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  • 1
    Electronic Resource
    Electronic Resource
    An intermolecular perturbation approach to hydrogen bondings in systems in the ground and excited electronic states (1974)
    Springer
    Theoretical chemistry accounts 35 (1974), S. 217-230 
    Details
    ISSN: 1432-2234
    Keywords: Intermolecular perturbation ; Hydrogen bond ; Energy partitioning ; Spectral shifts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The intermolecular interaction energy for binary systems in the ground and excited electronic states was partitioned into the Coulomb, exchange-repulsion, induction, dispersion and charge-transfer interaction terms by the perturbation expansion method. The various interaction terms were evaluated for the hydrogen bondings in (HF)2, (H2O)2, (CH3OH)2, (RCOOH)2, and HF·H2O in various geometrical configurations. It has been found that the Coulombic interaction plays a dominant role in the stability of these hydrogen bonded systems. The method was further applied to the HCOOH·H2O codimer in both the ground and excited singlet electronic states. The results were in accord with the well-known water solvent effects on the shifts of absorption spectral bands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00546906
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  • 2
    Electronic Resource
    Electronic Resource
    Equilibrium and kinetic studies of reactions of 2-methyl-2-propanesulfenic acidDedicated to Prof. Yao-Zeng Huang on the occasion of his eightieth birthday. (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Heteroatom Chemistry 3 (1992), S. 577-583 
    Details
    ISSN: 1042-7163
    Keywords: Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Methyl-2-propanesulfenic acid readily undergoes self-condensation to give S-t-butyl 2-methyl-2-propane-thiosufinate. Rates of the reaction were measured in aqueous acetonitrile solution by use of NMR and UV spectroscopy. The reaction is second order in the substrate. The half-life in a neutral aqueous solution is about 150 hours at 35°C when the initial substrate concentration is 0.003 M. The rate is proportional to acid concentration in the range 0.004-0.2 M. In alkaline solution, the main reaction is self-condensation but some side reactions also seem to occur. The disappearance of the substrate does not follow satisfactory second-order kinetics, but the second-order rate constants obtained by the time-lag method show a maximum around pH 10-11. The pKa (10.47) of the sulfenic acid was obtained at 14°C from a sig-moid curve of the initial absorbances (240 nm) determined by extrapolation of the time-dependent curve.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hc.520030520
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  • 3
    Electronic Resource
    Electronic Resource
    Oxygen-18 labeling of cyclic and acyclic sulfinate estersThis paper is dedicated to Prof. James Cullen Martin on the occasion of his sixty-fifth birthday. (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Heteroatom Chemistry 4 (1993), S. 223-228 
    Details
    ISSN: 1042-7163
    Keywords: Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Both cyclic and acyclic sulfinate esters were labeled with 18O at the sulfinyl oxygen by acid-catalyzed isotope exchange with H218O or alkaline hydrolysis in H218O followed by re-esterification. Long-range 18O isotope effects on the 13C NMR chemical shifts were observed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hc.520040216
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  • 4
    Electronic Resource
    Electronic Resource
    Quaternary anilinium salt as an initiator for vinyl polymerization (1955)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 15 (1955), S. 594-595 
    Details
    ISSN: 0022-3832
    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/pol.1955.120158027
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  • 5
    Electronic Resource
    Electronic Resource
    Catalytic reactivity of organometallic, compounds for olefin polymerization. I. Diethylcadmium and other related compounds (1959)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 30 (1959), S. 109-122 
    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: Diäthylcadmium löst in Gegenwart einiger Sauerstoffverbindungen die Vinylpolymerisation aus. Die Copolymerisation von Styrol und Methacrylsäuremethylester mit Diäthylcadmium liefert Copolymere mit den gleichen Einbauverhältnissen wie im Fall einertypischen Radikalkettencopolymerisation. Dieses Ergebnis bedeutet, daß die Wachstumsreaktion der hier beschriebenen Polymerisation nach einem Radikalmechanismus verläuft.Benzoehinon und Hydrochinon haben, wenn sie in geeigneten Mengen verwendet werden, eine beschleunigende Wirkung auf die Polymerisation. Ein möglicher Mechanismus für die Wirkung des Chinons und Hydrochinons wird aufgezeigt. Vergleichende Polymerisationsversuche mit den Äthylderivaten des Zink, Aluminium und Antimon zeigen, daß auch sie nach einem Radikalmechanismus verlaufen.Schließlich wird, in Analogie zum ZIEGLER-Katalysator, das Verhalten eines Gemisches von Diäthylcadmium und Titantetrachlorid im Molverhältnis 4 : 1 an verschiedenen Vinylmonomeren untersucht.
    Notes: Diethylcadmium induces vinyl polymerization in the presence of some oxygen compounds. Copolymerization between styrene and methyl methacrylate using diethylcadmium resulted in the formation of copolymers having the same composition as those from the typical radical copolymerization. These results suggest at least the propagation stage of the present polymerization to proceed according to the radical mechanism. However, benzoquinone or hydroquinone in an appropriate quantity was found to be an effective co-catalyst toward this polymerization. A possible mechanism for this is advanced. Comparative study of polymerizations with ethyl derivatives of zinc, aluminium and antimony has revealed that these polymerizations are also radical type in character. Finally, in connection with the ZIEGLER-catalyst, the behavior of the mixture of diethylcadmium and titanium tetrachloride (4 : 1 in mole ratio) toward various vinyl monomers is exatnined.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1959.020300108
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  • 6
    Electronic Resource
    Electronic Resource
    Co-catalytic action of quinones and phenols in methyl methacrylate polymerization by diethylcadmium (1958)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 31 (1958), S. 247-249 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1958.1203112251
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  • 7
    Electronic Resource
    Electronic Resource
    Quaternary ammonium salt as initiator for vinyl polymerization (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 36 (1959), S. 407-420 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Binary mixtures of amines and alkyl (or aralkyl) chlorides were used as the initiators for the polymerizations of several acrylic monomers and styrene. A parallelism was found between the catalytic actions of the mixtures and their quaternary salt formations. Comparative experiments showed that the preformed quaternary ammonium salts were superior catalysts to the corresponding binary mixtures. The inhibitory action of hydroquinone on the polymerization and the composition of a copolymer of methyl methacrylate and styrene suggested that the vinyl polymerizations initiated by ammonium salts were free radical reactions. An equimolar mixture of benzyl chloride and N,N-dimethylaniline gave, when refluxed for ten hours, N-methyl-N-benzylaniline and N,N-dibenzylaniline. Thus, it was suggested that the binary mixtures would first form the ammonium salts, followed by decomposition to give a radical which initiated the radical polymerizations of vinyl monomers.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203613034
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  • 8
    Electronic Resource
    Electronic Resource
    Molecular orbital considerations on the reactivities of vinyl compounds. II. Ionic polymerizability (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 40 (1959), S. 499-510 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The β-carbon localization energies Lβ+ and Lβ- for electrophilic and nucleophilic additions to vinyl compounds, respectively, were calculated according to the simple LCAO MO method and were compared with the experimental results so far reported on the ionic polymerizability of these compounds. The larger the cationic (or anionic) polymerizability of a monomer, the smaller was the value of Lβ+ (or Lβ-) for it. It was also verified in terms of localization energies that the vinyl monomers which are not amenable to radical polymerization tend to polymerize more easily by either of the two ionic mechanisms. By applying Jaffé's first order perturbation method, Lβ+ and Lβ- of each monomer were expressed as functions of the Coulomb integral parameters of the heteroatoms involved. Although the values of Lβ+ and Lβ- did not agree perfectly with the direct results obtained from secular equations, the discrepancy in both cases could be minimized when each of the Coulomb integral parameters employed in the perturbation approximation was empirically taken as 0.6 times as large as that used in the direct variation calculation. The procedure was successfully applied to the interpretation of the substituent effect on the cationic polymerizability of styrene.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1204013718
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  • 9
    Electronic Resource
    Electronic Resource
    Molecular orbital considerations on the reactivities of vinyl compounds. III. Polarographic reduction (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 40 (1959), S. 511-519 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polarographic half-wave reduction potentials E1/2 of several vinyl (including vinylidene) monomers were measured and were discussed on the basis of the molecular orbital theory. The current-voltage curves were determined in a 0.05 M solution of tetra-n-butylammonium iodide in the mixture of dioxane and water (3:1 by volume). The values of E1/2 were read against the saturated calomel electrode. It was found that E1/2 is correlated with xiv by E1/2 = 2.33 xiv-0.80, where xiv stands for the root of the MO secular equation for the π-electronic system of the vinyl monomer corresponding to the lowest vacant level. Some of the monomers could not be reduced in the range of the applied potential less negative than - 3.0 volt vs. SCE, which was reasonably explained by their relatively large values of -xiv. It was suggested that the polarographic reducibility of vinyl monomers is roughly parallel to their anionic polymerizability. Furthermore, the lowest vacant π-orbital energies of vinyl compounds were calculated according to the first order perturbation method. The results obtained thus were in good accordance with those calculated directly from the secular equations. It was also shown that the first ionization potentials of vinyl compounds were roughly related to their highest occupied π-electronic energies.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1204013719
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  • 10
    Electronic Resource
    Electronic Resource
    Ionic properties of the triethylaluminum and stannic cloride system as stereospecific polymerization catalyst for vinyl isobutyl etherPresented at the 16th Annual Meeting of the Chemical Society of Japan (Tokyo, April, 1963). (1964)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 76 (1964), S. 209-229 
    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 des Vinylisobutyläthers wurde mit Aluminiumtriäthyl und Zinntetrachlorid als Katalysatorsystem untersucht. Der mit äquimolekularen Mengen von Aluminiumtriäthyl und Zinntetrachlorid erhaltene Polyvinylisobutyläther zeigte die höchste Isotaktizität.Aus Messungen der Reaktionswärme von Aluminiumtriäthyl mit Zinntetrachlorid und aus der Analyse der bei der Hydrolyse dieses katalytischen Systems entwickelten Gase geht hervor, daß aus Aluminiumtriäthyl und Zinntetrachlorid sich Aluminiumchlorid und Triäthylzinnchlorid bilden. Kryoskopische Messungen und NMR-Untersuchungen zeigen klar, daß Triäthylzinnchlorid und Aluminiumchlorid in Benzol assoziiert sind. Überdies zeigt das 1:1-Gemisch von Aluminiumtriäthyl und Zinntetrachlorid eine bemerkenswert hohe Leitfähigkeit sogar in unpolaren Lösungsmitteln wie Toluol. Bei der Elektrolyse dieses katalytischen Systems in Toluol wurden sowohl Aluminium- als auch Zinn-Verbin-dungen an den Elektroden abgeschieden. Daraus wurde auf die Bildung multipler Ionen wie \documentclass{article}\pagestyle{empty}\begin{document}$$ ({\rm Et}_{\rm 3} {\rm Sn}^ + \cdots - {\rm AlCl}_4 )_{\rm n} {\rm Et}_3 {\rm Sn}^ + {\rm and }( - {\rm AlCl}_4 \cdots {\rm Et}_3 {\rm Sn}^ + )_{\rm n} - {\rm AlCl}_4, $$\end{document} geschlossen, die in Übereinstimmung stehen mit dem Mehrzentrenkatalysator der stereo-regulären Polymerisation, den wir früher vorschlugen.
    Notes: Polymerization of vinyl isobutyl ether was investigated with the catalytic system triethylaluminum and stannic chloride. The poly(vinyl isobutyl ether) obtained with an equimolar mixture of triethylaluminum and stannic chloride possessed the highest isotacticity.Measurement of the heat of reaction between triethylaluminum and stannic chloride and determination of the gas evolved on hydrolysis of this catalytic system showed that the reaction product of an equimolar amount of triethylaluminum and stannic chloride is an equimolar mixture of aluminum chloride and triethyltin chloride. Cryoscopic measurements and NMR studies indicated definitely that aluminum chloride and triethyltin chloride are highly associated in benzene. Furthermore, the 1:1-mixture of triethylaluminum and stannic chloride exhibited remarkably high electric conductivity even in a non-polar solvent like toluene. In the electrolysis of this catalytic system in toluene, both aluminum and tin compounds were deposited at both electrodes.These results lead us to the concept of the formation of multiple ions such as \documentclass{article}\pagestyle{empty}\begin{document}$$ ({\rm Et}_{\rm 3} {\rm Sn}^ + \cdots - {\rm AlCl}_4 )_{\rm n} {\rm Et}_3 {\rm Sn}^ + {\rm and }( - {\rm AlCl}_4 \cdots {\rm Et}_3 {\rm Sn}^ + )_{\rm n} - {\rm AlCl}_4, $$\end{document} in favor of the hypothesis of the multi-center catalyst in stereoregular polymerization, previously proposed by us.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1964.020760118
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