Structures of hydrogen-bonded clusters of benzyl alcohol with water investigated by infrared-ultraviolet double resonance spectroscopy in supersonic jet

The structures of the benzyl alcohol and its hydrogen-bonded clusters with water have been investigated by infrared-ultraviolet double resonance vibra tional spectroscopy along with ab initio molecular-orbital calculations. Ch aracteristic shifts of the OH stretching vibrations of the benzyl alcohol s ite as well as the water sites were found, which are quite useful to determ ine the cluster structures. For bare benzyl alcohol, a planar conformer hav ing no intramolecular hydrogen bond is dominant in the jet. On the other ha nd, the dominant species becomes a gauche-type conformer in the benzyl alco hol-(H2O)(n) (n = 1-4) hydrogen-bonded clusters. In these clusters, the pi- hydrogen bond between the phenyl plane and the OH group of the water cluste r site is possible. Detailed intermolecular hydrogen bonding structures are discussed by comparing the observed spectra with the simulated spectra obt ained by ab initio calculations. (C) 1999 American Institute of Physics. [S 0021-9606(99)01142-3].