Kinetic solvent isotope effects and correlations of rates of solvolyses for α-methylthio and other substituted acetyl chlorides

摘要

Kinetic data for solvolyses of α-methylthioacetyl chloride, phenylthioacetyl chloride and thiophene-2-acetyl chloridenin at least 33 aqueous solvent systems including 2,2,2-trifluoroethanol–ethanol solvent were determined at 10 u0001C byna conductimetric method, and their rates of solvolyses were correlated using Grunwald–Winstein type equationsnwith the ionizing power parameter (YCln: based on the solvolyses of 1-adamantyl chloride) and the nucleophilicitynparameter (NT). Kinetic solvent isotope effects (KSIEs) in water and methanol were investigated for the abovencompounds and in methanol also for phenyl, diphenyl, and trimethylacetyl and isobutyryl chlorides. The results shownsimilar absolute rate constants, similar large amounts of nucleophilic solvent assistance, but different KSIE valuesn(explained by general base catalysis).