E. A. Abu-Gharib, R. El‐Khatib, L. A. E. Nassr
Feb 1, 2017
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Influential Citations
16
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Journal
Arabian Journal of Chemistry
Abstract
Base-catalyzed hydrolysis of coumalic acid (COU) in binary aqueous-methanol and aqueous-acetone mixtures has been studied kinetically at a temperature range from 283 to 313 K. Moreover, the change in the activation energy barrier of COU from water to water-methanol and water-acetone mixtures is estimated from the kinetic data. Solvent effects on reactivity trends have been analyzed into initial and transition state components by using transfer chemical poten- tials of the reactants and kinetic data. The transfer chemical potentials dml h for COUanion are derived from solubility data from its calcium, cerium and lanthanum salts. The decrease in rate con- stant of the base hydrolysis reaction of COU as the percentage of methanol or acetone increases is dominated by transition state (TS). The base hydrolysis reaction of COU follows a rate law with kobs = k2(OH � ) and the reaction mechanism was suggested. The high negative values of entropy of activation support the proposal mechanism, i.e. the investigated reaction takes place via the for- mation of an intermediate complex. Thus, the ring opening of the intermediate complex would be the rate controlling step.