X-RAY-ABSORPTION NEAR-EDGE STRUCTURE STUDIES OF SOME MIXED-LIGAND COBALT(II) COMPLEXES

X-ray K-absorption spectra of some structurally important cobalt(II) m ixed ligand complexes have been recorded using a Cauchois type bent cr ystal X-ray spectrograph of 0.4 m radius. The complexes investigated i n the solid state have EDTA as a primary ligand and chloride, bromide, acetate, nitrite, dinitrite, thiosulphate, glycinate, ethylenediamine and di(ethylenediamine) ions as the secondary ligands. The observed X -ray absorption parameters e.g. chemical shift, edge-width, shift of t he principal absorption maximum and white line have been utilised to i nterpret the structure of the complexes. The results have been discuss ed qualitatively in terms of molecular symmetry, nature of the ligand and ionicity of the complexes.