Synthesis, structural elucidation, thermal and antimicrobial studies of a heteroleptic Cu(II) complex incorporating hydrogen phthalate and N,N,N′,N′-tetramethylethylenediamine

Abstract

A copper(II) complex of N,N,N′,N′-tetramethylethylenediamine and o-phthalic acid, [Cu(tmen)(Hpht)2] (1) (where Hpht1− is the monoanion of o-phthalic acid and tmen is N,N,N′,N′-tetramethylethylenediamine), has been synthesized and structurally characterized by elemental combustion analysis, UV–Visible spectroscopy, FTIR spectroscopy, and single crystal X-ray crystallography. The CuN2O4 chromophore is defined by two nitrogens of N,N,N′,N′-tetramethylethylenediamine and four carboxylate oxygens of two Hpht1– groups, resulting in a highly distorted cis-octahedral coordination geometry, due to large Jahn–Teller distortion. The two Hpht1– groups coordinated to Cu(II) are in a cis disposition, and their four carboxylato-oxygen atoms from two different Hpht1– groups coordinate in an asymmetric chelating fashion. The crystal structure of this copper(II)-Hphthalate-tmen monomer is consolidated by O–H····O and C–H····O hydrogen bonds and C–H····π interactions. The antibacterial properties of 1 and two other complexes, [Cu(bipy)(cinn)(H2O)] (2) and [Cu(en)(sal)Cl] n (3), against strains Bacillus spizizenii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus Aureus, and Aspergillus niger were also investigated.