Dioxomolybdenum(VI) complexes derived from tridentate hydrazone ligands: Synthesis, characterization, crystal structures, and antibacterial activity

Abstract

A pair of structurally similar dioxomolybdenum(VI) complexes with general formula [MoO₂(L)(MeOH)] (L = L¹ = N’-(3,5-dibromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide for I, L = L² = N’-(3,5-dibromo-2-hydroxybenzylidene)-2-methylbenzohydrazide for II), have been prepared and characterized by elemental analysis, IR spectra, and single crystal X-ray determination (CIF files CCDC nos. 917823 (I) and 917824 (II)). The hydrazone ligands coordinate to the Mo atoms through phenolate oxygen, imine nitrogen, and enolic oxygen atoms. The Mo atom in each complex is six-coordinated in an octahedral geometry. The crystals of the complexes are stabilized by hydrogen bonds. The complexes and the ligands were assayed for antibacterial activities against three Gram-positive bacterial strains (B. subtilis, S. aureus, and S. faecalis) and three Gram-negative bacterial strains (E. coli, P. aeruginosa, and E. cloacae) by MTT method. As a result, the complexes showed effective antimicrobial activity against the microorganisms tested.