Direct versus indirect H atom elimination from photoexcited phenol molecules.
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.
Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
Azhar
A
Iqbal
Lara-Jane
LJ
Pegg
Vasilios G
VG
Stavros
D004735:Energy Transfer; D005453:Fluorescence; D006859:Hydrogen / Q000737:chemistry*; D019800:Phenol / Q000737:chemistry*; D010777:Photochemistry; D017785:Photons; D014466:Ultraviolet Rays; D014732:Vibration
D019800:Phenol; D006859:Hydrogen