Synthesis, crystal structure and spectral properties of a copper(II) complex with flavonoxylacetate ligand.

A new Cu(II) complex with flavonoxylacetate ligand was synthesized and characterized. The structure of the complex was determined by X-ray single crystal diffraction technique. In the crystal structure, flavonoxylacetate coordinates Cu(II) ion in bidentate mode resulting in a chelating pentagonal coordination structure. Central Cu(II) has an elongated octahedral coordination showing a strong Jahn-Teller effect. The stability of the crystal structure was investigated by thermal gravimetric analyses. The loss of coordination water in crystals occurs above 150 °C. Fluorescence spectra are affected by pH value and coordination metal ion as well as the substitution pattern of the carboxymethoxy on the flavone skeleton. Furthermore, the fluorescence quenched in the Cu(II) complex recovered with increase of S^2- ion concentration. [ABSTRACT FROM AUTHOR]