Anharmonicity of water stretching vibrations in series of isomorphous crystalline hydrates. II. Metal(II) saccharinates hexahydrates (metal(II) is anelement of {Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd})

Using three theoretical models, the anharmonicity constants and the harmoni c eigenvalues of the O-H and O-D stretching vibrations were calculated for several members of the isomorphous series of metal(II) saccharinates hexahy drates (those of Cr, Mn, Fe, Co, Ni, Cu, Zn and Cd), on the basis of the ex perimentally obtained (by FTIR spectroscopy) frequencies of isotopically ;i solated OH and OD species. With a very few exceptions, the anharmonicity of the nu(OH(OD)) vibrations increases with the increase in the hydrogen bond strength. A good correlation was found to exist between the anharmonicity constants and the nu(OH(OD)) frequencies. The positions of the nu(OH(OD)) o vertones were estimated using the calculated anharmonicity parameters and t he predicted values for the OD oscillators were compared with the experimen tally obtained data. (C) 1999 Elsevier Science B.V. All rights reserved.