Synthesis, crystal structure and magnetic properties of a new binuclear copper(II)-copper(II) complex of a macrocyclic oxamide

Abstract

The binuclear metal complex [Cu(μ-exoO₂)cyclamCu(bpy)](ClO₄)₂·H₂O (bpy = 2,2′-bipyridine and (exoO₂)cyclam = 1,4,8,11-tetraazacyclotradecanne-2,3-dione) has been synthesized and characterized by single-crystal X-ray analysis and spectroscopic and magnetic measurements. The structure consists of homobinuclear [Cu(μ-exoO₂)cyclamCu(bpy)]²⁺ cations, a weakly coordinated water molecule and perchlorate ions. In each binuclear unit, Cu1, coordinated by four nitrogen atoms of the macrocyclic organic ligand is connected to Cu2 via the exo-cis oxygen atoms of the macrocyclic ligand with Cu···Cu separations of 5.151 Å; Cu2 assumes square-pyramidal geometry. Magnetic properties measured at 2–300 K show antiferromagnetic exchange between adjacent copper(II) ions.

Keywords:

• Copper(II)
• Crystal structure
• Oxamido bridge
• Macrocyclic ligand
• Magnetic properties

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Nos 20471031, 90101028, 203310100) and the Natural Science Key Foundation of Tianjin.