Synthesis, structures, antioxidant, and antifungal activities of organotin(IV) complexes derived from 1-(3′-carboxyphenylhydrazono)naphthalene-2-one

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 [RxSnIV(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 Me2SnIVO5. 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.</p