Infrared predissociation spectroscopy of cluster cations of protic molecules, (NH3)(n)(+), n=2-4 and (CH3OH)(n)(+), n=2,3

摘要

Infrared predissociation spectroscopy is carried out for the structure investigation of unprotonated cluster cations of protic molecules such as ammonia and methanol, which are generated through vacuum-ultraviolet one-photon ionization of their jet-cooled neutral clusters. The observed spectral features show that the cluster cations have the proton-transferred type structures, where a pair of a protonated cation and a neutral radical, NH4+center dot center dot center dot NH2 or CH3OH2+center dot center dot center dot OCH3, is formed. Theoretical calculations at the MP2 and B3LYP levels support the formation of the proton-transferred type structures for the cluster cations, and indicate that they are formed by proton-transfer following the photoionization of the neutral clusters. (C) 2008 American Institute of Physics.