Electronic Structure and Spectral Study of Some Five Coordinate Complexes of Copper (II)

1-phenylazo-2-nephthol has been synthesized and used for complexation with Cu(II) metal ion along with pyridine, α-picoline, β- picoline, γ-picoline and water as secondary ligands. On the basis of elemental analysis and molar conductivity complexes were formulated as CuL2X [Where L is the prime ligand i.e 1-phenyl-azo-2-nephthol and X is the secondary ligand i.e. pyridine, α-picoline, β-picoline, and H2O.] The magnetic moment of these complexes (1.80 - 1.83 BM) indicates that these complexes are magnetically dilute. The appearance of 3 bands in the electronic spectra of complexes rules out the trigonal bipyramidal (D3h) symmetry arround Cu(II) ion in these complexes rather the electronic spectra favours square pyramidal (C4V) symmetry of these five coordinate complexes. The highest value of 10Dq clearly indicates the greater coordinating ability of α-picoline than pyridine, β-picoline and γ-picoline.