541-02-6Relevant articles and documents
Tris(pentafluorophenyl)borane-Catalyzed Reactions of Siloxanes: A Combined Experimental and Computational Study
Mathew, Jomon,Eguchi, Katsuya,Nakajima, Yumiko,Sato, Kazuhiko,Shimada, Shigeru,Choe, Yoong-Kee
, p. 4922 - 4927 (2017)
The reaction of 1,1,3,3-tetramethyldisiloxane with 1-octene as a model reaction of silicone curing catalyzed by B(C6F5)3 resulted in the redistribution of the disiloxane into dimethylsilane and cyclic oligosiloxanes, and the subsequent hydrosilylation reaction of dimethylsilane afforded dimethyldioctylsilane. To obtain insights into the reaction mechanism and possibility alter the reaction pathway to favor the hydrosilylation over the redistribution, mechanistic analysis of the reaction between a hydrosiloxane (1,1,3,3-tetramethyldisiloxane, silox-H) and a vinylsiloxane (1,1,3,3-tetramethyl-1,3-divinyldisiloxane, silox-vin) in the presence of B(C6F5)3 was performed through density functional theory calculations. The results of the calculations indicate that the activation of a Si–H bond in silox-H by B(C6F5)3 initiates the reaction to form the B(C6F5)3–silox-H complex with a Lewis acidic silicon atom and a hydridic hydrogen atom. The B(C6F5)3–silox-H complex can undergo two different reaction pathways, that is, trisiloxane formation and the hydrosilylation of silox-vin by silox-H. The trisiloxane formation involves trisilyloxonium ions as intermediates and can lead to either the homotrisiloxane of silox-H or a mixed trisiloxane of silox-H and silox-vin. The energetics of the reaction pathways predict the preference of trisiloxane formation over hydrosilylation, and the fine tuning of the steric and electronic natures of the substrates could alter the thermodynamic and kinetic favorability.
Hydrogenolysis of Polysilanes Catalyzed by Low-Valent Nickel Complexes
Comas-Vives, Aleix,Eiler, Frederik,Grützmacher, Hansj?rg,Pribanic, Bruno,Trincado, Monica,Vogt, Matthias
supporting information, p. 15603 - 15609 (2020/04/29)
The dehydrogenation of organosilanes (RxSiH4?x) under the formation of Si?Si bonds is an intensively investigated process leading to oligo- or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si?Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo- and polysilanes that is highly selective and proceeds under mild conditions. New low-valent nickel hydride complexes are used as catalysts and secondary silanes, RR′SiH2, are obtained as products in high purity.
METHOD FOR PRODUCING SILOXANE OLIGOMER
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Paragraph 0034; 0045, (2017/07/23)
PROBLEM TO BE SOLVED: To provide a production method capable of simply producing a siloxane oligomer in a high yield when producing a siloxane oligomer by hydrolysis of a silicon halide compound and to provide a production method capable of selectively producing a linear or cyclic siloxane oligomer in particular. SOLUTION: The siloxane oligomer can be efficiently produced without performing any special agitation by providing two electrospray nozzles to oppose to each other in a medium liquid and in the medium liquid, electrostatically spraying in an electric field a first liquid sample containing a silicon halide compound from one nozzle and electrostatically spraying in an electric field a second liquid sample containing water from the other nozzle and allowing the liquid samples to collide and fuse with each other. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPO&INPIT
