Strongly hydrogen-bonded molecular complexes studied by matrix-isolation vibrational spectroscopy. Part 2.—Amine–hydrogen chloride complexes

Abstract

Infrared spectra are reported of strongly hydrogen-bonded complexes between amines (methylamine, ethylamine, dimethylamine and trimethylamine) and hydrogen chloride trapped in argon and nitrogen matrices. There are substantial differences between the spectra of the complexes in the two matrices, which are attributed to increased proton transfer from hydrogen chloride to the amine in the more polar nitrogen matrix. The extent of proton transfer increases from methylamine–hydrogen chloride in an argon matrix (where the proton is shared more or less equally between the nitrogen and chlorine atoms) to trimethylamine–hydrogen chloride in a nitrogen matrix (where the proton is substantially transferred to the amine).