Synthesis, characterization, thermal, DFT computational studies and anticancer activity of furfural-type schiff base complexes

Abstract

Novel Schiff base ligand N1,N2-bis(furan-2-ylmethylene)-4-methylbenzene-1,2-diamine (L) has been synthesized. The metal complexes of L with metal ions of silver (I), chromium (III), iron (III), cobalt (II), copper (II), cadmium (II), mercury (II), and uranium (VI) were investigated using various spectroscopic techniques (FT-IR, 1H NMR, UV, mass), elemental analysis, TGA, conductivity, X-ray diffraction, fluorescence, and magnetic susceptibility measurements. The conductivity measurements showed the electrolytic nature of the complexes except for Co(II), Cu(II), and Hg(II) complexes. Octahedral geometry was proposed for all complexes except Ag(I) complex that was observed as tetrahedral geometry based on the magnetic moment and spectral studies. The values of optical band gap energy (Eg) of the synthesized complexes and CdO (1.83–3.44 eV) suggested that these compounds could be used as semiconductors. The X-ray diffraction patterns of Schiff base and its complexes were investigated and nano-crystalline size was established for Ag(I), Cr(III), Fe(III), Co(II), Cu(II), and Cd(II) complexes. Theoretical calculations were carried out for the determination of the optimization geometry, vibrational frequencies, energy of HOMO and LUMO as well as the quantum chemical parameters for ligand and its Ag(I), Cr(III), Fe(III), Co(II), Cu(II) and Cd(II) complexes. Furthermore, the photocatalytic properties of the synthesized Fe2O3, Co3O4, CuO, and CdO nanoparticles for degradation of the methylene blue (MB) have been examined. The results showed that combined of H2O2 with catalyst increased the percent of degradation of MB to 83.29, 60.71, 73.70, and 77.24% in 90 min for the nanoparticles Fe2O3 (24 nm), Co3O4 (30 nm), CuO (35 nm), and CdO (74 nm), respectively, which is consistent with particle size. Antimicrobial screening confirmed that Cd(II) complex exhibited greater activity than both ligand and Gentamicin, the reference drug against both Gram-positive and E. coli bacterial strains. In addition, the Hg(II) complex displayed higher activity than both ligand and standard Ketoconazole against fungi. The cytotoxicity of the Cd(II) complex on Human liver carcinoma (Hep-G2) cells showed the highest potent cytotoxicity effect against the growth of carcinoma cells compared to the Vinblastine standard and the ligand.