Electronic states of N,N '-bis(4 '-aminophenyl)-1,4-quinonediimine: comparison of results from ab initio calculations with electronic spectra

Ab initio molecular orbital calculations on various redox forms of the titl e compound, an amine-capped trimer of aniline, have been used to characteri ze the electronic states responsible for the electronic spectra and observe d redox chemistries. These data are important for understanding the electro nic structure and applications chemistry of aniline-based materials, includ ing the oligo- and poly-anilines. Ail calculations were done using hybrid H artree-Fock/density functional theory and configuration interaction with si ngle substitutions (CI-S). The computed transition energies compare well wi th those observed in the visible and ultraviolet spectra of multiple redox forms of the title compound. The high accuracy of these calculations and co rrespondence between states of the amine-capped trimer and polyaniline sugg est that the electronic chromophore of polyaniline may be a small aniline o ligomer. (C) 2000 Elsevier Science B.V. All rights reserved.