DMSO coordinated dioxidomolybdenum(VI) complexes chelated with 3-methoxybenzhydrazone related ligands: Synthesis, structural studies and in vitro cytotoxicity

Three new DMSO coordinated dioxidomolybdenum(VI) complexes [MoO2L3OMe(DMSO)] (1), [MoO2L4OMe(DMSO)] (2) and [MoO2L5OMe(DMSO)] (3) (where, L-3OMe = 2-oxy-3-methoxybenzaldehyde-3-methoxy-benzhydrazonato, L-4OMe = 2-oxy-4-methoxybenzaldehyde-3-methoxybenzhydrazonato and L-5OMe = 2-oxy-5-methoxybenzaldehyde-3-methoxybenzhydrazonato) (Scheme 1) were synthesized by reacting [MoO2(acac)(2)] with the corresponding aroylhydrazone in presence of the solvent, DMSO and fully characterized. The various characterization techniques included elemental analysis, spectroscopic techniques (IR, electronic and H-1 NMR), thermogravimetric analysis and cyclic voltammetry. The molecular and crystal structures of 1, 2 and 3 were determined by single crystal X-ray diffraction method. In all complexes, the molybdenum atom displays a distorted octahedral geometry. In addition, the discussion on coordination geometries and non-covalent interactions were also supported using Hirshfeld surface analysis. The in vitro cytotoxicity of the aroylhydrazone ligands and their molybdenum complexes against lymphoma ascites cell line demonstrated that the complexes are more cytotoxic than their corresponding ligands. (C) 2019 Elsevier Ltd. All rights reserved.