by See-wing Chiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 64-65.

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Thesis (Ph.D.)--Case Western Reserve University, 2009 / Abstract Department of Mechanical and Aerospace Engineering Title from PDF (viewed on 14 April 2009) Available online via the OhioLINK ETD Center

Thesis (Ph. D.)--Johns Hopkins University, 1925. / Biography.

The kinetic study of the reactions, of the ethyl radical with the conjugated olefinic compounds has revealed the effect of various structual factors upon molecular reactivity. Acrylohitriie and its mono-methyl derivatives; cis- and trans-crotononitrile and methacrylonitrile were the substrates in this investigation. It was found that the addition of the ethyl radical to the C=C double bond was the most important reaction and that methathesis and addition to the CN triple bond could be neglected. Values for the energy of activation (E₇-½E₂) for cis- and trans-crotononitrile and methacrylonitrile were not distinguishable; 4.85 ±0.68, 4.69 ±0.96 and 4.61 ±0.67 respectively. The energy of activation for acrylonitrile for acrylonitrile was found to be 3.45 ±0.52. It appeared that the methyl group In cis- and trans-orotononitrile and in methacrylonitrile raised the energy of activation for addition from the value for acrylonitrile by about the same amount for each of the methyl derivatives. Simple correlations of the rate constants for the addition of the ethyl radical with the methyl affinities with various substrates, and with the monomer reactivity ratios for the copolymerization of various monomers with styrene were obtained. Copolymerizatlon reactions of cis- and trans-crotononitrile with styrene are also investigated and the polimerizability of these compounds is discussed. Some studies on the isomerization of cis- and trans- crotononitrile are also discussed. In this work, cis-croto-nonitrile was found to be thermally more stable than the trans isomer. / Science, Faculty of / Chemistry, Department of / Graduate

[No abstract available] / Science, Faculty of / Chemistry, Department of / Graduate

[No abstract available] / Science, Faculty of / Chemistry, Department of / Graduate

A kinetic survey of the reactions of the ethyl radical with conjugated cyclic defines and related compounds has revealed a great variety of reactivity with respect both to addition and metathesis. An attempt to correlate reactivity with molecular structure has been presented both in the language of polymerization kinetics and of molecular orbital theory. In particular, the correlation of the energy of activation for the addition reaction with free valence and with localization energy has been pursued with some measure of success. The results of this survey indicate that characteristic values exist for the weighted A factors of both the addition and metathetical reactions. If the measured A factor is divided by the number of equivalent most-reactive sites in the molecule, values of the quotient lie within a narrow range. A characteristic value of this quotient appears to be common to molecules of diverse structural types. The results of this survey closely parallel the results of other investigators in related fields. In particular, rate constants for the addition of the ethyl radical in the gas phase are linearly related to rate constants for the addition of the methyl and the poly-styryl radical in solution. The few deviations observed in the comparison with the polyvinyl acetate and the polyacrylonitrile radicals may be explained in terms of polar effects by reference to the general equations for radical reactivity proposed by Bamford, Jenkins and Johnston and by Schwan and Price. The significance of the ratio of rate constants for addition and metathesis of a given compound with the ethyl radical has been considered as an index for reactivity in homopolymerization. The values of the ratio accord well with the published data on the degree of polymerization of these compounds. Finally the kinetic measurements have provided further information on certain special topics including the reactions of the cyclohexadienyl radical, the electron affinity of cyclooctatetraene and the structure of cycloheptatriene. / Science, Faculty of / Chemistry, Department of / Graduate