktion nach einem Zeitgesetz pseudo 1. Ordnung verläft, was für eine bimolekulare Reaktion des geschwindigkeitsbestimmenden Schritts der Polymerisationsreaktion spricht.Diese Ergebnisse ließen sich mit denen in Einklang bringen, die für die Ringöffnungsreaktion der Iminooxazolidine mit organischen Säuren im niedermolekularen Bereich gefunden wurden.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750312
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  • 194
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    Untersuchungen zur friesschen verschiebung an hydroxybenzylphenol-derivaten (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2255-2274 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The Fries rearrangement of the acetates 2a-c, 3b, 4b, and 4d of six hydroxybenzylphenol derivatives was investigated between 40 and 70°C using AlCl3 as catalyst and nitrobenzene as solvent. Besides the expected main products of the Fries rearrangement also intermediates and products formed by side reactions were isolated by column chromatography, showing the partial saponification of ester bonds to be a probable side reaction. The migration of an acetyl group to the neighbouring phenolic unit of the same molecule could not be observed. All the compounds, including the starting substances, were characterized by their IR- and 1H-NMR-spectra.
    Notes: An den Acetaten 2a-c, 3b, 4b und 4d von sechs Hydroxybenzylphenol-Derivaten wurde die Friessche Verschiebung mit AlCl3 als Katalysator in Nitrobenzol bei Temperaturen zwischen 40 und 70°C durchgeführt. Neben den zu erwartenden Hauptprodukten der Friesschen Verschiebung konnte durch Säulenchromatographie eine Reihe von Zwischen- und Nebenprodukten isoliert werden. Daraus ging hervor, daß wahrscheinlich eine teilweise Verseifung der Acetate als Nebenreaktion stattfindet. Eine Wanderung der Acetylgruppe an den benachbarten Phenolbaustein des gleichen Moleküls konnte nicht beobachtet werden. Sämtliche Verbindungen, einschließlich der Ausgangsprodukte, wurden durch ihre IR- und 1H-NMR-Spektren charakterisiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750803
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  • 195
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    Charge-transfer complexes of poly(N-vinylcarbazole) with organic electron acceptorsDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 57-65 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(N-vinylcarbazol) und das entsprechende Monomer, N-Äthylcarbazol, reagieren als Donatoren bei Charge-Transfer-Komplex-Bildungen mit Elektronen-Akzeptoren wie 2,3,5,6-Tetracyano-1,4-dimethylen-2,5-cyclohexadien-1,4-diyliden, Tetracyanoäthylen und 2,4,5,7-Tetranitro-9-fluorenon. Die Bildungskonstanten der Charge-Transfer-Komplexe von N-Äthylcarbazol mit Elektronendonatoren besitzen höhere Werte als die des Poly(N-vinylcarbazols) mit denselben Elektronenakzeptoren. Um den Polymereffekt auf diese Bildungskonstanten aufzuklären, wurden Poly(N-vinylcarbazole), die nach zwei Polymerisationstypen dargestellt wurden, mit Hilfe der Gelpermeationschromatographie fraktioniert und die fraktionierten Polymere für die Messungen der Bildungskonstanten von Charge-Transfer-Komplexen mit verschiedenen Arten von Elektronenakzeptoren verwendet. Die Beziehung zwischen Charge-Transfer-Komplexbildung und Molekulargewicht des Polymers wird anhand der Bildungskonstante und der thermodynamischen Parameter diskutiert.
    Notes: Poly(N-vinylcarbazole) and its monomeric analog, i.e., N-ethylcarbazole, act as donors in charge-transfer complex formations with such electron acceptors as 2,3,5,6-tetracyano-1,4-dimethylene-2,5-cyclohexadien-1,4-diylidene, tetracyanoethylene and 2,4,5,7-tetranitro-9-fluorenone. The formation constants of the charge-transfer complex of N-ethylcarbazole with the electron acceptors are higher than those of poly(N-vinylcarbazole) with the same electron acceptors. In order to clarify the polymer effect on these formation constants, poly(N-vinyl carbazole)s, prepared by two types of polymerizations, are fractionated using a gel permeation chromatography technique, and the fractionated polymers are used for the measurements of the formation constants of the charge-transfer complexes with various sorts of electron acceptors. The relation between charge-transfer complex formation and molecular weight of the polymer is discussed in terms of the formation constant and the thermodynamic parameters.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750108
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  • 196
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    Studies on functional micelles, 1. Preparation of cyclic dipeptides from phenylalanine S-dodecyl esterDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 105-110 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Das Hydrochlorid des Phenylalanin-S-dodecylesters (2b) reagiert im Pyridin/Wasser bei Raumtemperatur unter Bildung von 3,6-Dibenzyl-2,5-piperazindion (3) in guten Ausbeuten. Phenylalanin-S-äthylester-hydrochlorid (2a) liefert dagegen nur geringe Ausbeuten an 3 unter denselben Bedingungen. Dieser Effekt wird mit der Annahme einer Matrix-Reaktion an der Mizellen-Oberfläche erklärt. Im Gegensatz zum S-Äthylester führt die Reaktion des S-Dodecylesters zu einem Gemisch von 2 isomeren Dioxopiperazinen.
    Notes: The hydrochloride of phenylalanine S-dodecyl ester (2b) reacts in pyridine/water at room temperature to afford 3,6-dibenzyl-2,5-piperazinedione (3) in good yields. Phenylalanine S-ethyl ester hydrochloride (2a), however, gives only small yields of 3 under the same conditions. This effect is explained with the assumption of a matrix reaction on the micelle surface. In contrast to the S-ethyl ester the reaction of the S-dodecyl ester leads to a mixture of two isomeric dioxopiperazines.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750112
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  • 197
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    Preparation of a novel polyoxime and reversible uptakes of molecular oxygen and carbon monoxide by its metal complexesDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 125-136 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Einige polymere Ketone mit der Carbonylgruppe in der Hauptkette (Äthylen-Kohlenmonoxid-Copolymere) wurden mittels C-Nitrosierung der Methylengruppe und Oximierung der Carbonylgruppen in Polyoxime übergeführt. Es wird angenommen, daß das Polyoxim hauptsachlich aus 1,2-Bis(hydroxyimino)trimethylen-Einheiten aufgebaut ist. Aus den Polyoximen und bivalenten Fe-, Co-, oder Ni-Salzen wurden polymere Metallkomplexe dargestellt, die zu einer umkehrbaren Aufnahme und Abgabe von molekularem Sauerstoff be fähigt sind. Insbesondere der Fe-Komplex kann auch Kohlenmonoxid aufnehmen und abgeben.
    Notes: Polyketones with carbonyl groups in the polymer backbone (ethylene-carbon monoxide copolymer) have been converted into a novel polyoxime by means of C-nitrosation of the methylene groups and oximation of the carbonyl groups. The polyoxime is considered to be composed largely of 1,2-bis(hydroxyimino)trimethylene units. From the polyoxime and divalent Fe-, Co-, or Ni-salts, polymeric metal chelate complexes were prepared which are capable of combining reversibly with molecular oxygen and, especially the Fe-complex, also with carbon monoxide.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750115
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  • 198
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    Photosensitized polymerization of methyl methacrylate under high pressureDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 179-185 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die mittlere Wachstumsdauer der Polymerradikale in der Substanzpolymerisation des Methylmethacrylats wurde mit der Drehscheibenmethode im Druckbereich von 1 bis 1000 kg cm - 2 bestimmt. In demselben Bereich wurde auch die Anregungsgeschwindigkeit durch Messung des Verbrauchs an N′,N′-Diphenyl-N-pikrylhydrazyl als Inhibierungsmittel bestimmt. Aus diesen beiden Messungen wurde der Druckeffekt auf die Geschwindigkeitskonstanten der Elementarreaktionen bestimmt sowie die Aktivierungsvolumina der Fortpflanzungsreaktion ( - 19,0 cm3/mol) und der Abbruchsreaktion (25,0 cm3/mol). Diese Werte wurden mit den bekannten Werten für die Polymerisation des Styrols verglichen.
    Notes: By use of rotating sector technique at high pressure, the average life times of the growing polymer radical in the bulk polymerization of methyl methacrylate was measured over the pressure range of 1 - 1000 kg/cm2 at 250 kg/cm2 pressure interval. The rates of initiation at the same pressure interval was also determined by the measurement of consumption of the inhibitor using N′,N′-diphenyl-N-picrylhydrazyl as radical scavenger. The effect of pressure on the individual rate constants for the methyl methacrylate polymerization was evaluated from both experimental results and the activation volumes of the propagation and the termination was obtained as -19,0 and 25,0 cm3/mol, respectively. Their values have been compared with those of styrene polymerization.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750119
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  • 199
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    Modellbetrachtung zur Radikalausbeute bei der radikalischen Polymerisation (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 3495-3502 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The kinetically effective radical efficiency is chemically and diffusion controlled. The proportion of each control mechanism characterizes the polymerizing system. The chemical control can be deduced from the chain initiation reaction, the diffusion control from the recombination reaction of the primary radicals. The model which is developed describes these competing reactions. The mean length of the diffusion path of the primary radicals is estimated.
    Notes: Die kinetisch wirksame Radikalausbeute ist eine chemisch und diffusionskontrollierte Größe. Der Grad der jeweiligen Kontrolle ist systemspezifisch. Die chemische Kontrolle geht hauptsächlich von der Kettenstartreaktion, die Diffusionskontrolle von der Primärradikalrekombination aus. Die entwickelte Modellvorstellung erfaßt diese konkurrierenden Einflüsse. Mittlere Diffusionswege der Primärradikale bis zu ihrer Rekombination werden abgeschätzt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751215
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  • 200
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    Influence de la solvatation préférentielle dans les réactions de greffage. Polydispersité en composition des copolymères SAN dans les résines ABS (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 3523-3529 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: ABS resins formed by copolymerization of styrene (S) and acrylonitrile (AN) in the presence of polybutadiene, consist of a mixture of SAN graft copolymer on polybutadiene and of ungrafted SAN copolymer. After separation and analysis, the AN contents of the grafted and ungrafted SAN are compared. The change of the AN contents as a function of the conversion and the concentration of polybutadiene is studied.As a consequence of the preferential solvation of polybutadiene by styrene and the initiator, the grafted SAN has a lower AN content than the non grafted SAN.At low conversions, where preferential solvation is maximum, it is also possible to show the presence of non grafted SAN which is formed in the polybutadiene coil or polybutadiene medium (“internal free SAN”). The characteristics of this “internal free SAN” are similar to those of the grafted SAN and especially its AN content is lower than that of SAN copolymer prepared under azeotropic conditions in the absence of polybutadiene.
    Notes: Par copolymérisation du styrène (S) et de l'acrylonitrile (AN) en présence de polybutadiène, conduisant aux résines ABS, il se forme du copolymère greffé et du SAN libre. Après séparation et analyse du copolymère greffé, on compare la teneur en AN du SAN greffé et du SAN libre.On étudie l'évolution de ces teneurs en fonction du taux de conversion et pour différentes concentrations en polybutadiène.En raison de la solvatation préférentielle du polybutadiène par le styrène et le promoteur, le SAN greffé a une teneur en AN inférieure à celle du SAN libre.Aux faibles taux de conversion, lorsque la solvatation préférentielle est maximum, on peut également mettre en évidence du «SAN libre interne», se formant dans le milieu polybutadiène, et dont les caractéristiques sont similaires à celles du SAN greffé. Ce «SAN libre interne» présente notamment un taux en AN plus faible que les copolymères SAN préparés dans des conditions azéotropes en absence de polybutadiène.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751217
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