FTIR studies of HCl dissolved in liquid CO: Anharmonic effects in the weak OC…HCl complex

FTIR spectra of HCl dissolved in liquefied CO have been studied in the wide range of frequencies ∼100-7000 cm−1. Both the librational mode, fundamental, first overtone and combination bands of the OC…HCl complex were registered at the lowest ∼95 K temperature of the liquid solution. CCD ab initio calculations utilizing the 6-311++G(3df,3pd) basis set have been performed to analyze geometry of the most stable structure and parameters of anharmonic potential energy and dipole moment functions, which define the basic spectroscopic features of the complex. The results obtained have been compared with those estimated on the base of model treatment of anharmonic interactions between HCl and CO constituents.