Synthesis, characterization, X‐ray structure, DNA binding, antioxidant and docking study of new organotin(IV) complexes
Shaista Ramzan, Shahnaz Rahim, Syed Tasleem Hussain, Katherine B. Holt, Jeremy K. Cockcroft, Niaz Muhammad, Ziaur Rehman, Asif Nawaz, Shaukat Shujah
Abstract
Four new diorganotin(IV) complexes, including Me 2 SnL( 1 ), Bu 2 SnL( 2 ), Ph 2 SnL( 3 ) and Oct 2 SnL( 4 ), were synthesized by reacting R 2 SnCl 2 (where R = Me, Bu, Ph, Oct) with N ′‐(3,5‐dichloro‐2‐hydroxybenzylidene)‐2‐phenylacetohydrazide H 2 L . The synthesized ligand and complexes were structurally characterized by various techniques, including Fourier transform infrared (FT‐IR), 1 H and 13 C 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 × 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, ∆H, ∆G and ∆S, were also calculated. The DPPH antioxidant results showed that complex 2 is an active antioxidant.