Copper(II) Complexes With Bis-Schiff Bases: Synthesis, Crystal Structures, and Antibacterial Activities

Abstract

Reaction of copper perchlorate with the tridentate Schiff bases N,N’-bis(5-methoxysalicylidene)-1,2-ethanediamine (H2L1) and N,N’-bis(5-chlorosalicylidene)-1,3-propanediamine (H2L2), afforded a dinuclear complex, [Cu2(L1)2]·2CH3OH (1), and a mononuclear complex, [CuL2] (2). The complexes were characterized by single-crystal X-ray diffraction, FT-IR, and elemental analysis. The Cu atom in complex 1 is in a square pyramidal coordination, with two phenolate O and two imine N atoms of L1 ligand defining the basal plane, and with one phenolate O atom of another L1 ligand occupying the apical position. The Cu atom in complex 2 is coordinated by two phenolate O and two imine N atoms of L2 ligand, forming a tetrahedrally distorted square planar geometry. The free Schiff bases and the complexes were assayed for antibacterial activities. Both complexes are more active against the bacteria than the free Schiff bases. Complex 2 has the MIC value of 0.10 μg mL−1 against Bacillus subtilis.