Ladder-like diorganotin(IV) complexes containing cyclohexanecarboxylates: Synthesis, characterization and biological activities

Abstract

Reactions of the diorganotin(IV) dichlorides with cyclohexanecarboxylate ligands yielded four new dimeric ladder-like tetraorganostannoxanes formulated as [R4Sn2(C6H11COO)(μ3-O)(μ-OH)]2[R=Et (1), nBu (2), nOct (3) and Ph (4)]. All these complexes were characterized by elemental analysis, IR, NMR (1H, 13C, 119Sn) spectra and in one case by X-ray diffraction analysis. The crystal structure of 1 reveals the formation of the tetranuclear species contains a planar Sn4O4 core, consisting of three adjacent rhombs with bridging oxo and hydroxyl ligands. The central tin atoms are five-coordinated to assume a distorted trigonal bipyramidal configuration and the OH ligands act as monodentate O-bound planar. 2 exhibits good antitumor activity against KB cells (IC50=0.90μM) and 4 shows significant antibacterial activity against Gram-positive bacteria Staphylococcus aureus (MIC=0.147μg/ml), both being even higher than those of clinically used drugs.