Abstract of "Variations in the Strength of the Infrared Forbidden 2328.2 cm^-1 Fundamental of Solid N₂ in Binary Mixtures." M. P. Bernstein and and S. A. Sandford. Spectrochimica Acta, Part A, Molecular Spectroscopy. 55 (1999) 2455-2466.

We present the 2335-2325 cm^-1 infrared spectra of solid nitrogen and binary mixtures of N₂ with other molecules at cryogenic temperatures. Band positions, profiles, and intrinsic strengths (A values) of the NšN stretch are presented for various N₂ -CO₂ and N₂-H₂O mixtures at 12 K. The data demonstrates that the strength of the infrared forbidden N₂ fundamental near 2328 cm^-1 is strongly enhanced in the presence of CO₂ and H₂ O, but not affected by O₂, CH₂, or CO. The mechanisms proposed for the enhancements in N₂-H₂O and N₂-CO₂ mixtures are fundamentally different. In the first case hydrogen bonding may be the cause, in the second there appears to be a resonant exchange between the CO₂ and N₂ resulting in enhancements of hundreds in the intensity of the N₂ fundamental. Possible implications for astrophysics are also briefly discussed.