CIRCULAR DICHROISM OF CHROMIUM(III) SEXADENTATE EDTA-TYPE COMPLEXES, PART I (S, S)-Ethylenediamine-N, N'-disuccinatochromate(III) and Ethylenediamine-N, N '-Diacetato-N, N'-Di-3-Propionatochromate(III) Ions

Abstract

Abstract New sexadentate Cr(III) complexes with (S, S)-ethylenediamine-N, N'-disuccinic acid (S, S-H4EDDS) and ethylenediamine-N, N'-diacetic-N, N'-di-3-propionic acid (H4EDDDA) are reported. With both ligands only trans(Os) geometrical isomers have been prepared. Infrared, electronic absorption, and CD spectra were used for characterizing the complexes. Because of the stereospecificity of the S, S-EDDS ligand the absolute configuration of the trans(O5)-Cr(S, S-EDDS)− is known. The (-)589-isomer of the trans(O5)-Cr(EDDDA)− complex, having a positive CD peak at lowest energy in the first spin-allowed d-d absorption band region, is tentatively assigned the A configuration, by comparison of its CD spectrum to the CD spectrum of the corresponding trans(Os)-Co(EDDDA)− and trans(O5)-Cr(S, S-EDDS)− complexes of known absolute configurations.