6928-68-3Relevant articles and documents
Molecular and supramolecular structures of 1-phenyl-4-phenylacetyl-2- thiosemicarbazide (H2L) and its complexes with diphenyllead(IV) chloride and acetate
Casas,Castellano,Ellena,Garcia-Tasende,Sanchez,Sordo,Touceda
, p. 2247 - 2252 (2005)
Reaction of 1-phenyl-4-phenylacetyl-2-thiosemicarbazide (H2L) with diphenyllead(IV) dichloride and acetate afforded the complexes [PbPh 2Cl2(H2L)2] and [PbPh2L]. The ligand and the complexes were characterized by elemental analyses, 1H and 13C NMR spectroscopy and X-ray crystallography. In the asymmetric unit of crystals of the ligand there are four independent molecules of H2L and four molecules of water, which associate in the lattice as two independent sheets. The complex [PbPh2Cl 2(H2L)2]·4MeOH has slightly distorted all-trans octahedral geometry around the lead atom, and the fact that the ligand is S-bound rather than O-bound suggests that PbPh2Cl2 behaves as a "soft" Lewis acid. Hydrogen bonds involving NH groups, Cl atoms and MeOH molecules form a three-dimensional supramolecular structure. In [PbPh2L]·Me2CO, the L2- anion bridges between two metal centres, binding to one strongly via the N and S atoms and weakly via the O atom, and to the other via the O atom, thus creating polymeric chains along the b axis. The double deprotonation and metallation of H 2L induce significant changes in its configuration and lengthen the C-S and C-O bonds, suggesting an evolution of the dianion towards a thiol-enol form.
New insights on the Lewis acidity of diorganolead(IV) compounds: Diphenyllead(IV) complexes with N,O,S-chelating ligands
Casas, José S.,Castellano, Eduardo E.,Ellena, Javier,García-Tasende, María S.,Sánchez, Agustín,Sordo, José,Touceda, ángeles
, p. 1 - 11 (2008)
The reactions of PbPh2(OAc)2 with alkylglyoxylate thiosemicarbazones (HRGTSC, R = Et, Bu) afforded complexes of the type [PbPh2(GTSC)] · H2O, [PbPh2(RGTSC)2] and [PbPh2Cl(BuGTSC)]. The structures of HRGTSC (R = Me, Et, Bu), [PbPh2(OAc)(RGTSC)](R = Me, Et, Bu), [PbPh2Cl(BuGTSC)] and [PbPh2(GTSC)] · H2O have been studied by X-ray diffraction. [PbPh2(OAc)(RGTSC)] and [PbPh2(GTSC)] · H2O have [PbC2NO3S] kernels and the coordination sphere of the metal is pentagonal bipyramidal. [PbPh2Cl(BuGTSC)] has a [PbC2NOSCl] kernel and the coordination geometry around lead is pentagonal bipyramidal with one vacant site. Analysis of the bond distances in [PbPh2(GTSC)] · H2O suggests a significant affinity between diphenyllead(IV) and carboxylate donor groups, supporting a borderline acidic character for this organometallic cation. 1H and 13C NMR spectra in DMSO-d6 suggest the partial dissociation of the acetate in [PbPh2(OAc)(RGTSC)] solutions and indicate some differences in the coordination mode of the two RGTSC- ligands in [PbPh2(RGTSC)2] complexes.
Methyllead(IV) derivatives stabilized by DAPTSC2-: Synthesis and structures of new diorganolead(IV) complexes
Casas, Jose S.,Castellano, Eduardo E.,Ellena, Javier,Garcia-Tasende, Maria S.,Namor, Facundo,Sanchez, Agustin,Sordo, Jose,Vidarte, Maria J.
, p. 3742 - 3750 (2008/03/14)
The reaction of the bis(thiosemicarbazone) of dimethyl pyridine-2,6-diyl diketone, H2DAPTSC, with PbMe2(OAc)2, PbMePh(OAc)2 or PbPh2(OAc)2 in MeOH afforded the complexes [PbMe2(DAPTSC)], [PbMePh(DAPTSC)] or [PbPh 2-(DAPTSC)] (in the first two cases together with [Pb(DAPTSC)]). X-ray crystallography of the Pb(IV) complexes showed that the metal has a pentagonal bipyramidal coordination sphere. The N3,S 2-bound DAPTSC2- anion occupied the eguatorial plane and the organic groups were in the apical positions. These compounds retain the same coordination mode in DMSO solution. DAPTSC2- is also N 3,S2-bound in [Pb(DAPTSC)], a complex with a stereochemically active PbII lone pair. The reaction of PbPh 2Cl2 with H2DAPTSC, also in methanol at room temperature, afforded [PbPh2(H2DAPTSC)] 2[PbPh2Cl4]Cl2·6CH 3OH. X-ray crystallography of this centrosymmetric complex showed it to consist of two [PbPh2(H2DAPTSC)]2+ cations of similar structure to the neutral [PbR2(DAPTSC)] complexes, together with a trans-octahedral [PbPh2Cl4]2- anion and two Cl- anions. This compound decomposes in DMSO solution, probably evolving to H2DAPTSC and PbPh2Cl 2(DMSO)n. In order to evaluate the changes undergone by H2DAPTSC under metallation, the X-ray structure of the free molecule was also determined. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Reaction of Arylboronic Acids and their Derivatives with Lead Tetra-acetate. The Generation of Aryl-lead Triacetates, and meta- and para-Phenylenebis(lead triacetate), in situ for Electrophilic Arylation
Morgan, Jacqueline,Pinhey, John T.
, p. 715 - 720 (2007/10/02)
Arylboronic acids and some of their derivatives have been found to undergo a rapid boron-lead exchange with lead tetra-acetate.In the presence of a catalytic amount of mercury(II) acetate, the reaction produces mainly the aryl-lead triacetate, and it has been developed as a convenient method for in situ generation of these useful electrophilic C-arylating reagents.The reaction allows the generation for the first time of meta- and para-phenylenebis(lead triacetate), compounds which behave as meta- and para-phenylene dication equivalents.
UEBER POLYPLUMBANE. I. ASYMMETRISCH SUBSTITUIERTE DIPLUMBANE
Kleiner, Norbert,Draeger, Martin
, p. 323 - 342 (2007/10/02)
Diplumbanes Pb2R3R'3 (R,R'=Ph, o-Tol, p-Tol) have been synthesized from R3PbLi and R'PbCl at -60 deg C in THF.Mass, 13C and 207Pb NMR spectra of the products exhibit migrations of R, R' in the transition state (R3PbLi + ClPbR'3) leading to a complex distribution of the substituents (δ(207Pb) with respect to PbMe4 -70 to -95 ppm).The Pb-Pb stretching vibration (100 to 115 cm-1) couples with a lattice vibration giving rise to a single intensive Raman line.The crystal structure of Pb2Ph3(p-Tol)3 has been determined and refined to R=0.155.Two independent molecules are disordered and have identical distribution of the substituents Ph(p-Tol)2Pb-PbPh2(p-Tol) (distances Pb-Pb 283(2) and 286(1) pm).Products Pb2Ph3(OAc)3 with a Pb-Pb bond, already discussed in the literature, could not be verified.
