Infrared spectra of isotopomers of chloromethylene in solid argon

We measured the IR spectra of the solid Ar-trapped chloromethylene (HCCl) prepared by electron bombardment of a CH₃Cl/Ar mixture during matrix deposition. Irradiation of matrix samples at 210 nm decreased the intensity of lines corresponding to HCCl, whereas irradiation at 385 nm had an opposite effect. The above behavior allowed an unambiguous identification of all vibrational modes of HCCl, and the obtained assignments were further confirmed by quantum chemical calculations and ¹³C/²H isotopic labeling experiments.