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

Abstract

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.

Keywords:

• Organotin(IV) compounds
• crystal structures
• NMR spectroscopy
• antioxidant
• antifungal agent

Supplementary material

CCDC numbers 2149882 for 1 and 2149882 for 3 have crystallographic supplementary data and can be obtained free of charge from http://www.ccdc.cam.ac.uk/conts/retrieving.html, or the Cambridge Crystallographic Data Center, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: [phone]; or E-mail: [email protected]. As included in the supplementary data, the IR spectra are in Figure S1 for 1, Figure S2 for 2 and Figure S3 for 3. Figures S4, S5 and S6 are the ¹H NMR spectra of the compounds: ligand, 1 and 3, respectively. The ¹³C NMR spectra of 1, 2 and 3 are in Figures S7, S8 and S9, respectively. The antioxidant and antifungal results are tabulated in Tables S1 and S2, respectively.

Acknowledgments

We thank Department of Chemistry, NIT Agartala for providing research facilities. PB is grateful to NIT Agartala for receiving institutional fellowship from MHRD, Govt. of India. We also thank IIT Madras for single crystal X-ray diffraction and data analysis.

Disclosure statement

All authors declare that there are no conflicts of interests on this research work.