Spectroscopic and ab initio studies of ionic hydrogen bonds: the O–H stretch vibration of SiOH+–X dimers (X=He, Ne, Ar, N2)

Infrared photodissociation spectra of SiOH+–X dimers with X=He, Ne, Ar, and N2 are analyzed in the vicinity of the O–H stretch (ν1) vibration of SiOH+. The observed complexation-induced red-shifts, Δν1=−8.4(3.0), −35.7(6), −217.42(1), and −517.1(5) cm−1, are consistent with the linear proton-bound global minimum structures predicted by ab initio calculations at the MP2 level of theory. Empirical relations between the magnitude of Δν1 and the interaction strength of the ionic hydrogen bond are discussed.