Blei(II)‐Verbindungen mit π‐gebundenen Pentamethylcyclopentadienylliganden – Synthesen, Strukturen und Bindungsverhältnisse

Abstract

Chem. Ber. 122 (1989) [865][866][867][868][869][870] Die in Tab

Synthesis and Characterization of a Quasi‐One‐Coordinate Lead Cation

“…[11,15,18,20,21,23] For the heaviest Group 14 elements, tin and lead, work had been focused primarily on derivatized cyclopentadienyl half-sandwich complexes, where the metal cation is h 5 bonded to five carbon atoms of the cyclopentadienyl ring. [1][2][3]17] Parallel, recent work has shown that bulky terphenyl ligands can stablize a range of lowcoordinate neutral and anionic species with unusual or previously unknown bonding. [27] We were therefore anxious to test the effectiveness of these useful monodentate ligands in stabilizing cationic Group 14 species with unusually low coordination numbers.…”

“…X-ray quality crystals of 2 were isolated after recrystallization from hexane. [30] The structure of 2 ( Figure 3 , [1] which range from 2.512 to 2.598 . The PbÀ centroid length for [(h 5 -C 5 Me 5 )Pb] + was found to be near 2.27 .…”

Synthesis and Characterization of a Quasi‐One‐Coordinate Lead Cation

“…There has been intense, recent interest in the synthesis and properties of heavier Group‐14‐element (Si–Pb) analogues of carbocations 1–26. However, they have proven difficult to isolate in the absence of stabilization by further coordination of the Group 14 element.…”

Electron impact and chemical ionisation mass spectrometry in the characterisation of organometallic silicon, germanium, tin and lead compounds

“…To date, no one cyclopentadienyl ligand has been structurally characterised as a half‐sandwich derivative for all three heavy group 14 elements, Ge, Sn and Pb. Furthermore, no isostructural derivatives have been characterised: in [E(η‐Cp*)(BF 4 )], for example, where E = Sn,22 a monomeric structure is observed but where E = Pb,29 a dimer, where the two BF 4 units bridge the two Pb centres and the Cp* ligands are terminal, is observed. For the Cp s ligand, where E = Ge, Sn or Pb, an isostructural series of tetramers is observed 4.…”