Hydrides germanes

Metal hydrides Germane, lithium aluminum hydride, potassium hydride, sodium hydride... 

Lithium aluminum hydride Germanes from germanols... 

Germenes and germaphosphenes can be reduced with lithium aluminum hydride to give the corresponding germanes. This reaction apparently has not been examined for other unsaturated germanium derivatives. 

Preparative hazard See Bromine Germane See related METAL HYDRIDES... 

The first chiral nonracemic germanes were prepared from the tetraphenyl derivative through a series of successive electrophilic and nucleophilic substitutions as illustrated in Scheme 1. Brook and Peddle were able to separate the diastereomeric (—)-menthyloxy derivatives 1 and 2 by fractional crystallization1. Treatment of each diastereomer with LiAlFLt afforded the (+) and (—) enantiomeric hydrides R-3 and S-3, respectively,... 

In a second Walden cycle, germane S -3 was converted to the chloro derivative R-13, which was reduced by LiAlPLt to the enantiomeric germane R-32. The configuration of the chloride J -13 was assigned by mixture melting point with the known R sila analogue and from consideration of Brewster s rales. Thus, chlorination must proceed with retention and hydride reduction with inversion of configuration. 

Several triphenylgermanium hydrides have been prepared where the hydride atom is encapsulated by substituents on the phenyl ligands,95,108-111 as illustrated in Equations (84)-(86).110,111 The germanium atom of 42a-c are formally hexacoordinate and that of 43 is heptacoordinate. A tribenzobarellenegermane compound with a trihydro-germane moiety attached to the bridgehead carbon was prepared and characterized (Equation (87)), and this species was found to be exceptionally air stable.1... 

Tris(trimethylsilyl)silane [20,21], thiols [22], germanes [23-25] and gallium hydride [26] can be added easily to terminal alkynes in the presence of Et3B/02. This process was extended to internal alkenes (Scheme 8, Eq. 8a) as well as silyl enol ethers (Eq. 8b) by using tri-2-furylgermane. In this last case, basic or acidic treatment of the main syn /J-siloxygcrmanc furnishes the corresponding E- or Z-alkene, respectively [24],... 

Table I includes the relative bond dissociation enthalpies obtained for some group 14 hydrides by photoacoustic calorimetry,7 10 The data demonstrate that, for the trialkyl-substituted series, the bond strengths decrease by 6.5 and 16.5 kcal/mol on going from silane to germane and to stannane, respectively. The silicon-hydrogen bonds can be dramatically weakened by successive substitution of the Me3Si group at the Si-H functionality. A substantial decrease in the bond strength is also observed by replacing alkyl with methylthio groups.

Formation of magnesium and calcium hydride compounds was first recognized by German chemists yet at the end of nineteenth century [95] but it took more than a half a century before a substantial yield of Mg hydride was obtained from direct... 

This reaction probably proceeds via the neutral hydride that undergoes reductive elimination of germane. The stereochemistry observed (retention of configuration) is in agreement with a reductive elimination and with the assumption that the formation of the molybdenum-germanium bond proceeds with retention of configuration (cf. Sect. 3.1.2). 

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