David G. Calatayud - Diphenyllead(IV) Chloride Complexes with Benzilthiosemicarbazones. The First Bis(Thiosemicarbazone) Derivatives

Version 1

      Publication Details (including relevant citation   information):

      Calatayud, D G, Lopez-Torres, E, Mendiola, M A Inorganic   Chemistry 2007 46 (24) 10434-10443

      Abstract: Reactions of diphenyllead(IV) chloride   with benzil bis(thiosemicarbazone) (L1H6) and benzil   bis(4-methyl-3-thiosemicarbazone) (L1Me2H4) afforded the first   complexes containing the diphenyllead(IV) moiety with   bis(thiosemicarbazone) ligands. The new complexes show diverse   structural characteristics depending on the ligand and the   working conditions. Complexes [PbPh2Cl(L1H5)]·3H2O (1) and   [PbPh2Cl(L1Me2H3)] (3) are mononuclear species in which the   ligands are partially deprotonated and the lead atom has a   C2N2S2Cl environment in a distorted pentagonal bipyramid   coordination geometry. Complex [PbPh(L1Me2H2)]2·2H2O (4) was also   obtained, which contains two lead atoms in a binuclear structure   with a C2N2S3 coordination sphere for each lead atom, since both   dideprotonated ligands act as N2S2 chelate and as sulfur bridge.   Reaction from L1H6, in the same conditions in which complex 4 was   prepared, gave a mixture of products: the lead (II) complex   [Pb(L1H4)]2 (2) and [PbPh3Cl]n. Reactions with the cyclic   molecules   5-methoxy-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]-triazine-3-thione   (L2H2OCH3) and   5-methoxy-4-methyl-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]-triazine-3-thione   (L2MeHOCH3) were also explored. In all the complexes, the ligands   are deprotonated. The complexes [PbPh2(L2)2] (5) and   [PbPh2(L2MeOCH3)2] (7) present the same characteristics. The   X-ray structure of 5 shows a distorted octahedral geometry around   the lead atom, with the ligand molecules acting as NS chelates,   but the nitrogen bonded to the metal is different; one of the   triazines shows a novel behavior, since the nitrogen atom of the   new imine group formed is the one that is bonded to the lead   center, being a good example of linkage isomerism. The complex   [PbPh2Cl(L2)] (6), which was also isolated, could not be   crystallized. All the complexes were characterized by elemental   analysis, mass spectrometry, IR and 1H, 13C, and 207Pb NMR   spectroscopy and some of them by X-ray diffraction studies.

      Address (URL): http://dx.doi.org/10.1021/ic701490j