PHOTOPHYSICAL BEHAVIOR OF 4,4'-DIHYDROXYDIPHENYL SULFONE

The effect of solvents on absorption and fluorescence of 4,4'-dihydrox ydiphenyl sulphone (DHDPS) indicates that the net effect of two electr on donating hydroxyl groups is very less on spectra of diphenyl sulpho ne (DPS). The small solvatochromic shifts also reveal that the change in dipole moment of DHDPS during excitation is negligible. Its behavio ur in S-1 state is found to be different from diaminodiphenyl sulphone s which possess twisted intramolecular charge transfer (TICT) characte r. Acidity constants for neutral-monoanion equilibria in S-0 and S-1 s tates have been determined and discussed.