EXCITED-STATE LOCALIZATION OR DELOCALIZATION IN C-3-SYMMETRICAL AMINO-SUBSTITUTED TRIPHENYLBENZENE DERIVATIVES

The site-to-site intramolecular excitation transfer and excitation tra pping on one site in amino-substituted triphenylbenzene derivatives, w hich are characterized by a 3-fold symmetry, have been studied by fluo rescence spectroscopy and time-resolved microwave conductivity (TRMC). The importance of dipole relaxation due to intramolecular energy tran sfer has been demonstrated in the interpretation of the limiting aniso tropy on one hand and the change of the dipole moment and polarizabili ty upon excitation on the other hand. The interpretation of the experi mental results is based on the comparison of the molecules with C-3-sy mmetry with biphenyl model compounds.