Browsing by Author "Homer, John"

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    Molecular Complexes: Part 11.'—Sonic Comments on Electrostatic and Steric Effects in the Formation of Acrylonitrile + Aromatic Complexes
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Homer, John; Yadava, Raja R.
    The interactions between acrylonitrile and various alkylbenzenes have been studied by 1H n.m.r. at several temperatures. The equilibrium quotients, Kx, and aromatic induced shifts, Δc, at a particular temperature, as well as ΔG°, ΔH° and ΔS° appear superficially to show an almost random variation with the degree of alkylation of the aromatic nucleus. However, the data have been rationalized in a quantitative fashion by considering that the reaction and complex parameters are governed by three factors. These are due to an intermolecular electrostatic effect and two steric features of the aromatic compounds due to the “blocking” and “trapping” effects of the alkyl substituents.
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    Molecular Complexes: Part 12- Use of Phase Distribution and Nuclear Magnetic Resonance Methods to Elucidate the Mechanism of the Acetone + Benzene Reaction
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Homer, John; Cooke, Melvyn C.
    The results of studies of the acetone+benzene interaction obtained from a phase distribution technique and the conventional n.m.r. approach are compared. This reveals that the conventional n.m.r. approach to studies of molecular complexes can be misleading. In resolving the inherent problems a mechanism for the acetone + benzene reaction is proposed. The reaction is studied in the presence of carbon tetrachloride and cyclohexane separately. It is shown that whereas carbon tetrachloride is reactive towards benzene, cyclohexane is less so and that data obtained by both experimental techniques using this material as solvent provide values for the equilibrium quotient, Kx, and aromatic induced shift, Ac, which are in good agreement.