COLLISION-INDUCED FIRST OVERTONE BAND OF H-2 IN H-2-KR AND H-2-XE MIXTURES

摘要

Enhancement of the collision-induced absorption (CIA) spectra of the first overtone infrared band of H-2 in the H-2-Kr and H-2-Xe binary mixtures were recorded at 295 K for base densities of H-2 in the range 30-57 amagat and for partial densities in the range 50-250 amagat far each of Kr and Xe. The observed spectra consist of single transitions O-2(J), Q(2)(J), and S-2(J) corresponding to the selection rule Delta J = -2, 0, and 2, respectively. Binary, ternary, and quarternary absorption coefficients of the band arising from collisions of the type H-2-X, H-2-X-X, H-2-H-2-X, H-2-X-X-X, H-2-H-2-X-X, and H-2-H-2-H-2-X, where X represents Kr or Xe, have been determined from the integrated absorption coefficients of the band. The spectra are interpreted in terms of the quadrupolar induction mechanism and net evidence of the contribution from the isotropic overlap induction mechanism is found unlike in the CIA spectra of the fundamental band of H-2 [see S. P. Reddy, in Phenomena Induced by Intermolecular Interactions, edited by G. Birnbaum (Plenum, New York, 1985), p. 129]. Analysis of the absorption profiles of the observed spectra was carried out using the Birnbaum-Cohen line-shape function [G. Birnbaum and E. R. Cohen, Can. J. Phys. 54, 593 (1976)] for individual components of the band and characteristic line shape parameters were determined from the analysis. (C) 1997 American Institute of Physics. [References: 24]