29955-12-2Relevant academic research and scientific papers
UNSATURATED SILICON COMPOUNDS. VII. PREPARATION AND STRUCTURE OF A SILAETHENE TETRAHYDROFURANATE
Wiberg, Nils,Wagner, Gerhard,Mueller, Gerhard,Riede, Juergen
, p. 381 - 392 (1984)
The compound tBu2SiF-CLi(SiMe3)2*4THF, accessible by a multistep synthesis, decomposes in diethyl ether at room temperature to give initially Me2SiF-CLi(SiMe3)(SiMetBu2)*nTHF, and finally a colourless crystalline tetrahydrofuran adduct of the silaethene Me2Si=C(SiMe3)(SiMetBu2).The adduct may be sublimed (with partial decomposition, the gas phase containing both discrete silaethene and THF).The crystals are orthorhombic, space group P212121 with lattice constants a 10.000(5), b 15.386(8), c 15.509(8) Angstroem, V 2386.23 Angstroem3 and dcalcd 1.038 g/cm3 for Z = 4 (T = -45 deg C).Full-matrix least-squares refinements of 208 parameters based on 1991 observed reflections (Fo 4.0 ?(Fo)) converged at R = 0.052.The THF molecule is clearly coordinated to the Si atom, which thereby adopts a distorted tetrahedral geometry.The trigonal planar sp2 geometry expected for both the Si and C atoms ofthe silaethene molecule is retained only for the latter.However, the bond distance between these atoms (1.747(5) Angstroem) is the shortest Si-C bond ever observed.The dative Si-O bond from the THF molecule, with a length of 1.878(4) Angstroem, is significantly longer than ordinary SiO bonds involving two- or three-coordinated oxygen.The implications of the structural parameters for the description of the bonding are discussed, and it is concluded that the adduct may be regarded as a zwitterion the formal charges of which are being located at the oxygen and the sp2 carbon atoms, respectively.Strong support for this concept is provided by a comparison with relevant structural data for silaethenes and phosphorus ylids.
Synthesis and deprotonation of (phenylselenolatodimethylsilyl) bis(trimethylsilyl) methane: The crystal structure of (Me3Si) 2(Me2SiBr)CH
Gupta, Sushil K.,Yumnam, Sujata,Hitchcock, Peter B.
scheme or table, p. 137 - 144 (2012/07/13)
The moisture-sensitive compound [{bromodimethylsilyl}bis(trimethylsilyl) methane], [(Me3Si)2(Me2SiBr)CH] 1 has been synthesized by the bromination of the hydride [(Me3Si) 2(Me2SiH)CH] in CC
On the Way to a Stable Silaethene Si=C : Sterically Overloaded Trisilylmethanes tBu2SiX-CY(SiMe3)2 (X, Y = H, Hal, Li)
Wiberg, Nils,Wagner, Gerhard
, p. 1455 - 1466 (2007/10/02)
Sterically overloaded trisilylmethanes tBu2SiX-CY(SiMe3)2 (X = H, Me, F, Br; Y = H, Br, Li) (3-12) are accessible via tBu2SiH-CH(SiMe3)2 (7) (from tBu2SiHF and LiCH-(SiMe3)2).The compounds are characterized by hindered rotation about the Si-C single bond shown.On gentle heating, tBu2SiF-CLi(SiMe3)2 (10) rearranges into the compound Me2SiF-CLi(SiMe3)(SiMetBu2) (14), which in turn decomposes at 100 deg C into LiF and the silaethene Me2Si=C(SiMe3)(SiMetBu2) (16).The latter, in the absence of a reactant, furnishes a mixture of secondary products and, in the presence of 1,3-butadiene, reacts to yield the Diels-Alder adduct 19.
