Anion modulated structural variations in copper(II) complexes with a semicarbazone Schiff base: Synthesis, characterization and self assembly

Two copper(II) complexes, [Cu(L)N3]n (1) and [Cu(HL)2](I3)ClO4 (2), where HL = 2-pyridylaldehydesemicarbazone, have been prepared and characterized by elemental analysis, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. Complex 1 crystallizes in monoclinic space group P21/a, whereas, complex 2 crystallizes in triclinic space group P-1. Complex 1 is a stair-like coordination polymer with square pyramidal geometry of copper(II), whereas, complex 2 is a mononuclear cationic bis-ligand complex of octahedral copper(II). Lower coordination ability of tri-iodide or perchlorate compared to azide may be related with variations of the structures of the complexes.

Graphical abstractTwo copper(II) complexes have been prepared using a flexidentate semicarbazone Schiff base. The formation of the complexes with different stereochemistry could be controlled by the tactful choice of counter anions.Figure optionsDownload full-size imageDownload as PowerPoint slide