Gas-phase reactions of Si+ and SiOH+ with molecules containing hydroxyl groups: possible ion-molecule reaction pathways toward silicon monoxide, silanoic acid, and trihydroxy-, trimethoxy-, and triethoxysilane
| Autor: | Diethard K. Bohme, S. Wlodek, A. Fox |
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| Rok vydání: | 1987 |
| Předmět: | |
| Zdroj: | Journal of the American Chemical Society. 109:6663-6667 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja00256a018 |
| Popis: | Reactions of ground-state Si+ (2P) and SiOH' ions have been investigated with H2, D2, CO, H20, CH,OH, C2H50H, HCOOH, and CH,COOH at 296 2 K with the selected-ion flow tube (SIFT) technique. Both ions were found to be unreactive toward H2, D2, and CO. Ground-state silicon ions were observed to react with the hydroxyl-containing molecules to produce the silene cation SiOH+, which may neutralize by proton transfer or by recombination with electrons to form silicon monoxide. SiH302+, which may neutralize to produce silanoic acid, was observed to be the predominant product in the reactions of SOH+ with H20, C2H50H, and HCOOH, while direct formation of silanoic acid is likely in the reaction observed between SOH+ and CH,COOH. A single mechanism involving 0-H insertion of the SOH+ silylene cation provides a plausible explanation for all of the results obtained with this ion. Also, further chemistry was observed to be initiated by SiH302+. Solvation was the predominant channel seen with water and ethanol while SiCH303+ and SiH503+ were the predominant products observed with formic acid. Several reaction sequences were identified in methanol, ethanol, and formic acid which are postulated to lead to the complete saturation of Si+ forming ions of the type HSi(OCH3)3H+, HSi(OC2H5)3H+, and HSi(OH)3H+ which may neutralize to generate trimethoxysilane, triethoxysilane and trihydroxysilane, respectively. |
| Databáze: | OpenAIRE |
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