Diphenyltin(IV) complexes of the 5-[(E)-2-(aryl)-l-diazenyl]quinolin-8-olates:: Synthesis and multinuclear NMR, 119Sn Mossbauer, electrospray ionization MS, X-ray characterization and assessment of in vitro cytotoxicity

A series of cis-bis {5-[(E)-2-(aryl)-1-diazenyl]quinolinolato} diphenyltin(IV) complexes have been synthesized and characterized by H-1, C-13, Sn-119 NMR, ESI-MS, IR and Sn-119m Mossbauer spectroscopic techniques in combination with elemental analysis. The structures of a ligand (LH)-H-6 (i.e., 5-[(E)-2-(4-ethoxyphenyl)-1-diazenyl]quinolin-8-ol) and three diphenyltin(IV) complexes, viz., Ph2Sn(L-1)(2)center dot(CH3)(2)CO (1), Ph2Sn(L-4)(2) (4) and Ph2Sn(L-5)(2) (5) (L = 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-ol: aryl = phenyl - ((LH)-H-1); 4'-methylphenyl - ((LH)-H-4) and 4'-bromophenyl - ((LH)-H-5)) were determined by single crystal X-ray diffraction. In general, the complexes were found to adopt a distorted cis-octahedral arrangement around the tin atom. These complexes retain their solid-state structure in non-coordinating solvent as evidenced by Sn-119 NMR spectroscopic results. The in vitro cytotoxicity of 1 is reported and compared with Ph2Sn(OX)(2) (Ox = deprotonated quinolin-8-ol) against seven well characterized human tumor cell lines. (c) 2005 Elsevier B.V. All rights reserved.