Infrared Study of Matrix-Isolated Chlorinated Tetrahedral Molecules

Abstract

The infrared spectra of CH3Cl, CH3CH2CH2Cl, CH2Cl2, HCCl3, (CH3)–CCl3, FCCl3, BrCCl3, CCl4, and SiCl4 in an argon matrix at 20°K were studied. The chlorine isotopic splitting pattern of the bands in the 500–1300-cm−1 region were recorded, and most of the isotopic frequencies were assigned. Normal-coordinate calculations have been performed on these molecules to establish complete chlorine isotopic splitting patterns of all the fundamental vibration bands. Different isotopic species have different Fermi resonance interactions in the same band system; examples of this were observed in the spectra of FCCl3 and CCl4.