Matrix isolation spectroscopy of H2O, D2O, and HDO in solid parahydrogen

We present infrared (IR) absorption spectra over the 800-7800 cm(-1) region of cryogenic parahydrogen (pH(2)) solids doped with H2O, D2O and HDO molecules. Analysis of the rovibrational spectra of the isolated H2O, D2O and HDO monomers reveals their existence as very slightly hindered rotors, typically showing only 2-5% reductions in rotational constants relative to the gas phase. The nuclear spin conversion (NSC) of metastable J = 1 ortho-H2O (oH(2)O) and para-D2O (pD(2)O) molecules follow first order kinetics, with single exponential decay lifetimes at T = 2.4 K of 1900 +/- 100 s, and 860 +/- 50 s, respectively. We report without discussion some absorptions of water clusters produced during sample annealing. We report and assign a number of absorptions to oH(2)-water pairs or 'complexes'. The main features of the oH(2)-H2O and oH(2)-D2O spectra are explained qualitatively by assuming a semi-rigid C-2v structure with the oH(2) acting as a proton donor to the O atom. Surprisingly, NSC of oH(2)-water complexes proceeds at very nearly the same rate as for the corresponding water monomer. We report unassigned spectra of larger (oH(2))(n)-water clusters, and the even more surprising observation of the prolonged survival of oH(2)O and pD(2)O molecules clustered with several oH(2) molecules. We report and assign a number of water dopant-induced IR absorption features of the pH, host, along with cooperative water-pH(2) transitions in which the vibrational excitation of the pH(2), solid is accompanied by a pure rotational transition of the water dopant. (C) 2003 Elsevier B.V. All rights reserved.