Synthesis, crystal structure and biological activities of four novel tetranuclear di-organotin(IV) carboxylates

Four complexes: [Bu2(L1)SnOSn(L1)Bu2]2 (1), [Bu2(L2)SnOSn(L2)Bu2]2 (2), [Bu2(L3)SnOSn(L3)Bu2]2 (3), and [Bu2(L4)SnOSn(L4)Bu2]2 (4), (HL1 = 2-(4-methylbenzoyl)benzoic acid, HL2 = 2-(2,4-diethylbenzoyl)benzoic acid, HL3 = 2-(4-chlorobenzoyl)benzoic acid, HL4 = 2-(4-isopropylbenzoyl)benzoic acid) have been prepared and structurally characterized by means of elemental analysis and vibrational, 1H NMR and FT-IR spectroscopies. The crystal structures of all complexes have been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement. Each structure is centro-symmetric and features a central rhombus Sn2O2 unit with two additional tin atoms linked at the O atoms. Complex 1 exhibited good antibacterial and antitumor activities and have a potential to be used as drugs.