Synthesis, spectroscopy, single crystal XRD and biological studies of multinuclear organotin dicarboxylates

Multinuclear organotin(IV) dicarboxylates of the general formula (Me3Sn)2L·H2O (1), (Ph3Sn)2L (2) and Me2SnL[Sn(Cl)2Me2]2 (3) were synthesized by refluxing disodium iminodiacetate hydrate (Na2L·H2O) with Me3SnCl/Ph3SnCl/Me2SnCl2 in methanol. The elemental analysis (C, H and N) data agreed well with the chemical compositions of the products. IR spectroscopy demonstrated a bridging coordination mode of the carboxylate group. 1H NMR spectroscopy suggested a penta-coordinated environment around the tin(IV) center in complexes 1 and 3. The title complex 3 represents one of the very few examples of organotin(IV) carboxylates showing simultaneously coordination with dimethyltin(IV) as well as dichlorodimethyltin(IV) moieties, by substitution and addition reactions, respectively. The 13C NMR spectroscopy demonstrated the carboxylate-metal linkages. EIMS and ESI spectra verified the molecular skeletons of the products 1–3. Thermogravimetric analysis revealed the bimetallic nature of 2. A single crystal XRD study of 3 has shown a predominantly square pyramidal geometry with some trigonal bipyramidal characteristics around each metal center. The novel products exhibited antibacterial/antifungal potential and their minimal inhibitory concentrations (MIC) were also evaluated. In vitro hemolytic studies on human red blood cells indicated a slightly toxic nature of the synthesized complexes.

Multinuclear organotin(IV) dicarboxylates were synthesized and characterized using disodium imminodiacetate hydrate as a precursor. The complexes show a penta-coordinated geometry about each tin center in the solid and solution states. The complexes exhibit antibacterial/antifungal potencies, with some hemolytic effects.Figure optionsDownload as PowerPoint slide