Synthesis, Physicochemical Studies and Powder X‐Ray Diffraction Analyses for New Niclosamide Metal Complexes with Significant Bioactive Behavior

Abstract This work underlines some important features for the research on metal complexes of Niclosamide as antioxidants and antimicrobial evaluation of some of these compounds as possible therapeutic agents. Niclosamide metal complexes show a significant leap in the study of antibiotic resistance bacteria including Methicillin Resistant S.aureus (MRSA). The synthesized metal complexes of niclosamide in our current innovation are highly effective at eliminating this destructive sort of bacteria. Niclosamide metal complexes were synthesized then characterized by elemental analysis, Infra‐Red, electronic spectra, magnetic susceptibility, Mass spectra and ESR spectra of Cu (II) complex to know their geometries and mode of bonding, with stoichiometry, 1 : 1 (M : L). All the Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) metal ions complexes were proposed to be with distorted octahedral geometry. Powder X‐Ray Diffraction technique is being utilized to further investigation of synthesized Niclosamide metal complexes. Expo2014 software was also employed to solve the structure of these novel complexes which proven the distortion of crystal structure. The TGA and DTA curves were employed to derive the kinetic thermodynamic parameters. The thermal decomposition of the complexes ended with the formation of divalent metal oxide, MO or trivalent, M 2 O 3 as a final product except in case of Hg complex. The results of the antimicrobial activity of tested new metal complexes compounds exhibited potent antibacterial and antifungal activities in comparison to the Niclosamide ligand as reference. Quantum chemical parameters were estimated and provided noticeable values which completely matched with antimicrobial results that [Mn(NIC)(Cl 2 )(H 2 O) 2 ] ⋅ 0.4H 2 O has higher biological activity than ligand and other novel complexes. low concentration value of MIC results by 125 μg/ml for both niclosamide (NIC) complexes [Ni(NIC)(Cl 2 )(H 2 O) 2 ] and [Cu(NIC)(Cl 2 )(H 2 O) 2 ] ⋅ 2.5H 2 O with Methicillin Resistant S.aureus (MRSA) genus maybe a valuable data used to produce novel therapeutic agent. Depending on their structure and on the source of the oxidative stress, metal complexes of Niclosamide might act as antioxidants or pro‐oxidants.