Synthesis, crystal structure, electrochemical and bioactivities of pyridine-2-carboxylato bridged copper(II) complexes

Two carboxylato bridged copper(II) complexes have been synthesized and characterized: [Cu4(2-Pca)4(NH)2(bipy)2](ClO4)2·H2O (1) and [Cu(2-Pca)2]n·3H2O (2), (2-Pca = the pyridine-2-carboxylate ion, NH = nicotinic acid hydrazide and bipy = 2,2′-bipyridine). Two types of bridging are present in 1; NH makes a bridge between the two copper atoms, along with 2-Pca. The crystal structure is stabilized by hydrogen bonds of the O–H…O type. Complex 1 belongs to triclinic system, having space group P1¯. The copper–copper separation is 5.3220(5) Å for 1. The coordination geometry of 1 is distorted square pyramidal and significant π…π stacking interactions are also present. The electrochemical and epr spectral studies at 77 K of complexes 1 and 2 have been investigated. Cleavage activities of both complexes have been investigated on double stranded pBR322 plasmid DNA by gel electrophoresis. Superoxide dismutase and antibacterial activity of both complexes have also been measured and discussed.

Two carboxylato bridged copper(II) complexes have been synthesized and, in one case, structurally characterized by X-ray crystallography. The crystal structure is stabilized by hydrogen bonds of the O–H…O type. Complex 1 belongs to the triclinic system, having space group P1¯. The copper–copper separation is 5.3220(5) Å for 1. The coordination geometry of 1 is distorted square pyramidal. Significant π…π stacking interactions are present in complex 1.Figure optionsDownload as PowerPoint slide