Collision induced absorption in compressed gaseous cyanogen and comparison with the liquid phase absorption in the region 20–120 cm–1

Abstract

The far infra-red bimolecular collision induced absorption of compressed gaseous cyanogen has been studied in the region 20–120 cm^–1, at pressures of up to 33.5 bar, together with the liquid spectrum at 301 K in the same region. From the integrated intensity of the gaseous absorption an apparent quadrupole moment of ±(14.7 ± 2.0)× 10^–26 e.s.u. was computed. A MO calculated value of –9.0 × 10^–26 e.s.u. has been quoted (McLean). For the liquid an apparent molecular quadrupole moment of ±(6.9 ± 1.0)× 10^–26 e.s.u. was deduced, the much lower value reflecting inter alia the reduced efficacy of multi-molecular collisions in generating induced dipoles.