HIGH-PRESSURE STUDIES OF THE VISCOSITY EFFECTS ON THE FORMATION OF THE TWISTED INTRAMOLECULAR CHARGE-TRANSFER (TICT) STATE IN 4,4'-DIAMINODIPHENYL SULFONE (DAPS)

To investigate the dynamic solvent effects on the formation of the ''t wisted intramolecular charge-transfer (TICT)'' state, the pressure as well as temperature effects on the fluorescence spectra of 4,4'-diamin odiphenyl suIfone (DAPS) in alcohol solvents were examined. It is conc luded that sol;rent viscous friction makes an important contribution t o the rate of TICT-state formation of DAPS in alcohols. The contributi on of the dynamic solvent effect on the kinetics is well-separated fro m that of the intrinsic static contribution defined by transition-stat e theory (TST). The contribution of the solvation effect to the activa tion volume and activation energy of the TICT-state formation is also discussed.