Integrated Experimental and Theoretical Studies of Organotin(IV)‐Hydrazone Complexes: Synthesis, Structural Elucidation, Computational Insights, and Antimicrobial Activity

ABSTRACT In the search of some new therapeutic agents against microbial infections, a series of pentacoordinated diorganotin(IV) complexes [R 2 SnL 1–2 ] were prepared by reacting 2‐(4‐chloro‐2‐methylphenoxy)acetohydrazide and 3‐ethoxy/5‐nitrosalicylaldehyde with R 2 SnCl 2 (R = Me, n ‐Bu, Et, Ph). Various spectral techniques, including NMR ( 1 H, 13 C, 119 Sn), FT‐IR, and HRMS, confirmed their pentacoordinated geometry of complexes, further validated by single‐crystal x‐ray diffraction (SC‐XRD) analysis of complex 3 [Me 2 SnL 1 ] that displays monoclinic crystal system with a deformed square‐pyramidal geometry around the tin metal center, with two methyl groups, N azomethine , O phenolic , and O enolic atoms. Furthermore, the antimicrobial study shows that all synthesized compounds ( 1–10 ) exhibit significant activity against microbial infections. Among them, complexes 6 and 10 demonstrated the highest efficacy. Findings confirmed that the biological activity of complexes surpasses that of ligands ( 1, 2 ) itself, with complex 6 [Ph 2 SnL 1 ] demonstrating highest efficiency in controlling microbial infections with minimum inhibitory concentration (MIC) values of 0.0049 µmol/mL against Candida albicans and Escherichia coli and comparable to standard drugs such as ciprofloxacin and fluconazole. To validate the enhanced antimalarial potential of the ligand 1 and its complexes ( 3–6 ), density functional theory (DFT) calculations were performed on all synthesized compounds.