18076-99-8Relevant articles and documents
Vinyl dichlorosilane and vinyl dibromosilane (H2C=CH-SiHX2, X = Cl, Br): Conformational structure and vibrational properties determined by gas-phase electron diffraction, ab initio molecular orbital calculations, and variable-temperature Raman spectroscopy
Johansen,Hagen,Hassler,Richardson,P?tzold,Stolevik
, p. 257 - 279 (2000)
The molecular structures, conformations, vibrational spectra, and torsional potentials of vinyl dichlorosilane (VDC) H2C=CH-SiHCl2, and vinyl dibromosilane (VDB) H2C=CH-SiHBr2, have been studied using gas-phase electron diffraction (GED) data at 23-25°C and variable-temperature Raman spectroscopy, together with ab initio molecular orbital calculations. The GED data were handled by a dynamic theoretical model using a cosine Fourier potential function in describing the torsional coordinate. According to the GED refinements, these molecules exist in the gas phase at room temperature as a mixture of two minimum energy conformers, syn (torsional angle φ(CCSiH) = 0°) and gauche (torsional angle φ(CCSiH) ? 120°). Relevant structural parameters for syn-VDC are as follows: Bond lengths (r(g)): r(Si-C) = 1.847(5) A?, r(Si-Cl) = 2.042(2) A?, r(C=C) = 1.357(7) A?. Bond angles (angle(α)): angle CSiCl = 110.3(6)°, angle CCSi = 121.8°(calc.). Relevant structural parameters for syn-VDB are as follows: bond lengths (r(g)): r(Si-C)= 1.827(9) A?, r(Si-Br) = 2.206(2) A?, r(C=C) = 1.366(10) A?. Bond angles (angle α): angle CSiBr = 110.1(8)°, angle CCSi=121.7°(calc.). Uncertainties are given as 2σ (σ includes estimates of uncertainties in voltage/height measurements and correlation in the experimental data). From the variable-temperature Raman investigation in the liquid phase, the energy differences are: VDC, ΔE°(S-G) = + 0.11 ± 0.06 kcal mol-1; VDB, ΔE°(S-G) = + 0.23 ± 0.07 kcal mol-1. The Raman energies are average values obtained from two separate line doublets for each molecule, and they have been used in the GED least-squares refinements as valuable constraints. (C) 2000 Elsevier Science B.V.
Silaethane XIII. Erzeugung von SiC-Doppelbindungen in der Koordinationssphaere von Eisencarbonylkomplexen
Auner, Norbert,Grobe, Joseph,Schaefer, Thomas,Krebs, Bernt,Dartmann, Mechtild
, p. 7 - 24 (1989)
The suitability of the vinylsilyliron complexes RSi(Cl)CH=CH2 t (3), Fe(CO)2cp (4)> and of MeSi(Cl)CMe=CH2 (14) as precursors for the generation of silaethane derivatives has been investigated.The starting compounds 1 to 4 and 14 can be obtained from Me(Vi)SiCl2, Ph(Vi)SiCl2, HSiCl3 and MeSiCl3, respectively, by judicious combination of published procedures.They have been characterized by analytical and spectroscopic studies as well as by comparison with known data.The generation of the Si=C intermediates was attempted by treating the vinylsilyl iron complexes with LiBut at low temperatures (-10 deg C).Only with 1 was a smooth reaction observed with formation of the Z/Z dimer 1,3-bis(cyclopentadienyl-dicarbonyliron)-1,3-dimethyl-2,4-dineopentyl-1,3-disilacyclobutane (16) of the expected silaethane MeSi=CHCH2But.This intermediate also seems plausible on the basis of trapping experiments, using 2,3-dimethyl-1,3-butadiene, isoprene or 1,3-cyclohexadiene.However, since 16 is formed as the main product even in the presence of an excess of these dienes, the cyclization of the lithiated precursor ClSiMeCH(CH2But)SiMeCH(Li)CH2But must be regarded as an alternative route to 16.The crystal and molecular structure of 16 indicate a Z/Z configuration of the bulky ring substituents.The disilacyclobutane skeleton is nonplanar with a dihedral angle of 18.7 deg.Similar to other 1,3-disilacyclobutane derivatives, 16 shows a fairly short transannular Si(1)...Si(2) distance of 2.641(1) Angstroem.Due to the -I effect of the phenyl substituent reaction of 2 with LiBut yields oligomeric coupling products, whereas in 3, 4 or 14 for steric reasons LiBut clearly attacks the carbonyl ligand instead of the CC double bond to give black, pyrophoric solids of low solubility.
Direct synthesis of organodichlorosilanes by the reaction of metallic silicon, hydrogen chloride and alkene/alkyne and by the reaction of metallic silicon and alkyl chloride
Okamoto, Masaki,Onodera, Satoshi,Yamamoto, Yuji,Suzuki, Eiichi,Ono, Yoshio
, p. 71 - 78 (2007/10/03)
Dichloroethylsilane was synthesized by the reaction of metallic silicon, hydrogen chloride and ethylene using copper(I) chloride as the catalyst, the silicon conversion and the selectivity for dichloroethylsilane being 36 and 47%, respectively. At a lower reaction temperature or at a higher ratio of ethylene: hydrogen chloride a higher selectivity was obtained, however the silicon conversion was lower. The silicon-carbon bond formation is caused by the reaction of a surface silylene intermediate with ethylene. The reaction with propylene in place of ethylene gave dichloroisopropylsilane (22% selectivity) and dichloro-n-propyl-silane (8% selectivity) together with chlorosilanes. A part of the dichloroisopropylsilane is formed by the reaction of silicon, hydrogen chloride and isopropyl chloride formed by hydrochlorination of propylene. Use of acetylene instead of alkenes resulted in dichlorovinylsilane formation with a 34% selectivity. Alkyldichlorosilanes were also produced directly from silicon with alkyl chlorides, propyl and butyl chlorides. During the reaction the alkyl chloride is dehydrochlorinated over the surface of copper originating from the catalyst to afford hydrogen chloride and alkene. The hydrogen chloride formed participates in the formation of the silicon-hydrogen bond in alkyldichlorosilane, and the reaction of silicon, hydrogen chloride and alkene also causes alkyldichlorosilane formation. The reaction with isopropyl chloride gave a very high selectivity (85%) for dichloroisopropylsilane, the silicon conversion being 86%. The Royal Society of Chemistry 2001.
