47956-45-6Relevant academic research and scientific papers
Synthesis of 1,1-bis(silyl)-1-alkene derivatives bearing Si-H functional groups via Peterson protocol
Safa, Kazem D.,Hassanpour, Akbar,Tofangdarzadeh, Shahin
experimental part, p. 3622 - 3626 (2009/03/11)
Various aromatic aldehydes were converted to one-carbon elongate 1,1-bis(silyl)-1-alkene derivatives bearing Si-H functional and reactive groups in a convenient one-pot operation via the Peterson protocol. Then poly(styrene) and poly(α-methylstyrene) (I{cyrillic, ukrainian}&II) random homopolymers were synthesized by solution free radical polymerization at 70(±1) °C using α,α′-azobis(isobutyronitrile) (AIBN) as an initiator. The aldehyde group is introduced by direct electrophilic substitution of polymers I{cyrillic, ukrainian} and II. This formylation reaction was conducted in two different solvents: dichloromethane (CH2Cl2) and nitrobenzene (PhNO2). The results indicate that PhNO2 appeared to be a more suitable solvent for such an aldehyde functionalization of the polymers. The formylated polymers (ICHO, IICHO) were then converted to Si-H functionalized polymers (ISi-H, IISi-H) via reaction with tris(dimethylsilyl)methyllithium, (HMe2Si)3CLi.
Dimethoxydimethylsilane from silicon atoms and dimethyl ether: A combined matrix-spectroscopic and density functional theory study
Maier, Guenther,Glatthaar, Joerg
, p. 3350 - 3363 (2007/10/03)
The reaction between silicon atoms and dimethyl ether (6) has been studied in an argon matrix at 10 K and in solid dimethyl ether (6) at temperatures up to 80 K. In the initial step, a triplet n-adduct T-5 is formed between a silicon atom and 6. The next step needs photochemical activation. Depending on the relative dimethyl ether/argon ratio, the photoproduct is either dimethylsilanone (1) or singlet methoxymethylsilylene (S-2), which, in the presence of an excess of 6, exists as a dimethyl ether complex 8 of silylene S-2. Longer irradiation transforms dimethyl ether addition compounds S-8-t/ S-8-c into dimethoxydimethylsilane (7). If irradiation is applied directly during cocondensation of silicon atoms with 6, the only detectable products are 8 and 7. Upon further irradiation of the pure dimethyl ether matrix, the rest of 8 is also photoisomerized, and dimethoxydimethylsilane (7) is observed exclusively. The structural elucidation of all new species is based on comparison of the experimental observations with density functional theory calculations. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Base Cleavage of the Benzyl-Silicon Bonds in m-ClC6H4CH2SiMe(OH)2 and m-ClC6H4CH2Si(OH)3. Proposed Formation of Metasilicate Intermediates
Chmielecka, Jadwiga,Chojnowski, Julian,Stanczyk, Wlogdzimierz A.,Eaborn, Colin
, p. 865 - 872 (2007/10/02)
A kinetic study of the base-catalysed cleavage of the diol RSiMe(OH)2 (R = m-ClC6H4CH2) in Me2SO-H2O or MeOH-H2O has indicated that at high base concentrations the main process is the unimolecular dissociation of the dianion RSiMe(O-)2 into R- and Me(O-)Si=O (an analogue of acetate ion), both of which then react rapidly with the solvent.Likewise for the triol RSi(OH)3 in Me2SO-H2O the main process appears to be the formation of R- and the metasilicate ion HO(O-)Si=O from the dianion R(OH)Si(O-)2.Base cleavage of the silanols RSiMe2OH (R = PhCH2 or m-ClC6H4CH2) in Me2SO-H2O probably involves a contribution from the unimolecular dissociation of the anion RSiMe2O- to give R- and Me2Si=O.
Matrix IR spectroscopic study of the vacuum pyrolysis of octamethylcyclotetrasiloxane, allyloxy- and allyl(allyloxy)dimethylsilanes as well as 2,2,6-trimethyl-2-silapyrane as potential sources of dimethylsilanone
Khabashesku, V. N.,Kerzina, Z. A.,Maltsev, A. K.,Nefedov, O. M.
, p. 301 - 312 (2007/10/02)
The mechanism of vacuum pyrolysis of octamethylcyclotetrasiloxane, allyloxy- and allyl(allyloxy)-dimethylsilanes, and 2,2,6-trimethyl-2-silapyrane, potential sources of transient dimethylsilanone, has been studied by matrix isolation IR spectroscopy.Only in the case of allyloxydimethylsilane is there direct evidence of silanone (CH3)2Si=O formation, by observation of its most intense band at 798 cm-1 in the matrix IR spectrum of pyrolysis products.In all other cases the intermediate, (CH3)2Si=O, was found to be thermally unstable, undergoing fragmentation into SiO molecules and CH3 radicals, thus indicating silanone participation in the reactions studied.
Direct spectroscopic study of unstable molecules with silicon-oxygen multiple bonds: Low temperature matrix stabilization of (CH3)2Si=O and (CD3)2Si=O in the gas phase
Khabashesku, V. N.,Kerzina, Z. A.,Baskir, E. G.,Maltsev, A. K.,Nefedov, O. M.
, p. 277 - 294 (2007/10/02)
To continue the IR spectroscopic investigations of intermediates with doublebonded silicon, the silanones (CH3)2Si=O and (CD3)2Si=O have been generated by vacuum pyrolysis of the corresponding 6-oxa-3-silabicyclohexanes and of Diels-Alder adducts of silapyranes with maleic anhydride.The above silanones have first been stabilized from the gas phase in argon matrices at 12 K and studied by IR spectroscopy.Using the dependence of the spectra on temperature and pressure in the pyrolysis zone or in warming-up experiments (to 35-40 K) the following vibrational bands of silanones have been revealed: (CH3)2Si=O 1244, 1240, 1210, 822, 798, 770, 657 cm-1; (CD3)2Si=O 1215, 1032, 1007, 995, 712, 685, 674 cm-1.The limits of thermal ( 850 deg C) and kinetic (5 x 10E-4 torr) stability of dimethylsilanone were determined.By comparison of frequencies found with computed values the band 1210 cm-1 in (CH3)2Si=O (1215 cm-1 in (CD3)2Si=O) was assigned to a Si=O streching vibration.This frequency as well as the calculated force constant (8.32 mdyn/Angstroem) and order (1.45) of the Si=O bond are considered as evidence of significant double bonding in dimethylsilanone.
Reaction of 6-Oxa-3-silabicyclohexanes with Phosphinimines. Synthesis of 6-Vinyl-1,3-dioxa-2,4-disilacyclohexanes
Baceiredo, Antoine,Juengst, Clifford D.,Manuel, Georges,Weber, William P.
, p. 237 - 240 (2007/10/02)
Reaction of 3,3-dimethyl-6-oxa-3-silabicyclohexane with N-benzyltriphenylphosphinimine yields 1,3-butadiene and 2,2,4,4-tetramethyl-6-vinyl-1,3-dioxa-2,4-disilacyclohexane (3).A mechanism for the formation of (3) which involves the reaction of dimethylsilanone with 2,2-dimethyl-4-vinylsilaoxetane is proposed.
