The kinetics of formation of electron donor–acceptor complexes. A temperature-jump study

Abstract

The kinetics of the Electron Donor–Acceptor (EDA) complex between N,N,N′,N′-tetramethyl-p-phenylenediamine and m-dinitrobenzene in acetonitrile has been studied by the temperature-jump technique. The magnitude of the rate constants of association and dissociation, although relatively large, is well below the diffusion control values. The calculated rates closely coincide with those obtained by chronoamperometry. An entropy control is suggested for this reaction. The results obtained in this work are useful to demonstrate that the concept about EDA complexes being formed by diffusion-controlled reactions should not be generalized. Keywords: electron donor–acceptor complexes, m-dinitrobenzene, N,N,N′,N′-tetramethyl-p-phenylenediamine, T-jump, kinetics.