INFRARED-SPECTRA OF THE H-2-N-2 AND H-2-CO VANDERWAALS COMPLEXES

Spectra of the weakly bound van der Waals complexes H2-N 2 and H2-CO have been studied in the mid- and far-infrared regions corresponding to H2 vibrational and pure rotational frequencies, respectively. The experiments were done using a Fourier transform infrared spectrometer to study equilibrium gas samples at low temperature (77 K) with a long absorption path. The spectra of the complexes appear as fine structure located near the peaks of the lines in the collision-induced spectrum of hydrogen. Compared to earlier studies of these species, the present results have more complete coverage of the various possible transitions, better resolution, and better signal to noise. New structure is reported which corresponds to hindered rotational transitions of the N2 component of an H2-N2 complex and is reminiscent of patterns observed for the N2-Ar and (N2)2 complexes. The relation of these results to far-infrared measurements of Saturn's satellite Titan, made by the Voyager spacecraft, is discussed. © 1990 American Institute of Physics.