Analysis of the vibrational spectra of the hexakis(pyridine N-oxide)metal(II)perchlorates

Abstract

The far infrared (far i.r.) and laser Raman spectra of M(C 5H 5NO) 6(ClO 4) 2 (M = Co 2+, Ni 2+, CU 2+ and Zn 2+) are reported in the 500-100 cm −1 region. The compounds are all isomorphous and crystallize in the space group R 3 . The metal coordination sphere has S 6 symmetry. A normal coordinate analysis of the vibrational spectra in the metal—ligand region yields excellent agreement between observed and calculated bands, however, anomalous vibrational absorption in the copper(II) analog requires reduction of the copper site symmetry from S 6 to C i . This indicates the presence of a static Jahn—Teller distortion on the vibrational time scale.