Synthesis, characterization, crystal structures, and antimicrobial activity of cobalt(II) and iron(III) complexes derived from N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide

Abstract

A new cobalt(II,III) complex, [CoIIIL2]2[Co2II(HL)2(OH2)2(CH3OH)2] • 2H2O (I) and a new iron(III) complex, [FeIII(HL)2](NO3) (II), where L2– and HL– are the dianionic and monoanionic form of N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide, respectively, have been prepared and characterized by elemental analyses, infrared and UV-Vis spectroscopy and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1417971 (I), 1417979 (II)). Complex I crystallizes in the monoclinic space group P21/n with unit cell dimensions a = 16.1665(9), b = 14.5692(8), c = 19.086(1) A, β = 96.347(1)°, V = 4467.9(4) A3, Z = 2, R1 = 0.0521, and wR2 = 0.1411. Complex II crystallizes in the orthorhombic space group Pbcn with unit cell dimensions a = 12.475(1), b = 12.202(1), c = 18.859(2) A, V = 2870.8(4) A3, Z = 4, R1 = 0.0796, and wR2 = 0.1981. The metal atoms in the complexes are in octahedral coordination. Crystals of the complexes are stabilized by hydrogen bonds. The efficiency of the aroylhydrazone and the two complexes was evaluated against B. subtilis, S. aureus, E. coli, P. fluorescence, C. albicans and A. niger, with the complexes demonstrating enhanced activity relatively to the free ligand.