Synthesis, crystal structure and antimicrobial activity of a new polymeric copper(II) complex derived from N'-(pyridin-2-ylmethylene)isonicotinohydrazide

A new polymeric copper(II) complex [Cu3L3(mu(3)-NO3)](n)center dot 2nNO(3), derived from the Schiff base ligand N'-(pyridin-2-ylmethylene)isonicotinohydrazide (HL) with copper nitrate in methanol, was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The structure of the complex was further confirmed by single crystal X-ray diffraction technique. The Schiff base ligand coordinates to the Cu atoms through the phenolate O, imino O, and two pyridine N atoms. The Cu atom is in a square pyramidal coordination, with the three chelate donor atoms of the Schiff base ligand and the terminal nitrogen donor atom of a symmetry related Schiff base ligand defining the basal plane, and with one oxygen atom of the coordinated nitrate ligand at the apical position. The nitrate ligand bridges three [CuL] units with a crystallographic three fold rotation axis symmetry. The effect of the complex on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.