8894
J. Phys. Chem. A 1998, 102, 8894-8902
Femtosecond Double Proton-Transfer Dynamics in [2,2′-Bipyridyl]-3,3′-diol in Sol-Gel Glasses P. Prosposito,† D. Marks, H. Zhang, and M. Glasbeek* Laboratory for Physical Chemistry, UniVersity of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands ReceiVed: April 13, 1998; In Final Form: July 17, 1998
Intramolecular excited state double proton-transfer dynamics has been studied for [2,2′-bipyridyl]-3,3′-diol (BP(OH)2) in sol-gel glass. By means of the femtosecond fluorescence up-conversion technique, the spectral dependence of the fluorescence transients obtained for BP(OH)2 in a few sol-gel glasses has been followed. From the temporal behavior of the reconstructed spectra, two concurrent double proton-transfer pathways are concluded to occur in the sol-gel hosts: the first is a concerted double proton-transfer process (within 100 fs after the excitation pulse) and the second is a two-step process involving the reaction from the excited dienol-to-monoketo tautomer (
