Site selective electronic spectroscopy and ligand field analysis of sodium cis-bis(iminodiacetato) chromate(III) Original Research Article

The five components of the 2Eg and 2T1g (Oh) states have been identified from the site selective low temperature excitation spectrum of Na[Cr(IDA)2] · 1.5H2O. A ligand field analysis in the framework of the angular overlap model was performed to fit the unusually large (∼ 2000 cm−1) overall doublet splitting of this complex. Accounting for the effects of anisotropic π-bonding and the anisotropy in the interelectronic repulsion term as judged essential. The ligand field strength of the nitrogens is smaller than it is in amine complexes, because of inductive electron donation from the amino to the acetate group. The previously reported fluorescence emission did not occur in this complex, and only phosphorescence was observed in the solution luminescence spectrum. The photophysical properties, focused on the emission behavior, are discussed.