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

Multinuclear organotin(IV) dicarboxylates of the general formula (Me3Sn)(2)L center dot H2O (1), (Ph3Sn)(2)L (2) and Me2SnL[Sn(Cl)(2)Me-2](2) (3) were synthesized by refluxing disodium iminodiacetate hydrate (Na2L center dot 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. H-1 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 dichlorodi-methyltin(IV) moieties, by substitution and addition reactions, respectively. The C-13 NMR spectroscopy demonstrated the carboxylate-metal linkages. ELMS 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. (C) 2016 Elsevier Ltd. All rights reserved.