Kinetic isotope effects and aliphatic diazo-compounds. Part V. Secondary isotope effects in general acid catalysis

Abstract

Data are reported for the secondary isotope effect on the reaction of 3-diazobutan-2-one with CL₃CO₂H and LCO₂H. The data obtained by the differential method are accurate enough to determine an isotopic α_HA from the relationship (k_D/K_H)=(K_D/K_H)^α_HA. The isotope substitution differentiates the Brønsted plot and the values of α_HA agree with the α_B found from the conventional Brønsted plot for the carboxylic acids.