Knowledge Bank

A systematic theoretical study of the structures and vibrational spectra of hydrogen-bonded complexes of hydrogen hailides (HF, HCI and HBr) with nitrogen bases at the MP2/6-31+G(d,p) level has been underway for $sometimea,b$. The basicity of these bases has been varied by changing the attached substituents to give complexes whose structures span the range of proton positions from Y-H...N neutral molecule complexes through proton shared Y...H...N bonds to proton transferred $Y-\dots +H-N$ ion pairs. In this presentation we should like to begin reporting result from experimental studies of some of these complexes isolated in inert low temperature argon matrices. We shall show how the calculations help with the interpretation of these result, particularly with the complex pattern of very strong multiple absorption bands characteristically observed in the experimental spectra of many of these systems.