1633-09-6Relevant articles and documents
Synthesis and Properties of Ethyl, Propyl, and Butyl Hexa-alkyldisilanes and Tetrakis(tri-alkylsilyl)silanes
Ahmed, Mohammed A. K.,Wragg, David S.,Nilsen, Ola,Fjellv?g, Helmer
, p. 2956 - 2961 (2014)
The preparation of (R 3Si)4Si (R = ethyl, n-propyl, iso-propyl, n-butyl, and iso-butyl) was attempted using the procedure reported for [(CH3)3Si)]4Si.1 The type of alkyl group affected the resulting materials significantly. For R = ethyl, [(C2H5)3Si]2 [hexaethyldisilane (1)] was obtained phase pure if careful fractional distillation (under vacuum) was used, otherwise a mixture of 1, [(C2H5)2Si]4 (octaethyltetra-cyclo-silane), and other unidentified product(s) was obtained. For R = n-propyl a mixture of [(CH3CH2CH)3Si]2 (hexa-n-propyldisilane), [(CH3CH2CH2)2Si]4, (octa-n-propyltetra-cyclo-silane), [(CH3CH2CH2)3Si]4Si {tetrakis(tri-n-propylsilyl)silane} (2)], and other unidentified product(s) was obtained. From this mixture only 2, a new and previously unreported compound, was purified. 2 is the second compound of this type to be reported and is characterized by mass spectrometry (MS), elemental analysis (EA), and thermogravimetry (TG). The crystal structure of 2 is also reported [space group R βar{3}$ (no.148), a = 17.9249(10) ?, c = 12.2752(7) ?, at 100 K]. For R = iso-propyl pure [{(CH3)2CH2}3Si]2 [hexa-iso-propyldisilane (3)] was obtained in a good yield. For R = n-butyl or iso-butyl no phase pure compounds were synthesized. The pure compounds prepared have potential as precursors for the currently problematic atomic layer deposition of silicon, as demonstrated by their complete sublimation under thermal analysis. The sublimation temperature is dependent on the size of the molecule.
Cp2TiPh2-Catalyzed Dehydrogenative Coupling of Polyhydromonosilanes
Nakano, Taichi,Nakamura, Hidehisa,Nagai, Yoichiro
, p. 83 - 86 (1989)
The Cp2TiPh2-catalyzed reaction of dihydrosilanes afforded dehydrogenative coupling products, disilanes and/or trisilanes.The reaction using phenylsilane produced hydride-terminated poly(phenylsilylene) polymers with Mn=730 and Mw=960, which exhibited the longest UV absorption maximum at 245 nm (ε, 5.7x104).
Redox reactions of GeII and SnII dihalides with triethylsilane and triethylgermane
Nosov,Koroteev,Egorov
, p. 1325 - 1328 (2002)
Dihalogermylenes, dihalostannylenes, and their complexes (EI2, ECl2?dioxane, and (CO)5W=ECl2?THF, where E = Ge or Sn), unlike organylgermylenes, are not inserted at the Si-H (Ge-H) bond of triethylsilane (triethylgermane). The reactions of SnI 2, ECl2?dioxane, and (CO)5W=ECl 2?THF (E = Ge or Sn) with Et3E′H (E′ = Si or Ge) occur as redox processes. Depending on the nature of the reagents, the reactions afford products of oxidative coupling (Et3SiSiEt 3) and/or haloiodination (Et3SiX and Et3GeX) of triethylsilane (triethylgermane). The proposed mechanism of these reactions involves the electron transfer to form radical-ion pairs.
An Electroreductive Approach to Radical Silylation via the Activation of Strong Si-Cl Bond
Lu, Lingxiang,Siu, Juno C.,Lai, Yihuan,Lin, Song
supporting information, p. 21272 - 21278 (2020/12/21)
The construction of C(sp3)-Si bonds is important in synthetic, medicinal, and materials chemistry. In this context, reactions mediated by silyl radicals have become increasingly attractive but methods for accessing these intermediates remain limited. We present a new strategy for silyl radical generation via electroreduction of readily available chlorosilanes. At highly biased potentials, electrochemistry grants access to silyl radicals through energetically uphill reductive cleavage of strong Si-Cl bonds. This strategy proved to be general in various alkene silylation reactions including disilylation, hydrosilylation, and allylic silylation under simple and transition-metal-free conditions.
Nucleophilic displacement versus electron transfer in the reactions of alkyl chlorosilanes with electrogenerated aromatic anion radicals
Soualmi, Saida,Dieng, Mamadou,Ourari, Ali,Gningue-Sall, Diariatou,Jouikov, Viatcheslav
, p. 457 - 469 (2015/03/04)
Anion radicals of a series of aromatic compounds (C6H5CN, C6H5COOEt, anthracene, 9,10-dimethyl-, 9,10-diphenyl-and 9-phenylanthracene, pyrene and naphthalene) react with trialkyl chlorosilanes R1R2R3SiCl (R1-3 = Me, Et; R1,2 = Me, R3 = t-Bu) in multiple ways, following classical bimolecular schemes. The ratio of one-electron transfer (ET) to a two-electron process (SN2-like nucleophilic attack of the reduced form of mediator on the chlorosilane, with k2 ? 102-108 M-1 s-1) is inversely related to the steric availability of Si for nucleophilic displacement reactions. The nucleophilic substitution pathway mainly results in mono-and disilylated aromatic products. Paralleling the electrochemical data with DFT calculations, the role of silicophilic solvent (DMF) in SN process was shown to be quite complex because of its involvement into coordination extension at silicon, dynamically modifying energetics of the process along the reaction coordinate. Although 2,2'-bipyridine also forms delocalized persistent anion radicals, they do not induce neither ET nor SN reactions in the same manner as aromatic mediators. Silicophilicity of 2,2'-bipyridine being superior to that of DMF, a R3SiCl·bipy complex of hypercoordinated silicon with electroactive ligand was formed instead, whose reduction requires about 1 V less negative potentials than bipyridine itself.
