INFRARED SPECTRA OF WEAKLY-BOUND COMPLEXES AND COLLISION-INDUCED EFFECTS INVOLVING ATMOSPHERIC MOLECULES

摘要

Some of the links and gaps between collision-induced spectra and weakly-bound van der Waals complexes are outlined. Even though the spectrum of a complex is in a sense the direct low temperature limit of the corresponding collision-induced spectrum, there is a gap because the spectrum of a dimer at 'real world' (atmospheric) temperatures often cannot easily be determined from its known low temperature (molecular beam) spectrum. The infrared spectra of a 'family' of complexes of atmospheric interest are described: the nitrogen dimer, the carbon monoxide dimer, and the nitrogen-carbon monoxide complex. Although these complexes are isoelectronic with similar intermolecular forces, their spectra are very different due to symmetry effects. The challenge of measuring the spectrum of the water vapor dimer at atmospheric temperatures is described.