Infrared absorptions of the H2O⋯H2 complex trapped in solid neon

When a sample of neon to which have been added less than 1% each of H2 and H2O is deposited at 4.3 K, the infrared spectrum of the resulting solid includes an absorption by the vibrational fundamental of H2, which is normally infrared inactive. New absorptions are also associated with the vibrational fundamentals of the H2O in the sample. Similar results are obtained for deuterium-enriched samples. The new peaks are assigned to the van der Waals complex of H2O with H2. As has been found in earlier theoretical, gas-phase, and solid-state studies of this and closely related systems, the infrared absorptions arise principally from complexes involving ortho-H2, for which J=1.