Browsing by Author "Gold, Victor"

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Heterogeneous Acid-base Catalysis: Part 1.—Catalysis of the Hydrolysis of Acetaldehyde Dimethyl Acetal (1,1-Dimethoxyethane) by Methacrylic Acid-divinylbenzene Copolymer (a weak-acid ion-exchange resin), and the characterisation of Polymer Catalysts
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (07), 1977) Gold, Victor; Liddiard, Colin J
The hydrolysis of 1,1-dimethoxyclhane is catalysed by the weak-acid ton exchange resin methacrylic acid-divinylbenzene copolymer (Zerolit SRC 41). The kinetic results for catalysis by rcsin buffer systems are analysed in terms of the two-phase model for rcsin catalysis. The rate enhancement by added polymer acid is due entirely to hydrogen ions, mainly those within the gel phase of the resin.
Heterogeneous Acid-base Catalysis: Part 2—Catalysis of the Hydrolysis of Ethyl Vinyl Ether (ethoxyethene) by Methacrylic Acid-divinylbenzene Copolymer Weak-acid Ion Exchange Resins
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (07), 1977) Gold, Victor; Liddiard, Cohn J.
Methacrylic acid-divinylbenzene copolymer is a more powerful catalyst for the hydrolysis of ethyl vinyl ether than for the hydrolysis of dimethyl acetal. Comparison of the reactions indicates that for ethyl vinyl ether catalysis by undissociated carboxylic acid groups on the resin is the predominant effect. The variation of the observed catalytic constant with the degree of neutralisation of the resin is shown to be explicable on the assumption that carboxylic acid groups flanked by two undissociated carboxylic acid groups have a higher acidity and catalytic activity than those flanked by one or two (ionised) carboxylate groups. The corresponding local dissociation quotients are evaluated from titration curves by a simple application of the transfer matrix method for a chain. The entire kinetic analysis is based on the simple two-phase model of catalysis, but there are indications that gel diffusion effects may not be entirely absent in the case of this reaction
Kinetics of Hydrogen Isotope Exchange Reactions: Part 24.—Exchange between Benzene and Water Initiated by Photolysis of Potassium Iodide Solutions
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Gold, Victor; Major, Michael A.; Gregory, Maurice J.
The action of light (253.7 nm) on solutions of potassium iodide and benzene in acidified tritium- containing water is shown to lead to tritium uptake by benzene. Systematic investigation of the exchange leads to the conclusion that the exchange is induced by hydrogen (tritium) atoms which are generated in the system by reaction of solvated electrons with hydrogen ions, the electrons being produced from iodide ions on light absorption.
Kinetics of hydrogen isotope-exchange reactions: Part 25- pH-Dependence of aromatic exchange initiated by photolysis of aqueous potassium iodide solutions
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Gold, Victor; Major, Michael A.
The aromatic tritium exchange reaction brought about by the action of light on iodide solutions containing tracer tritium and dissolved benzene is shown to depend on the acidity of the solution, falling off to a lower value at high pH. This behaviour is consistent with the existence of two exchange routes, one initiated by hydrogen(tritium) atoms and one by solvated electrons. The latter route assumes prominence only when insufficient hydrogen ions are present to compete effectively with benzene for solvated electrons. The effect of added nitrous oxide and nitrate ions is quantitatively consistent with the action of these species as electron scavengers.