Synthesis and X-ray Structures of Tin(IV) and Lead(II) Complexes with Heterocyclic Thiones

Tin(IV) and lead(II) complexes of 3‐(trifluoromethyl)pyridine‐2‐thione (3‐CF3‐pySH) and 5‐(trifluoromethyl)pyridine‐2‐thione (5‐CF3‐pySH) have been synthesised. The compounds [Sn(3‐CF3‐pyS)4] (1), [Sn(5‐CF3‐pyS)4] (2), [Pb(3‐CF3‐pyS)2] (3), and [Pb(5‐CF3‐pyS)2] (4) were obtained by addition of the appropriate ligand to a methanol solution of tin(II) chloride or lead acetate in the presence of triethylamine. The complex [Sn(5‐CF3‐pyS)4] was also prepared by electrochemical oxidation of a tin anode in a cell containing an acetonitrile solution of the ligand 5‐(trifluoromethyl)pyridine‐2‐thione. The X‐ray crystal structure of [Sn(3‐CF3‐pyS)4] reveals a dodecahedral coordination geometry around SnIV, with the four thionate ligands acting in a bidentate (N,S) manner. [Sn(5‐CF3‐pyS)4] also consists of monomeric neutral molecules with the tin(IV) atom in an octahedral geometry with two bidentate (N,S) ligands and two monodentate S ligands. The molecular structure of [Pb(3‐CF3‐pyS)2] shows the metal in a five‐coordinate geometry with the stereochemically active lead(II) lone pair in an equatorial position of a trigonal bipyramid. Spectroscopic data for the complexes (IR, NMR, FAB, and Mössbauer spectra) are discussed and related to the structural information. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)