3124-01-4Relevant articles and documents
Synthesis and crystal structures of the compounds [Sn{C(SiMe2Ph)3}Cl]2, [Pb{C(SiMe3)3}Cl]3, and [M{C(SiMe3)2(SiMe2OMe)}Cl]2 (M = Sn or Pb)
Eaborn, Colin,Hitchcock, Peter B.,Smith, J. David,S?zerli, Sebnem E.
, p. 5653 - 5658 (1997)
The title compounds have been made by treatment of SnCl2or PbCl2 in tetrahydrofuran with the appropriate reagent LiR, where R = (PhMe2Si)3C, (Me3Si)3C, or (MeOMe2Si)(Me3-Si)2C, and their crystal structures determined. In all four compounds, as in the previously reported [Pb{C(SiMe2Ph)3}Cl]2, the metal atoms are linked by bridging Cl atoms, unsymmetrically except in the case of the trimeric [Pb{C(SiMe3)3}Cl]3 (in which the six-membered ring has a distorted boat form). In [M{C(SiMe3)2(SiMe2OMe)}Cl]2, M = Sn or Pb, which are isomorphous, there are (relatively weak) intramolecular MeO?M interactions in addition. The compounds [Pb{C(SiMe2Ph)3}Cl]2 and [Pb{C(SiMe3)3}Cl]3 are the only known σ-bonded mono(organo)lead(II) compounds to have been structurally characterized, and [Sn{C(SiMe2-Ph)3}Cl]2 is only the second solvent-free mono(alkyl)tin(II) compound. All of the compounds are yellow and air-sensitive in the solid and in solution, and the lead compounds are readily decomposed in solution by exposure to daylight.
Synthesis and reactivity of [2]ferrocenophanes containing C-Pb and C-Zr bridges
Bartole-Scott, Alexandra,Lough, Alan J.,Manners, Ian
, p. 429 - 436 (2008/10/09)
The synthesis, characterization and reactivity of novel carbometalla[2]ferrocenophanes (η-C5Me4)Fe(η- C5H4)CH2ER2 (14) and (15) (E = Pb, R = Ph or E = Zr, R = (η-C5H5)) are reported. Compounds 14 and 15 were prepared by the reaction of the dilithiated species (η-C5Me4)Fe(η-C5H4Li)CH 2Li · xTMEDA with the appropriate dichlorodiorganoplumbane or dichlorozirconocene in low yields (ca. 20%). The Pb species 14 was characterized by 1H and 13C NMR, and MS, however it could not be cleanly separated from pentamethylferrocene. Moreover, it was found that the C-Pb bonds of 14 underwent facile cleavage, and under ambient light or at room temperature, 14 decomposed to Pb2Ph6 and pentamethylferrocene. Compound 15, on the other hand, was stable and readily purified; this species was characterized by 1H and 13C NMR, UV-Vis, MS, and elemental analysis. Single crystal X-ray diffraction studies of this compound revealed the presence of a moderate degree of ring-tilt with a value of α = -5.5(2)°(a negative value is used to denote tilting away from the bridging elements), and a potentially moderate degree of strain due to a large β(Zr) of 31.6(1)°(angle between Cp′(Fe) plane and ipso-Cp′-Zr bond). Attempted thermal ring-opening polymerization (ROP) of 15 resulted only in decomposition and attempted transition metal-catalyzed and photolytic ROP were also unsuccessful. The reaction of 15 with HCl · Et2O resulted in cleavage of the C-Zr bonds, and led to the formation of pentamethylferrocene.
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.
