Matrix-Isolation Study of the Hydrogen Cyanide Dimer

Abstract

On the basis of the infrared spectra of HCN and DCN in Ar, N2, and CO matrices at temperatures from 4.5° to 20.5°K, it is concluded that there is no evidence for rotation of the monomeric species in these matrices and that the dimer has a linear or nearly linear HCN·HCN structure. The Lippincott-type potential is used to calculate frequencies for the stretching of the hydrogen bond and for the torsion about the hydrogen bond. These calculated frequencies are compared with our observed far-infrared spectra of dimers in the matrix and with available Raman data on crystalline HCN and DCN.