IR spectra of hydrogen bonding of H2S doped in Kr solids

Infrared spectra of H2S doped in Kr solids were obtained by Fourier transform infrared spectroscopy in the region of hydrogen bonding and interpreted on the basis of ab initio density functional theory calculations. Experimentally observed absorption peaks were assigned to a monomer, dimer, and trimer based on the intensity-dilution ratio relationships. The dimer produces a strong absorption at 2575 cm(-1) and appears to involve at least two weak absorptions in the region of the monomer bands. The ab initio calculation revealed that the dimer has an almost linear form in the gas phase. One H atom is donated from one H2S molecule and is accepted by the S atom of the other H2S molecule by hydrogen bonding. A similar structure is expected in Kr solids. The absorption intensity corresponding to the stretching of the hydrogen bond is significantly enhanced and is responsible for the strong peak at 2575 cm-1. An isotope peak was also observed at 2.1 cm(-1) below this strong peak in accordance with the ab initio calculations. The experimentally observed peak at 2566 cm(-1) was assigned to the stretching of hydrogen bonds in the trimer. (C) 2002 Elsevier Science B.V. All rights reserved.