Isostructural metal hydrazones of 2-(methoxycarbonyl-hydrazono)-pentanedioic acid, H2L: Synthesis, cytotoxic activity of nano spinel ZnCo2O4 derived from single source precursor, [Zn1/3Co2/3(HL)2]·3H2O

Abstract

Metal Schiff base [2-(methoxycarbonyl-hydrazono)-pentanedioic acid, H2L] complexes of type [M(HL)2]·3H2O, where M = Co (1), Zn (2) & Co-Zn (3), have been synthesized by condensation of α-ketoglutaric acid and methyl carbazate in the presence of divalent metal ions. A stoichiometric reaction of the Schiff base ligand with metal ions resulted in a solid solution precursor of [Zn1/3Co2/3(HL)2]. The crystal structures of metal and mixed metal (Zn-Co) complexes were isostructural and crystallized in monoclinic systems. The synthesized solid solution was employed as a precursor for preparing zinc cobaltite spinel (ZnCo2O4) nanoparticles. As-synthesized nanospinel cobaltite was characterized using Fourier-Transform Infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and transmission electron microscopy (TEM) techniques. PXRD indicated that the product had a spinel type structure with high purity and a crystalline nature. The TEM images show that the spinels were constructed via self-assembled agglomeration of nanoparticles with irregular shapes. The elemental compositions and oxidation states of as-prepared ZnCo2O4 were further analyzed by X-ray photoelectron spectroscopy (XPS). Further, the cytotoxicity was determined against human breast adenocarcinoma (MCF-7) cancer cell lines at different concentrations using a thiazolyl blue tetrazolium bromide (MTT) assay. The spinel oxides prepared from the precursors showed promising results, demonstrating their clinical importance.