Spectroscopic Properties and Ligand-Field Analysis of the Bis(Ethylenediamine Monoacetato-N,N',O)Chromium(III) Moiety

The sharp-line absorption spectrum of (H(2)en)[Cr(edma)(2)](2)Cl-4 center dot 2H(2)O (edma=ethylenediaminemonoacetate) has been measured between 13,000 and 16,000 cm(-1) at temperatures down to 5 K. The emission, IR and UV-visible absorption spectra are measured as well. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The nine electronic bands due to spin-allowed and spin-forbidden transitions are assigned. Using the observed electronic transitions, a ligand-fi eld analysis is performed in the framework of the angular overlap model. The zero-phonon line in the sharp-line absorption spectrum splits into two lines that differ by 168 cm(-1); the large (2) E (g) splitting can be reproduced by ligand fi eld theory. The oxygen atoms of the edma ligand are confi rmed to have strong sigma- and pi-donor properties toward chromium(III).