DOUBLE PROTON SHIFTS IN ASSOCIATES OF FORMIC-ACID WITH CH4, NH3, H2O,CH3F, NH2F, HOF, AND HF MOLECULES

The mechanisms of double synchronous proton transfer in associates of formic acid with solvent molecules of the HC(O)OH ... X (X = CH4, NH3, H2O, or HF) and HC(O)OH ... FH ... Y (Y = CH3F, NH2F, HOF, F-2, or HF ) types have been studied by an ab initio (SCF/3G) method. The calcula ted activation barriers of the reactions are 78.52, 17.72, 9.91, and 7 .06 kcal mol(-1) in the former case and 120.1, 259.4, 228.7, 182.8, an d 0.35 kcal mol(-1) in the latter case. In the latter case, simultaneo usly with the double transfer of protons, migration of two fluorine at oms along the chain of the associate occurs.