Solvation structure and transport of acidic protons in ionic liquids: a first-principles simulation study.
Ab initio simulations of a single molecule of HCl in liquid dimethyl imidazolium chloride [dmim][Cl] show that the acidic proton exists as a symmetric, linear ClHCl(-) species. Details of the solvation structure around this molecule are given. The proton-transfer process was investigated by applying a force along the antisymmetric stretch coordinate until the molecule broke. Changes in the free energy and local solvation structure during this process were investigated. In the reaction mechanism identified, a free chloride approaches the proton from the side. As the original ClHCl(-) distorts and the incoming chloride forms a new bond to the proton, one of the original chlorine atoms is expelled and a new linear molecule is formed.
Del Pópolo
Mario G
MG
Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN, UK. m.del-popolo@qub.ac.uk
Kohanoff
Jorge
J
Lynden-Bell
Ruth M
RM