Near-Infrared Absorption Spectra of Ortho- and Para-H2O in Solid Xenon and Argon

Abstract

The near‐infrared absorption spectra of H₂O trapped in solid argon and xenon have been studied at 20°K. The spectra, taken at concentrations of H₂O to matrix of 1:600, exhibit structure which is analyzed in terms of the known rotational and vibrational constants of the H₂O molecule. The results show that in solid xenon and argon matrices, the monomer H₂O exists as two modifications, one of which is rotating in its ground vibrational state. The theoretical intensities for the spectral bands of H₂O gas at 20°K are calculated and shown to agree with the bands observed in H₂O‐xenon. The changes in the observed intensities for other matrices are discussed. The changes in the spectra of the films when they are warmed to 35°K are shown and discussed.