Nucleophilic Substitution at a Carbonyl Carbon Atom (). Kinetic Studies on the Sovolysis of 2-Thenoyl Chloride in Binary Mixtures of Acetone-Water and Ethanol-Water

摘要

The rates of solvolysis for 2-thenoyl chloride have been measured in aqueous acetone and aqueous ethanol at various temperatures ranging from 20 to 40?é. The activation parameters and the Grundwald-Winstein's slope are determined by the analysis of solvolysis rates. The results indicated that the reaction rates of solvolysis are considerably slower than those of the reaction for benzoyl chloride due to the electron donating effect of thiophene nucleus. The results also showed that the reaction proceeds with the SN1 mechanism in water-rich solvents whereas the SN2 character increases with the decrease of water content, and overall reaction is subject to entropy control.