Supramolecular homobimetallic <Emphasis Type="Italic">bis</Emphasis>-diorganotin(IV) complexes of ditopic oxygen nitrogen donor ligand: synthesis,spectroscopic characterization,crystal structure and biological screening

Six new homobimetallic bis-diorganotin(IV) complexes: Me₂Sn]₂L (1), Et₂Sn]₂L (2), n-Bu₂Sn]₂L (3), Ph₂Sn]₂L (4), Oct₂Sn]₂L (5) and n-BuClSn]₂L (6) (H ₄ L=N¹′, N⁶′-bis(2-hydroxybenzylidene)adipodihydrazide) have been synthesized and structurally characterized by means of elemental analysis, mass spectroscopy, FT-IR, NMR (¹H, ¹³C{¹H}, ¹¹⁹Sn) and single-crystal X-ray diffraction. Spectroscopic studies indicate coordination of the ligand to the diorganotin(IV) moieties via iminolic oxygen, nitrogen and phenolic oxygen atoms generating pentacoordinated tin centers. Single-crystal X-ray analysis of (1) revealed homobimetallic nature of complex with dimethyltin moieties oriented in trans-conformation. The ligand is non-planar with each Sn atom in a distorted square pyramidal coordination geometry. Packing diagrams suggest the essential role of C–H^…N and C–H^…O interactions in generating supramolecular assembly. The ligand and complexes were screened for in vitro antimicrobial activity and cytotoxicity. Compound (4) exhibits highest cytotoxicity.