Synthesis of Some Organometallic Complexes of Ti(IV)/Zr(IV) Involving Sulfur Containing Schiff Base Ligands: Spectral, Electrochemical, Surface Morphology, and Antimicrobial Studies

Abstract

The reactions of bis(cyclopentadienyl)titanium(IV)/zirconium(IV) dichloride with Schiff base derived by condensing thiophene-2-carboxaldehyde (tc), pyridine-2-carboxaldehyde (pc), and 5-methylthiophene-2-caroxaldehyde (mtc) with sulfamethoxazole (sm) have been studied in refluxing tetrahydrofuran under nitrogen atmosphere. The complexes of the type [Cp 2 MCl(L)]Cl (L D tc-sm, pc-sm, and mtc-sm; M D Ti/Zr) have been isolated and have been characterized using elemental analyses, molar conductance, mass, 1 H NMR, 13 C NMR, IR, UV-Vis, CV, TGA, powder XRD, and SEM. The results show that the Schiff base ligands are coordinated to the metal ions in a bidentate manner. Antimicrobial studies were conducted to assess growth inhibition potential of complexes and ligands against various fungal and bacterial strains.

Thiophene‐containing compounds with antimicrobial activity

“…Thiophene-2-carboxaldehyde and its 5-methyl-substituted analog were also condensed with sulfamethoxazole and the resulting Schiff bases were employed as ligands in the preparation of metallocene-derived complexes 230 (Figure 27). [207] The activity of these ligands and complexes against five bacterial strains and five fungal strains was determined using paper discs that were dipped in the solutions of the test compounds (1000 ppm in DMF) and were compared to the activity of ampicillin. Generally, the complexes were slightly less active than the corresponding ligands and compound 230…”

“…Thiophene‐2‐carboxaldehyde and its 5‐methyl‐substituted analog were also condensed with sulfamethoxazole and the resulting Schiff bases were employed as ligands in the preparation of metallocene‐derived complexes 230 (Figure 27). [ 207 ] The activity of these ligands and complexes against five bacterial strains and five fungal strains was determined using paper discs that were dipped in the solutions of the test compounds (1000 ppm in DMF) and were compared to the activity of ampicillin. Generally, the complexes were slightly less active than the corresponding ligands and compound 230 (R = H) derived from the Schiff base of thiophene‐2‐carboxaldehyde were slightly more active (diameter of inhibition zone was half of that measured for ampicillin) than complexes 230 obtained from the Schiff base of 5‐methylthiophene‐2‐carboxaldehyde (diameter of inhibition zone was one‐third of that measured for ampicillin).…”