5272-21-9Relevant academic research and scientific papers
Iridium-catalyzed hydrogen production from hydrosilanes and water
Garces, Karin,Fernandez-Alvarez, Francisco J.,Polo, Victor,Lalrempuia, Ralte,Perez-Torrente, Jesus J.,Oro, Luis A.
, p. 1691 - 1697 (2014/06/24)
The iridium(III) complex [Ir(H)(CF3SO3)(NSiN)(coe)] (NSiN=fac-coordinated bis(pyridine-2-yloxy)methylsilyl, coe=cyclooctene) has been proven to be an effective catalyst precursor for hydrogen production from the hydrolysis of hydrosilanes at room temperature. The reaction performance depends both on the nature of the silane and the solvent. Interestingly, high turnover frequencies of around 105 h-1 were obtained by using Et2SiH2 or (Me2HSi)2O as hydrogen sources and THF as the solvent. Moreover a mechanistic insight into this Ir-catalyzed hydrogen generation process, based on both theoretical calculations and NMR spectroscopy, is reported. The overall catalytic cycle can be viewed as a two-stage process that involves water-promoted Si-H bond activation followed by water splitting by a proton transfer. From hydrosilanes to hydrogen: The iridium(III) complex [Ir(H)(CF3SO 3)(NSiN)(coe)] is an effective homogeneous catalyst precursor for hydrogen production from the hydrolysis of hydrosilanes (NSiN=fac-coordinated bis(pyridine-2-yloxy)methylsilyl, coe=cyclooctene).
Preparation of branched siloxane
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Page/Page column 10-11, (2010/02/10)
By reacting a branched siloxane compound of formula (2) containing compounds of formula (1) as an impurity with a disiloxane compound of formula (3) in the presence of an acid compound, there is prepared a branched siloxane of formula (2) containing a reduced level of compounds of formula (1).R1?nSi(OSiR2?3)3-n(OR3)R1?nSi(OSiR2?3)4-nR2?3SiOSiR2?3 R1 is a monovalent hydrocarbon group, R2 and R3 are H or monovalent hydrocarbon groups, and n is 0 or 1.
The hydroxyl radical reaction rate constants and atmospheric reaction products of three siloxanes
Markgraf, Stewart J.,Wells
, p. 445 - 451 (2007/10/03)
The relative rate technique has been used to measure the hydroxyl radical (OH) reaction rate constant of hexamethyldisiloxane (MM, (CH3)3Si-O-Si(CH3)3), octamethyltrisiloxane (MDM, (CH3)3Si-O-Si(CH3)2-O-Si(CH 3)3), and decamethyltetrasiloxane (MD2M, (CH3)3Si-O-Si(CH3)2-O-Si(CH 3)2-O-Si(CH3)3). Hexamethyldisiloxane, octamethyltrisiloxane, and decamethyltetrasiloxane react with OH with bimolecular rate constants of 1.32 ± 0.05 × 10-12 cm3molecule-1s-1, 1.83 ± 0.09 × 10-12 cm3 molecule-1, and 2.66 ±0.13 × 10-12 cm3molecule-1s-1, respectively. Investigation of the OH + siloxane reaction products yielded trimethylsilanol, pentamethyldisiloxanol, heptamethyltetrasiloxanol, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and other compounds. Several of these products have not been reported before because these siloxanes and the proposed reaction mechanisms yielding these products are complicated. Some unusual cyclic siloxane products were observed and their formation pathways are discussed in light of current understanding of siloxane atmospheric chemistry.
MUTUAL EFFECT OF SOLUTIONS OF SALTS AND HCl ON COHYDROLYSIS OF METHYLCHLOROSILANES
Kopylov, V. M.,Agashkov, S. P.,Sunkovich, G. V.,Prikhod'ko, P. L.
, p. 692 - 697 (2007/10/02)
In hydrolytic polycondensation of Me2SiCl2, the combined effect of salts and HCl causes a decrease in the yield of 4, and this effect increases with an increase in the binding strength of the water with the salt in hydrate complexes and the concentration of HCl.The combined effect of salts and HCl on the composition of the products of the reaction in hydrolytic copolycondensation of Me2SiCl2 with Me3SiCl and MeSiCl3 with Me3SiCl increases with an increase in the degree of binding of water in hydrate complexes, caused by competition in the formation of hydrate complexes between the salt and HCl.
