17877-23-5Relevant articles and documents
Novel Si(II)+and Ge(II)+Compounds as Efficient Catalysts in Organosilicon Chemistry: Siloxane Coupling Reaction ?
Fritz-Langhals, Elke,Kneissl, Sotirios,Piroutek, Phillip,Werge, Sven
, (2020/09/02)
Novel catalytically active cationic Si(II) and Ge(II) compounds were synthesized and isolated in pure form. The Ge(II)+-based compounds proved to be stable against air and moisture and therefore can be handled very easily. All compounds efficiently catalyze the oxidative coupling of hydrosil(ox)anes with aldehydes and ketones as oxidation reagents and simultaneously the reductive ether coupling at very low amounts of 0.01 mol %. Because the catalysts also catalyze the reversible cyclotrimerization of aldehydes, paraldehyde can be used as a convenient source for acetaldehyde in siloxane coupling. It is shown that the reaction is especially suitable to make siloxane copolymers. Moreover, a new fluorine-free weakly coordinating boronate anion, B(SiCl3)4-, was successfully combined with the Si(II) and Ge(II) cations to give the stable catalytically active ion pairs Cp*Si:+B(SiCl3)4-, Cp*Ge:+B(SiCl3)4-, and [Cp(SiMe3)3Ge:+]B(SiCl3)4-.
An efficient catalytic approach for the synthesis of unsymmetrical siloxanes
Hreczycho, Grzegorz
, p. 67 - 72 (2015/01/30)
The potential for expanding the variety of catalytic methods for siloxane bond formation is explored. Alkoxysilanes react with methylallylsilanes in the presence of scandium(III) trifluoromethanesulfonate to yield disiloxanes and isobutene. The reaction p
Catalytic hydrogen evolution from hydrolytic oxidation of organosilanes with silver nitrate catalyst
Teo, Alan Kay Liang,Fan, Wai Yip
, p. 37645 - 37648 (2014/11/27)
In the light of uncertainty over the amount of recoverable fossil fuel reserves, hydrogen is touted to be a promising energy carrier in the future. Nevertheless, hydrogen storage remains a daunting challenge but a potential reaction for the generation of hydrogen on demand is the hydrolytic oxidation of organosilanes. Here, we demonstrate that silver nitrate, a readily available ionic salt, can catalyze the hydrolysis of organosilanes to produce hydrogen and organosilanols. In particular, turnover numbers and turnover frequencies in excess of 5 × 103 and 102 min-1 respectively are obtainable for the hydrolysis of triethylsilane at room temperature. This proposed silver nitrate mediated system is, by far, the simplest and cheapest catalytic hydrolysis of organosilanes. Results from the kinetic studies suggested a mechanistic scenario in which the hydrolysis of organosilanes is third order overall and first order in organosilane, water, and catalyst. The high hydrogen yield observed makes the silver nitrate catalyst an attractive material for hydrogen evolution. the Partner Organisations 2014.
