2870-92-0Relevant articles and documents
Preparation, structural characterization, and photochemical reactions of silyl- and germylborates
Nanjo, Masato,Matsudo, Kazuhiko,Kurihara, Mari,Nakamura, Sayaka,Sakaguchi, Yoshio,Hayashi, Hisaharu,Mochida, Kunio
, p. 832 - 838 (2008/10/09)
Silylborates (Li[PhnMe3-nSiBPh3], n = 1-3) and germylborates (Li[PhnMe3-nGeBPh3], n = 1-3; M[Et3- GeBPh3], M = Li, Na, K) were prepared by the reaction of the corresponding silyl- and germylalkali metals with triphenylborane in a hexane/benzene mixed solvent. The silyl- and germylborates were fully identified by 1H, 13C, 11B, and 7Li NMR spectroscopic methods. The solid-state structure of germylborates Li[Ph3GeBPh3] and M[Et3GeBPh 3] (M = Li and Na) were determined by X-ray diffraction analyses. The polymeric structure of M[Et3GeBPh3] was observed in the solid state and in hydrocarbon solution. The alkali metal atoms were located near the center of the benzene ring of triphenylborane and interacted with the neighboring borate molecules by Li+-π interaction. The polymeric structure was broken by the addition of MeOH. However, M[Et 3GeBPh3] was coordinated by three MeOH molecules to form a dimeric structure without methanolysis reaction. The primary processes in photochemical reactions of silyl- and germylborates were investigated by chemical trapping experiments and the CIDEP (chemical-induced dynamic electron polarization) method. The cleavage of the Ge-B (or Si-B) bonds of germylborates (or silylborates) was considered most probably to occur from their triplet states.
New (diarylgermyl)lithiums
Castel,Riviere,Satge,Ko
, p. 205 - 210 (2008/10/08)
The new (diarylgermyl)lithiums R2GeHLi (2; R = phenyl, mesityl) were prepared in good yields by hydrogermolysis reactions of tert-butyllithium in THF. The stability of compounds 2 depends on the nature of the R group and the solvent. For R = Ph, in the presence of an amine (Et3N or Et2NMe), the same reaction leads to the formation of the polygermanes H(GePh2)nH (n = 2-4). The characterization of compounds 2 by IR and 1H and 13C NMR spectroscopy and their complexation with a crown ether are also reported. They are characterized by deuterolysis and alkylation reaction (with MeI and Me2SO4). Their germylation reactions with Ge-Cl reagents constitute a convenient way for synthesizing organo-hydropolygermanes. Compounds 2 also react with acyl chlorides to give new germyl ketones, R2HGeCOR′, and the unexpectedly stable β-germyl diketone Ph2Ge(COMes)2.
ELECTROCHEMICAL REDUCTION OF TRIORGANOHALO-SILANES AND -GERMANES
Corriu, R. J. P.,Dabosi, G.,Martineau, M.
, p. 63 - 72 (2007/10/02)
The electrochemical reduction of triorganohalo-silanes and -germanes in 1,2-dimethoxyethane has been investigated by polarography, cyclic voltammetry, controlled potential coulometry, and macroscale electrolysis.The reduction of the silicon compounds exhibits a single irreversible wave.The polarograms for the germanium compounds exhibit two irreversible waves.The second wave shifts to more anodic potentials with addition of phenol or acetic acid.Dimer (i.e. disilanes or digermanes) are the main product of macroscale electrolysis in aprotic solvent but the hydrides are the principal products in protic solution.The results are interpreted in terms of the coexistence of two separate processes.The first involves a one electron reduction followed by dimerization of the radical.At higher cathodic potential a two electron charge transfer step occurs to form an anion, which in aprotic solvents reacts with the starting halogeno compound to form dimer, and in protic solutions gives the hydride.
