QUANTUM-CHEMICAL MODELING OF ELECTRONIC CHARGE-DENSITY DISTRIBUTION IN SEVERAL TETRATHIAFULVALENE DERIVATIVES

We have calculated electronic charge density distributions for typical representatives of tetrathiafulvalene derivatives. We have applied a combined semi-empirical and ab initio method to perform these calculat ions because of complexity of the mentioned molecules. Our calculation s have unambiguously shown an essential influence of backbone aromatic group modifications on distribution of electronic charge density grad ients. Moreover, we have observed a substantial change of the charge d ensity gradients under influence of benzene ring modifications that le ads to a strong non-uniformity of the electronic charge density distri butions. It was shown that the main density change was observed on the opposite (with respect to the structural modification) end of a given molecule. (C) 1997 Elsevier Science S.A.