Intra- and intermolecular components of the ν2 forbidden band of CF4 in pure gas and in He, Ar, Xe and N2 mixtures

Abstract

Spectra of CF4 as pure gas and in mixtures with gaseous He, Ar, Xe and N2 were obtained in the region of the forbidden ν2 band at pressures from about 1 atm up to 100 atm at ambient temperature. The absorption consists of two components depending on the gas pressure. The first, with an integrated intensity (cm−2 Amagat−1) that is independent of pressure, arises through the Coriolis or intramolecular interactions. The second, varying linearly with the partial pressure, is attributable to additional absorption arising during intermolecular binary collisions. The intensity of each of these components was measured and analysed, and from the results we are able to draw some conclusions concerning the collision-induced mechanisms responsible for the absorption.