Chromium(III) Complexes with Some Optically Active α-Hydroxy Acids

Abstract

Complexes obtained from CrCl3Py3 with some optically active α-hydroxy acids have been characterized by elemental analysis, magnetic susceptibility, vibrational (IR), electronic and circular dichroism (CD) spectra. The magnetic susceptibility data are close to the spin-only value for a d3 chromium(III) ion in octahedral or distorted octahedral symmetry. Three (Cr—Cl) vibrational modes in the region 410-290 cm-1 are observed for some of the complexes indicating C2ν, local symmetry of ligand atoms around the chromium(III). In the electronic spectra two peaks are observed in the range 16949-18018 and 22986-24570 cm-1. They are assigned to d—d transitions in pseudo octahedral symmetry. The structure of the complexes is likely to be facial since strong and well defined Cotton effects are observed. The parameters (Dq, B, β35) for the complexes provide reassurance that pyridine nitrogen is preserved.