Femtosecond fluorescence upconversion studies of excited-state proton-transfer dynamics in 2-(2 ‘-hydroxyphenyl)benzoxazole (HBO) in liquid solution and DNA

H. Wang, H. Zhang, O.K. Abou-Zied, C. Yu, F.E. Romesberg, M. Glasbeek, Chem. Phys. Lett. (2003) 367:599–608.
pubpic200wangWe find that the typical time for the excited-state intramolecular proton-transfer reaction of the syn-enol tautomer in solution and in DNA is 150 fs. Picosecond rise and decay components in the fluorescence transients with characteristic times between 3 and 25 ps are observed and attributed to the effects of vibrational cooling.