Synthesis, crystal structure, DFT and spectroscopic studies of mononuclear chromium(III) complex with bidentate ligand

The mononuclear neutral Cr(III) complex, [Cr(L)3] (1) (where LH = 4-methyl-2,6-dibenzoylphenol (mdbpH)) has been synthesized and characterized by elemental analysis, conductivity measurement, mass spectrometry, IR, electronic and ESR spectroscopy, cyclic voltammetry and X-ray crystallography. Crystal structure determination reveals that 1 comprises three monoanionic bidentate ligands (2,6-PhCO)2(4-Me)C6H2O− coordinating through phenolic O and benzoyl O atoms to give a mer-CrO3O3 octahedral configuration. The optimized geometry and the electronic transitions of the complex were calculated using methods based on the density functional theory. The ESR spectra indicate a weak tetragonal distortion. The redox behavior was studied by cyclic voltammetry and was compared with that observed for the free ligand.

Graphical abstractThe synthesis, crystal structure and electrochemical behavior of chromium(III) complex with a bidentate ligand are described. The ESR study suggests a weak tetragonal distortion. X-ray data and electronic spectra have been compared with DFT calculations.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A one-pot synthesis of [Cr{(2,6-PhCO)2(4-Me)C6H2(O)3}] is reported. ► X-ray structure analysis confirmed meridional octahedral configuration. ► The ESR study suggests a weak tetragonal distortion. ► DFT-B3LYP/3-21 G method showed good correlation with the experimental X-ray and electronic spectral data. ► Cyclic voltammetric studies indicate two metal centered reductions on the electrode surface.