Polarized electronic spectra of quadrate chromium(III) complexes

Abstract

Polarized electronic spectra of single crystals of mixed trans-diacidobis(ethylenediamine)chromium(III) complexes, where the diacido groups are aquohydroxy, aquofluoro, aquochloro, aquobromo, and bromochloro, have been measured at liquid nitrogen temperature. On the basis of polarization characteristics, the observed quartet bands have been given definite quadrate assignments. The band maxima have been fitted with the theoretical energy equations of d 3 configuration immersed in tetragonal ligand field including full configuration interaction but neglecting spin-orbit perturbation. The Dq, Dt, ϰ parameters of the ligand field and the B parameter of the electron correlation have been evaluated by such a fitting and compared with those obtained earlier by us and others for the other trans-diacido systems. A rich doublet structure was uncovered in the 14,000–16,000 cm −1 region for the aquofluoro complex and in the 21,000 cm −1 region for the aquobromo complex. The doublet bands in the 21,000 cm −1 region have been uncovered for the other systems also.