A new mixed-ligand complex of copper(II) containing N-(2-pyridylmethyl)-2-pyrazinecarboxamide (NPyPzCa): Synthesis, molecular and crystal structure and properties of [Cu(NPyPzCa)(NO3)(DMSO)]

The copper(II) complex [Cu(NPyPzCa)(NO3)(DMSO)] (1) (N-(2-pyridylmethyl)-2-pyrazinecarboxamide [NPyPzCa]) has been synthesized and characterized by single crystal X-ray diffraction and ab-initio calculation, electrochemistry and TGA analysis. The Cu(II) atom exhibits a square base pyramidal geometry due to the coordination of three donor atoms from the carboxamide ligand and one oxygen atom from the NO3− ion in the equatorial plane and one DMSO in the axial position. There are some CH…O, CH…N and CH…π (aromatic) interactions that seem to be effective in the stabilization of the crystal packing. The electrochemistry of this complex shows a quasi-reversible one electron Cu(III/II) reduction near +0.35 V.