Synthesis, characterization, X-ray structure, DNA binding, antioxidant and docking study of new organotin(IV) complexes

Four new diorganotin(IV) complexes, including Me2SnL(1), Bu2SnL(2), Ph2SnL(3) and Oct(2)SnL(4), were synthesized by reacting R2SnCl2 (where R = Me, Bu, Ph, Oct) with N '-(3,5-dichloro-2-hydroxybenzylidene)-2-phenylacetohydrazide H2L. The synthesized ligand and complexes were structurally characterized by various techniques, including Fourier transform infrared (FT-IR), H-1 and C-13 nuclear magnetic resonance (NMR) and mass spectrometry. The data suggested that tin-oxygen and tin-nitrogen bonds are formed during complex formation, confirming the coordination of ligand with dialkyltin(IV) moieties and the presence of penta-coordinated structures. The single-crystal X-ray study was performed to confirm the molecular structure of complex 1, which revealed that the molecular structure is distorted towards square pyramidal geometry. The compound-DNA interaction was investigated via spectroscopic, electrochemical and molecular docking studies; the mode of interaction found in all cases was intercalative in nature. The complex 3 showed the highest binding ability with sodium salt of salmon sperm DNA (SS-DNA) (1.93 x 10(5) M-1). The data obtained for DNA interaction studies from theoretical calculation via docking studies match well with those observed from spectroscopic and electrochemical analyses. Electrochemical and thermodynamic parameters, including diffusion coefficient, increment H, increment G and increment S, were also calculated. The DPPH antioxidant results showed that complex 2 is an active antioxidant.

Automated summary

In this study, four new diorganotin(IV) complexes were synthesized and their structures were characterized by various techniques including FT-IR, H-1 NMR, C-13 NMR, and mass spectrometry. The results confirmed the formation of tin-oxygen and tin-nitrogen bonds during complex formation, as well as the presence of penta-coordinated structures. The interaction between the complexes and DNA was found to be intercalative in nature, and the binding ability of complex 3 with SS-DNA was the highest. The electrochemical and thermodynamic parameters were also calculated, and complex 2 showed significant antioxidant activity.