STRUCTURAL INVESTIGATIONS OF TRANSITION-METAL (II) TETRACYANONICKELATE COMPLEXES OF 3-CHLOROPYRIDINE USING FOURIER TRANSFORM-INFRARED AND LASER RAMAN-SPECTROSCOPY

The FT-IR and laser-Raman spectra of five new complexes of the formula ML2Ni(CN), (where M = Mn, Fe, Ni, Zn or Cd; L = 3-chloropyridine) are reported. The complexes are shown to have a structure consisting of two-dimensional polymeric layers formed with Ni(CN)4 ions bridged by ML2 cations. For a given series of isomorphous complexes, the effects of metal ligand bond formation on the ligand vibrational modes are examined and the metal-sensitivity sequence of the ligand frequencies is found to be Mn almost-equal-to Cd < Fe < Zn < Ni.