Metal-ligand coordination and antiradical activity of a trichromium(III) complex with the flavonoid naringenin

<p>The trinuclear chromium(III) complex [Cr<sub>3</sub>O(CH<sub>3</sub>CO<sub>2</sub>)<sub>6</sub>(L)(H<sub>2</sub>O)<sub>2</sub>] (where L is the monoanion of the flavonoid naringenin) was synthesized and characterized. Density functional theory (DFT) calculations and quantum theory of atoms in molecules (QTAIM) analysis show that the flavonoid binds to Cr<sup>III</sup> as an <i>O,O</i>-bidentate ligand via the 5-hydroxy and 4-oxo groups. Reactions with 2,2-diphenyl-1-picrylhydrazyl (DPPH) indicate that the antiradical activity of this flavonoid-metal complex is enhanced in comparison with uncoordinated naringenin.</p>