The structure of 4-methylphenol and its water cluster revealed by rotationally resolved UV spectroscopy using a genetic algorithm approach

Abstract

The structure of 4-methylphenol (p-cresol) and its binary water cluster have been elucidated by rotationally resolved laser-induced fluorescence spectroscopy. The electronic origins of the monomer and the cluster are split into four sub-bands by the internal rotation of the methyl group and of the hydroxy group in case of the monomer, and the water moiety in case of the cluster. From the rotational constants of the monomer the structure in the S-1 state could be determined to be distorted quinoidally. The structure of the p-cresol-water cluster is determined to be trans linear, with a O-O hydrogen bond length of 290 pm in the electronic ground state and of 285 pm in the electronically excited state. The S-1-state lifetime of p-cresol, p-cresol-d(1), and the binary water cluster have been determined to be 1.6, 9.7, and 3.8 ns, respectively. (C) 2005 American Institute of Physics.