Pyridine N-oxide complexes of Cu(II) ions with pseudohalides: Synthesis, structural and spectroscopic characterization

•The Cu(II) complexes were characterized by microanalyses and physico-chemical methods.•The structures of complexes were determined by X-ray studies.•The studied complexes show distorted octahedral and square-planar geometries.•The thiocyanate ions have different positions in the studied compounds.

The presented work describes the synthesis of copper(II) thiocyanate and dicyanamide complexes with pyridine-N-oxide ligands in water/methanol solution at ambient temperature. The synthesized compounds, [Cu(SCN)2(pyrO)2] (1), [Cu(SCN)2(bypO2)] (2), [Cu(dca)(PF6)(bypO2)2(H2O)]n (3) and [Cu(bypO2)3](BF4)2·4H2O (4) where pyrO, bypO2 and dca are pyridine-N-oxide, 2,2′-bipyridine-N,N′-dioxide and sodium dicyanamide, were characterized by microanalyses and physico-chemical methods. Single crystal X-ray diffraction analyses revealed that complexes 1, 2 and 4 are mononuclear, while complex 3 is polynuclear, in which copper(II) ions are linked by μ1,5-dca bridges.

Graphical abstractA series of copper(II) complexes with pyridine N-oxide (pyridine-N-oxide, 2,2′-bipyridine-N,N′-dioxide) and pseudohalide (dca, SCN) ligands have been synthesized and characterized by elemental analysis, TG, EPR, IR spectra and X-ray diffraction. The cis and trans disposition of the SCN anions, as well as the square-planar and octahedral environments of the copper ions in these complexes were identified.Figure optionsDownload full-size imageDownload as PowerPoint slide