Innovation of Some Novel Complexes Based on <i>N</i>‐[(Ethylcarbamothioyl)amino]‐<i>1</i>‐(hydrazine Carbonyl)formamide (L²) and (L³) <i>N,N′</i>‐Bis‐[(ethylcarbamothioyl)amino]ethane Diamide Ligands: Synthesis, Structural Elucidation, DFT Calculations, and Biological Studies

Abstract

ABSTRACT Different chelates derived from, N ‐[(ethylcarbamothioyl)amino]‐ 1‐ (hydrazinecarbonyl)formamide ( L 2 ) and N,N′‐ bis‐[(ethylcabomothioyl)amino]ethanediamide ( L 3 ), with metal ions were synthesized and characterized by elemental analyses, spectral (IR, UV–Vis, 1 H NMR, 13 C NMR, and mass), TGA, and magnetic measurements. The two new ligands ( L 2 and L 2 ) were synthesized using L 1 (oxalic acid dihydrazide [ ODH ]). Theoretical studies and molecular docking calculations were investigated. IR spectra suggest that L 2 behaves in a bidentate manner coordinating either via the carbonyl oxygen and the nitrogen atom of the hydrazine group and/or through the sulfur (C=S and/or C–S) and the NH groups. In the case of L 3 , the metal complexes were obtained in the enol form with the removal of proton or more from either the carbonyl (C=O) and/or thioketo (C=S) or both groups after enolization is occurred, except the Pd 2+ , which was isolated in the keto form without removal of hydrogen atoms. The computational estimation of L 2 , and L 3 and their complexes were approved with the Gaussian 09 W program in DFT/B3LYP. DPPH and ABTS were tested against two free radical scavengers that were utilized in order to evaluate the antioxidant potential of complexes in vitro. Biological effectiveness of L 2 and L 3 and their complexes against Gram‐positive and Gram‐negative bacteria was in vitro investigated. Antifungal action was investigated utilizing inhibition zone diameter. Moreover, the ligands and its complexes were exhibited a broad spectrum of DNA degradation effects, as measured by agarose gel electrophoresis. The antioxidant activity of the complexes was determined based on the radical scavenging ability in reacting with a stable DPPH . Wound healing assay was tested with the most active complexes against liver cancer cell line HepG‐2.