Torsional relaxations from perpendicular to tilted configurations in the intramolecular charge transfer of excited 9,9′-bianthryl as studied by femtosecond-picosecond time-resolved absorption spectral measurements in solution

Femtosecond-picosecond time-resolved absorption spectral measurements on 9,9′-bianthryl in polar alkanenitrile solvents revealed that the rise curve of the charge-transfer (CT) state contained components with rise times considerably longer than the solvent τL, which indicated the importance of the torsional relaxation from the approximately perpendicular to the tilted configuration in the CT state formation.