Spectroscopic and kinetic studies on the electron donor-acceptor interaction between a series of methylated anilines and naphthalene-1,4,5,8- tetracarboxylic dianhydride

Abstract

The electron donor-acceptor (EDA) interaction between naphthalene-1,4,5,8-tetracarboxy1ic dianhydride and a series of methylated anilines has been studied in carbon tetrachloride medium. It is found that the N-substituted anilines form stable 1:1 EDA complexes while those with free -NH₂ group form 2(donor) : 1(acceptor) EDA complexes which decay by a mechanism first order with respect to the complex but zero order with respect to both acceptor and donor. The trend in the charge transfer transition energies of the complexes has been rationalised by a comparison with the CT bands of EDA complexes of the same anilines with tetracyanoethylene and a PMO calculation on the anilines. A perturbational Huckel parameter h_Me has been found from this trend and its value, - 0.4, is in close agreement with Streitwieser's recommended value (-0.5).