NEAR-ULTRAVIOLET ELECTRONIC-TRANSITIONS OF THE TRYPTOPHAN CHROMOPHORE - LINEAR DICHROISM, FLUORESCENCE ANISOTROPY, AND MAGNETIC CIRCULAR-DICHROISM SPECTRA OF SOME INDOLE-DERIVATIVES

Moment directions and intensities of the two lowest electronic transitions of indole are important in many contexts but have been subject to controversy. We have measured UV and IR linear dichroism on indole, 5-methylindole, 5-methoxyindole, and 3-methylindole in an anisotropic polyethylene host and determined the transition moment directions and intensity profiles of the lowest, nearly degenerate transitions 1 L a ← 1 A 1 and 1 Lb← 1 A 1 . An ambiguity due to the two possible solutions for each transition moment angle can be removed by considering the effects of the changed alignment of the substituted indoles