f-f spectral studies of holmium(III) complexes

Abstract

Holmium(III) mixed-ligand complexes containing ligands having oxygen and nitrogen donors have been spectrophotometrically investigated. The observed spectra in the visible region have been analysed to calculate covalency parameters (β, b^½ and δ), oscillator strengths and Judd-Ofelt parameters. The degree of covalency in the complexes increases with increase in coordination number. The hypersensitivity is correlated with the degree of covalency and number of coordinated ligands. The higher values of covalency parameters, oscillator strength and magnetic moment in the ten-coordinate Ho^III is taken as evidence of participation of f-orbitals in bonding.