Structural investigation of Cu(II) complexes with dibromo 7-hydroxycoumarin derivatives using methodology based on XAS

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2020-10, Vol.175, p.108047, Article 108047
• Main Authors: Klepka, M.T., Kalinowska, D., Barboza, C.A., Drzewiecka-Antonik, A., Ostrowska, K., Wolska, A.
• Format: Article
• Language: English
• Subjects: 7-hydroxycoumarin; Coordination compounds; Copper; Copper compounds; Coumarin; Coumarin derivatives; Cu(II) complex; Multi-technique; Oxygen atoms; Rings (mathematics); X ray absorption; XAFS
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2018.11.001

Two new copper(II) complexes based on 6/8-acetyl-3,8/6-dibromo-7-hydroxy-4-methylcoumarin have been synthesized and structurally characterized. The electrochemical synthesis has been applied to enforce the complexation reaction. Characterization of non-crystalline product have been performed using methodology based on X-ray absorption spectroscopy. Both compounds have square planar geometry with four oxygen atoms in the nearest distance to the copper(II) ion. The hydroxycoumarin ligands coordinate to the cooper(II) either in bidentate or monodentate manner depending on the acetyl group position in the coumarin ring. The complexes have been evaluated from microbiological and cytotoxic point of view, but no significant activity has been found. •Two new dibromo 7-hydroxycoumarins have been synthesized and their complexes with Cu(II) were obtained.•Geometry of two new Cu(II) complexes of 6/8-acetyl-3,6/8-dibromo-7-hydroxy-4-metylocoumarin in have been determined.•Molecular structure of the complexes have been studied for non-crystalline form using methodology based on XFAS.