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  • 1
    Electronic Resource
    Electronic Resource
    Hydrogen bonding in long chains of hydrogen fluoride and long chains and large clusters of water molecules (1974)
    Springer
    Theoretical chemistry accounts 34 (1974), S. 115-127 
    Details
    ISSN: 1432-2234
    Keywords: (HF)n-chains ; (H2O)n-chains ; Hydrogen bond energies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Energy band structures of one-dimensional (HF)n- and (H2O)n-chains have been calculated (1) by extrapolation of CNDO/2-MO levels to infinite chain length and (2) by the CNDO/2 crystal orbital (CO) method. In the CO-calculations interactions up to fifth neighbours have been taken into account. Both types of calculations were performed using experimental geometries and CNDO/2 minimum geometries of the corresponding dimers (HF)2 and (H2O)2. With the same geometries CO calculations on two-dimensional sheets of hydrogen bonded chains were performed too. Due to end-effects the extrapolated MO bands are much broader than the bands obtained by the CO method. In the CO calculations further neighbour interactions play a non-negligible role and hence the nearest neighbour approximation is not sufficient for an accurate description of crystals containing hydrogen bonds. MO calculations on one-dimensional chains of both systems show that the hydrogen bond energies increase with the number of monomers indicating the presence of cooperative effects. The hydrogen bond energies calculated with the CO method are usually somewhat larger than those extrapolated from the MO results. In three-dimensional networks of (H2O)n, however, the additional stabilization of clusters with respect to dimers is drastically diminished.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00551362
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  • 2
    Electronic Resource
    Electronic Resource
    Theoretical investigation of semiconductive properties in proteins. I. Electrical conductivity, charge carrier mobilities, and free paths in β-polyglycine (1974)
    New York : Wiley-Blackwell
    Biopolymers 13 (1974), S. 1731-1737 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Theoretical values are reported for the specific conductivity, charge carrier mobilities, and delocalized free paths in β-polyglycine using the parallel-chain pleated sheet conformation and the all-valence electron energy band structure obtained previously. The mobilities are found to be much larger along the polypeptide backbones than in the direction of the hydrogen bonds. This indicates a mechanism of conduction in which the former path is favored for electronic delocalization. The preexponential factor of the specific conductivity obtained theoretically agrees well with experimental results.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1974.360130905
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Energy bands and electronic delocalization in the sugar-phosphate backbone of DNA (1974)
    New York : Wiley-Blackwell
    Biopolymers 13 (1974), S. 1739-1745 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The results of a CNDO/2 all-valence electron crystal orbital study are reported for the sugar-phosphate chain of DNA. The valence and conduction bandwidths are found to be large enough to make electronic delocalization through this backbone possible. Different mechanisms for charge carrier transport in DNA are compared on the basis of the electron and hole effective masses. Conduction along the backbone seems to be at least as probable as through the aperiodic system of the superimposed nucleotide bases.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1974.360130906
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    Paper (German National Licenses)
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