Homobimetallic organotin(IV) complexes with hexadentate Schiff base: Synthesis, crystal structure and antimicrobial studies

• Synthesis of four new homobimetallic bis[diorganotin(IV)] complexes.
• Spectroscopic characterization by FT-IR, 1H, 13C and 119Sn NMR spectroscopy.
• NMR studies indicate pentacoordinated tin centers.
• Single crystal X-ray analysis confirms the homobimetallic nature of complexes.
• The coordination geometry around each tin atom is distorted square pyramidal.

This article describes the synthesis of four new homobimetallic organotin(IV) complexes: [Et2Sn]2L (1), [Bu2Sn]2L (2), [Oct2Sn]2L (3) and [BuClSn]2L (4) (H4L = N1′,N6′-bis(5-bromo-2-hydroxybenzylidene)adipodihydrazide) and their structural elucidation by means of elemental analysis, mass spectroscopy, FT-IR, NMR (1H, 13C, 119Sn) and single crystal X-ray analysis. Spectroscopic studies indicate coordination of hexadentate ligand to the diorganotin(IV) moieties via ONO–ONO donor sites and pentacoordinated tin centers. Single crystal X-ray analysis of (1) and (2) revealed homobimetallic nature of complexes with each Sn atom in a distorted square pyramidal coordination geometry. Packing diagrams suggest the seminal role of Sn⋯N and Br⋯π interactions in generating supramolecular assembly. The synthesized compounds were screened for their antimicrobial activity and cytotoxicity. Compound (2) exhibit highest activity against several pathogenic microbes.

Four homobimetallic bis[diorganotin(IV)] complexes of general formula (R2Sn)2[(O)Br–C6H3CH2N2C(O)C4H8C(O)N2CH2C6H3Br(O)] have been synthesized by the interaction of diethyltin(IV) dichloride, dibutyltin(IV) dichloride, dioctyltin(IV) oxide, butyltin(IV) chloridedihydroxide and N1′,N6′-bis(5-bromo-2-hydroxybenzylidene)adipodihydrazide in toluene. Spectroscopic and single crystal X-ray studies confirm coordination of tetrabasic ligand to the diorganotin(IV) moieties via ONO–ONO donor sites and pentacoordinated tin.Figure optionsDownload as PowerPoint slide