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  • 1975-1979  (2)
  • 1977  (1)
  • 1976  (1)
  • Analytical Chemistry and Spectroscopy  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 8 (1976), S. 489-499 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Finite perturbation calculations using CNDO/2 wave functions are presented for the determination of 31P—13C and 31P—1H couplings. The calculations were carried out on 46 molecules and a comparison with experimental values is given. The groups of compounds considered were phosphonium cations, phosphine oxides, alkylidenephosphoranes, phosphine sulfides, phosphoranes and phosphines. With the exception of phosphines, the finite perturbation approach reproduces the experimental couplings with fair accuracy. It is found that there is a good correlation with the calculated 1J(P, C) and the phosphorus 3s-carbon 2s bond orders for tetra- and pentavalent phosphorus compounds. This lends support to the growing body of evidence for the direct relationship of the magnitude of 1J(P, C) and percent s character in the hybrid orbital on the carbon comprising the P—C bond. The finite perturbation technique was also used to explore the effects of geometrical changes on P—C and P—H couplings. Finally, the effect of deleting d orbitals on phosphorus is discussed briefly.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 9 (1977), S. 75-79 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 13C and 15N n.m.r. results for a series of diazo compounds are reported. It is found that the diazo carbon is shielded by an extraordinary amount compared with normal sp2 hybridized carbons. The 15N chemical shifts reveal that the terminal nitrogen is deshielded relative to the central one. This is contrary to that expected from charge effects but support is found for this phenomenon in other systems. One-bond 13C—14N coupling in diazomethane is also reported for the first time. INDO MO calculations of the charges and finite perturbation calculations of 13C—14N and C—H couplings are compared with the experimental results.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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