THE INFLUENCE OF INHERENT PSEUDO JAHN-TELLER INSTABILITY ON THE STRETCHING VIBRATIONS OF WATER-MOLECULES IN THE ISOMORPHOUS METAL(II) SACCHARINATE HEXAHYDRATES

The spectroscopic and crystallographic data for a series of isomorphou s hexahydrates of metal(II) saccharinates [where metal(II) is Zn(II), Cd(II), Mn(II), Fe(II), Co(II) and Ni(II)] were studied. The spectrosc opically determined frequencies of the stretching O-D vibrations of th e isotopically isolated HDO molecules were correlated with the crystal lographically obtained O-w...O distances. A regression analysis of dis tances vs. frequencies and vice versa was carried out and the experime ntally determined O...O distances were compared with the values obtain ed using the correlation equations. The experimental and the predicted frequencies for the stretching O-D vibrations were also compared. The agreement was satisfactory in both cases. Recorded were the RT and LN T Fourier-transform IR spectra of the saccharinate complex of divalent copper (also a member of the isomorphous series but characterized by inherent pseudo Jahn-Teller instability) and of its deuterated analogu es. An attempt was made to point at the possible spectroscopic consequ ences of the pseudo Jahn-Teller instability, especially in the spectra l region of the O-H and O-D stretching vibrations. (C) 1997 Elsevier S cience B.V.