Hydrides of Silicon, Germanium, and Tin

Stannic bromide has been used as a selective brominating agent for silanes. Monosilane, disilane, and the methylsilanes Me3SiH4- (n = 1—3) all react to convert one Si—H bond into a Si—Br bond with no trace of 

Na+NHs-Na[SnH3] + MeCl-MeSnH3 + NaNH2-Na[MeSnH2] + MeCl  

Silicon(rv) Oxide and Related Silicates.—In this section, silicon dioxide and the silicates will be described separately emphasis will be laid on the inorganic chemistry of these compounds, and papers describing solely their catalytic, adsorption, diffusion, and other similar properties will not be discussed. The chemistry of the aluminosilicates and zeolites will not be discussed here recent publications in which their chemistry is described are considered in detail in 

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Lanthanide alkyl and aryl complexes react with organoelement hydride compounds, such as hydrides of silicon, germanium, and tin, and so on, resulting in a hydride transfer to the lanthanide metal atom. Among the organoelement hydrides, organosilanes are the most popular source of the hydride. 

The review is divided into sections according to the type of metal hydride for convenience in discussing the information systematically. At one extreme, kinetic studies have been performed with many types of silicon hydrides, and much of the data can be interpreted in terms of the electronic properties of the silanes imparted by substituents. At the other extreme, kinetic studies of tin hydrides are limited to a few stannanes, but the rate constants of reactions of a wide range of radical types with the archetypal tin hydride, tributylstannane, are available. Kinetic isotope effects for the various hydrides are collected in a short section, and this is followed by a section that compares the kinetics of reactions of silicon, germanium, and tin hydrides. 

One of the propagation steps in Scheme 1 is the hydrogen abstraction from the reducing agent by a radical. In a recent review Chatgilialoglu and Newcomb reported on the reaction kinetics of silicon, germanium and tin hydrides with radicals [12]. 

Limited studies of the germanium and tin hydride analogs of the silicon hydrides show that they share this ability to function as hydride sources in ionic hydrogenations however, their relatively greater reactivity toward acids appears to restrict their practical applications in organic synthesis.24,25... 

This review focuses on the kinetics of reactions of the silicon, germanium, and tin hydrides with radicals. In the past two decades, progress in determining the absolute kinetics of radical reactions in general has been rapid. The quantitation of kinetics of radical reactions involving the Group 14 metal hydrides in condensed phase has been particularly noteworthy, progressing from a few absolute rate constants available before 1980 to a considerable body of data we summarize here. 

Silane, germane, and stannane can be synthesized by the reduction of a variety of silicon, germanium, or tin compounds with active metal hydrides. The general method described below, involving the lithium hydroaluminate (LiAlHi) reduction of silicon tetrachloride and tin (IV) chloride, is convenient for the eflficient preparation of 1-50 mmoles of silane and stannane. The method is easily adapted to the synthesis of the deuterio compounds, i.e., silane-d4, germane-dt, and stannane-d4, by... 

Reactions of diphenylmethylene, generated by photodecomposition of diphenyldiazoraethane, with dimethyl thiophos-phite and with silicon, germanium and tin hydrides have been reported, and matrix isolation of diphenyloxiranone has been... 

Lukevics, E. and Voronkov, M. G., Addition Products from Organic and Inorganic Hydrides of Silicon, Germanium, Tin and Lead, Izd. Akad. Nauk Latv. SSSR, Riga, 1904.. 

Of all the reactions studied, only the synthesis of nitrogen oxides and acetylene in arcs or plasma torches and that of ozone in glow and corona discharges are of major importance. In addition, a few small-scale preparations of inorganic compounds have been developed, e.g. synthesis of hydrazine and of hydrides and halides of silicon, germanium, tin, lead, phosphorus or arsenic 3> ... 

Lithium aluminum hydride reacts with metal halides of silicon, germanium, tin, arsenic, and antimony to form hydrides, which are flammable and toxic ... 

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