Ebulliometric and spectroscopic kinetic studies on the reaction between tetracyanoethylene and NN-dimethylaniline

Abstract

The equilibrium constant for the 1 :1 charge-transfer complex between NN-dimethylaniline (DMN) and tetracyanoethylene (TCNE) in dichloromethane has been determiend by Benesi–Hildebrand and equimolar methods. The second-order rate constants, k₂, for the DMN–TCNE reaction increase with increasing amine concentration. This suggests that the charg-transfer complex is an intermediate in the reaction sequence and the rate constant, k_c, corrected on the basis of this mechanism does not vary with concentration. The Arrhenius plot, using the k_c values obtained from the three experimental methods, is a good straight line. Evidence is also presented for the reversibility of the charge-transfer complex →σ-complex step.