Abstract
•M.Mof.His·nH2O nanostructured complexes were synthesized and characterized.•DFT calculations validate the experimental data.•Photocatalytic study of complexes against methylene blue under UV light was done.•Photodegradation was explained using band gap calculations implementing DOS and PDOS through DFT calculations.
Moxifloxacin Histidine mixed ligand (MHL) metal complexes of the M.Mof.His·nH2O 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 1HNMR 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.