Photodissociation of Jet-Cooled Intramolecular Exciplex in 1-(9-Anthryl)-3-(p-(N,N-dimethylamino)phenyl)propane: Formation of Excited-State Anthryl and Deuteration Effect

The jet-cooled intramolecular exciplex formation and photodissociation were examined in deuterated anthryl bichromophoric EDA systems 1-(9-anthryl- d 8 )-3-( p -( N, N -dimethylamino)phenyl)propane (9-An- d -DMA) in comparison with the undeuterated compound (9-An-DMA) reported previously. The excess vibrational energy threshold for the exciplex formation in the former was considerably smaller than that of the latter. The photodissociation of the jet-cooled exciplex leading to the anthryl moiety fluorescence was observed in the excitation of the transient absorption band of the exciplex (S n ← S 1 ). It is noteworthy that very short decay times of anthryl fluorescence were observed upon photodissociation of the exciplex. The deuterated effect of the anthryl moiety on the formation and photodissociation of the exciplex may be attributable to the role of the vibrational level density of the anthryl in these excited-state reaction dynamics.