HCl Dissociation in Methanol Clusters from Ab Initio Molecular Dynamics Simulations and Inner-Shell Photoelectron Spectroscopy

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2014-08, Vol.118 (34), p.6900-6907
• Main Authors: Abu-samha, Mahmoud, Børve, Knut J
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp504883r

HCl dissociation in methanol clusters is studied by ab initio molecular dynamics simulations and experimentally by X-ray photoelectron spectroscopy. From theoretical simulations of HCl in oligomers and medium-sized clusters of methanol, two states of solvation are identified for HCl: an intermediate proton-sharing (ion pair) state and a fully dissociated state. Lowering the temperature from 150 to 100 K is found to promote full dissociation over the proton-sharing state. The dissociation of HCl is well reflected in the experimental chlorine 2p photoelectron spectrum recorded for a beam of clusters formed by adiabatic expansion of the vapor over a solution of HCl in methanol. In order to reproduce the observed Cl 2p spectrum by means of theoretical line-shape modeling, one needs to take into account both the intermediate proton-sharing state and the fully dissociated state.