Iqbal Azhar, Pegg Lara-Jane, Stavros Vasilios G
Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
J Phys Chem A. 2008 Oct 2;112(39):9531-4. doi: 10.1021/jp802155b. Epub 2008 Jun 10.
The active role of the optically dark pi sigma* state, following UV absorption, has been implicated in the photochemistry of a number of biomolecules. This work focuses on the role of the pi sigma* state in the photochemistry of phenol upon excitation at 200 nm. By probing the neutral hydrogen following UV excitation, we show that hydrogen elimination along the dissociative pi sigma* potential energy surface occurs within 103 +/- 30 fs, indicating efficient coupling at the S1/S2 and S0/S2 conical intersections, with no identifiable role of statistical unimolecular decay of vibronically excited (S0) phenol in the timeframe of our measurements.
