Picosecond time-resolved resonance Raman spectra after excited state intramolecular proton transfer in 2-(2'-hydroxyphenyl) ben zoxazole have been investigated. The two most intense resonance Raman lines belonging to the SI-keto tautomer are assigned to vibrations with strong v(CO) and delta(NH) components, respectively. The intensities of corresponding anti-Stokes resonance Raman spectra indicate that the high-frequency modes are not directly vibrationally excited by the reaction. For modes below 1000 cm(-1) substantial excess populations were observed. The SI-keto tautomer is already close to thermal equilibrium after 2 ps and it cools down within about 8 ps. (c) 2005 Elsevier B.V. All rights reserved.