Abstract
Interaction of some thiazole and benzothiazole derivatives as donors with certain di- and trinitrobenzene derivatives as acceptors results in the formation of 1:1 molecular species. The infrared, NMR and ultraviolet analysis of the complexes with non-acidic acceptors reveals the presence of π-π* interaction from a HOMO of the thiazole nucleus or the phenyl moiety of the benzothiazoles to a LUMO of the benzene ring of the acceptors. The existence of this type of interaction is supported by HMO calculations on the donor molecules. On the other hand, the molecular complexes derived from acidic acceptors are stabilized, in addition to the π-π* interaction, by proton transfer from the hydroxyl or carboxylic group of the acceptor to the amino group of the aminothiazole donors. The ionization potentials of donors, electron affinities of acceptors as well as the energy of the CT complexes were computed from their u.v. and visible spectra.