A Self-Consistent-Field Study of Tryptophan

The aromatic amino acid, tryptophan, was studied with the semiempirical self-consistent-field method. Ground-state bond lengths and π-election charge densities as well as the energies and transition moment directions for the first three absorption transitions were calculated. Published experimental work indicates that the indole part of tryptophan may enter into excited state interactions with neighboring solvent molecules; since this interaction will lead to emissive properties different from those of absorption, the present work includes a calculation of the transition moment direction for light emission by tryptophan