Three new organotin(IV) complexes, [Me₃Sn(H₂L)]₂ (1), Bu₃Sn(H₂L) (2), and [(Bu₂Sn(H₂L))₂O]₂ (3) were synthesized by the reaction of 2-[4-hydroxy-3-((2-hydroxyethylimino)methyl)phenylazo]benzoic acid (H₃L) with appropriate alkyltin(IV) precursors. The complexes were characterized by elemental analysis, IR, and multinuclear (¹H, ¹³C and ¹¹⁹Sn) NMR spectroscopy. Further, the complex 1 was analyzed by single-crystal X-ray analysis. It displays a 24-membered cyclic dimeric Me₃Sn^IV(H₂L) unit where the ligand act as a bridging framework using its carboxylate-O and phenoxy-O atoms. The Sn(IV) adopts distorted trigonal-bipyramidal geometry. In the solution state, the structures were determined by ¹¹⁹Sn-NMR spectroscopy, and the complexes 1 and 2 have distorted tetrahedral geometry, whereas complex 3 shows distorted trigonal-bipyramidal geometry around the tin centres. The Hirshfeld surface analysis and DFT calculations, together with a topological analysis of the electron density distribution in the crystal structure of complex 1, indicate that its molecular packing determined by various noncovalent interactions, including stacking and hydrogen bonding. The antibacterial studies of the ligand and the complexes (1–3) against gram-negative bacteria viz. Klebsiella pneumoniae (A),Vibrio cholerae (M) and Shigella boydii (Q) and gram-positive bacteria viz.Staphylococcus aureus (J), Streptococcus pneumonia (K) are promising and the compounds can be treated as potential common antibacterial materials.

In this study, the hydrazone ligand 1-(3′-carboxyphenylhydrazono)naphthalene-2-one (H₂L) was employed to generate three new organotin(IV) compounds with the general formula of [R_xSn^IV(HL)_y] (where R = Me, x = y = 2 (1); R = n-Bu, x = 3, y = 1 (2), and R = Ph, x = 3, y = 1 (3)). The single-crystal structures of 1 and 3 were examined to establish the coordination environment about Sn(IV). Compound 1 possesses a hepta-coordinate homo-polymer with a chromophoric coordination environment of Me₂Sn^IVO₅. Compound 3, on the other hand, has monomeric distorted tetrahedral geometry with Ph₃SnO chromophoric unit. The ¹¹⁹Sn-NMR signals in the spectra of 1–3 are found to be at 145.5, 120.1, and −104.4 ppm, respectively, indicating that they are isostructural and adopt four-coordinate tetrahedral geometry in solution. The bioactivities of 1 and 3 among the three are distinct. The antioxidant activity of 1 in ethanol is the highest, with a 45.64% DPPH-scavenging efficiency, whereas 3 shows excellent antifungal efficacy against Penicilium chrysogenum, with a 21 mm inhibited zone at 750 μg/mL, which is significantly higher than that of standard drug amphotericin-B. Thus, the compounds could be treated as potential antioxidant and antifungal agents.