Synthesis and spectroscopic characterizations of nanostructured charge transfer complexes associated between moxifloxacin drug donor and metal chloride acceptors as a catalytic agent in a recycling of wastewater

Moxifloxacin Histidine mixed ligand (MHL) metal complexes of the M.Mof.His center dot nH(2)O type, where M are (Mg(II), Ca(II), Fe(III), and Zn(II)), Mof is moxifloxacin and His is a histidine amino acid, have been prepared. The MHL metal complexes could be synthesized using M(II/III): moxifloxacin: histidine amino acids in proportion of 1:1:1 in situ stereoselective chelation. The characterization of MHL complexes obtained have been done using elemental analyses, thermal analysis, spectroscopic and various techniques of physicochemical methods such as conductivity measurements, magnetic susceptibility, Electronic UV-Vis. absorption, infrared and (HNMR)-H-1 spectral studies. The magnetic susceptibility measurements at room temperature for these complexes are indicative of an octahedral geometrical structure except for zinc(II) complex has four coordination. Moxifloxacin and histidine ligands have a bidentate fashion through the oxygen atoms of carbonyl (quinolone) and carboxylic groups regarding Mof ligand and through the nitrogen and oxygen atoms of NH2 group and deprotonated carboxylic group regarding His secondary ligand. The catalytic degradation properties of metal complexes have been determined under UV light against methylene blue (MB) in aqueous solution. The results proposed that catalytic degradation toward MB in the presence of complexes of Mg(II), Ca(II), Fe(III) and Zn(II) are 33, 30, 81 and 51%, respectively, in 240 min. DFT studies using B3LYP/6-311G and lanL2DZ level of theory were used to obtain optimized geometry of synthesized metal complexes along with their electronic energy gap and MEP map. Also, the plausible mechanistic pathways by which metal complexes executed photodegradation have been explained with the aid of band gap calculations implementing density of states and partial density of states. (C) 2021 Elsevier B.V. All rights reserved.