Mono-aryltin(IV) and mono-benzyltin(IV) complexes with pyridine-2-carboxylic acid and 8-hydroxyquinoline. X-ray structure of p-chloro-phenyl-tris(8-quinolinato)tin(IV)-2CHCl3

Article abstract of DOI:10.1016/S0022-328X(99)00103-5

Complexes RSn(O₂CPy)₃·2H₂O and RSn(Ox)₃, (PyCOOH = pyridine-2-carboxylic acid, HOx = 8-hydroxyquinoline, R = o- and p-Tolyl, o- and p-ClC₆H₄ = o- and p-ClPh, o-ClC₆H₄CH₂ = o-ClBenzyl; besides, R = Ph in RSn(Ox)₃) have been synthesized and characterized by elemental analysis and determination of molecular weights in CHCl₃ solutions. The structure of p-ClPh-Sn(Ox)₃·2CHCl₃ has been determined by X-ray diffractometry. The 7-coordinated tin atom of the monomeric compound is in the center of a pentagonal bipyramid formed by (p-ClPh)C and O and N atoms of the chelating Ox^- ligands. The latter type of structure would hold for all complexes according to ¹¹⁹Sn Moessbauer (including the determination of the dynamics of ¹¹⁹Sn nuclei) and IR spectroscopy in the solid state; the ligand ^-O₂CPy appears to chelate Sn through one oxygen atom of the -COO^- group and the N atom, although the occurrence of one chelating and two monodentate PyCO^-₂ ligands (through -COO^-), and coordination by the H₂O molecules to Sn cannot be excluded. In CDCl₃ and CHCl₃ solutions, the persistence of the pentagonal bipyramidal species is assumed, in line with ¹H-, ¹³C-, ¹¹⁹Sn-NMR and UV-vis spectroscopic studies.