- Methyllead(IV) derivatives stabilized by DAPTSC2-: Synthesis and structures of new diorganolead(IV) complexes
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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.
- Casas, Jose S.,Castellano, Eduardo E.,Ellena, Javier,Garcia-Tasende, Maria S.,Namor, Facundo,Sanchez, Agustin,Sordo, Jose,Vidarte, Maria J.
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p. 3742 - 3750
(2008/03/14)
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- UEBER POLYPLUMBANE. I. ASYMMETRISCH SUBSTITUIERTE DIPLUMBANE
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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.
- Kleiner, Norbert,Draeger, Martin
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p. 323 - 342
(2007/10/02)
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