Gas-phase chemistry of pentacoordinate silicon hydride ions
- Purdue Univ., West Lafayette, IN (United States)
The formation, thermochemical properties, and reactivity of gas-phase pentacoordinate silicon hydride anions are described. These ions are produced as the major products of reactions between H[sup [minus]] and alkylsilanes under flowing afterglow conditions at room temperature. Substituted silicon hydride ions are formed by addition of nucleophilic anions such as F[sup [minus]N], alkoxides, nitrile anions, and CF[sub 3][sup [minus]] to SiH[sub 4] and to primary, secondary, or tertiary alkylsilanes. The parent ion of the series, SiH[sub 5][sup [minus]], is formed by hydride transfer from alkyl silicon hydride ions to SiH[sub 4]. Pentacoordinate silicon hydride ions are shown to be reactive hydride reducing agents, transferring H[sup [minus]] to a wide variety of organic, inorganic, and transition-metal organometallic species. Silicon hydride ions undergo sequential hydride-deuteride exchange reactions with SiD[sub 4] by a mechanism analogous to protonic H/D exchange in gas-phase carbanions. Reactions with Bronsted acids lead to protolytic cleavage of an Si-H bond in the anion and formation of H[sub 2]. Depending upon the structure and acidity of the reactant acid, these reactions produce the corresponding silyl anion and both the free and silicon-complexed conjugate base anion. 61 refs.
- OSTI ID:
- 7080375
- Journal Information:
- Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 116:23; ISSN JACSAT; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ANIONS
BROENSTED ACIDS
CHARGED PARTICLES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COORDINATION VALENCES
FLUIDS
GASES
HYDRIDES
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IONS
KINETICS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
SILANES
SILICON COMPOUNDS
SYNTHESIS
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
VALENCE