Trichlorogermane

Additional preparative method passing HCl over powdered Ge (with heating) Ge + 3 HCl = GeHCla + Hg. 

Colorless, mobile liquid. Distills at 75°C. Loses HCl with the formation of GeClg at about -30°C. The HCl remains dissolved in the GeHClg. Therefore GeClg can be prepared from GeHClg at -30°C (under suction). Conversely, GeHCls can be obtained from GeCls by condensing HCl upon the latter. M.p. -71°C. 

The apparatus shown in Fig. 235 is connected to a vacuum pump. The thick-wall Pyrex ampoule a contains 10 g. of Gelg. After evacuation, 2.1 ml. (4.8 g.) of CH3I is allowed to distill from the graduated vessel b into the ampoule, which is cooled with acetone-Dry Ice mixture. The ampoule a is now sealed at the neck and heated for 24 hours at 110°C. (Caution danger of explosion, particularly at the beginning. If the ampoule is too weak.) 

If the initial charge of Gels is oxide-free, the crystals disappear as the reaction proceeds and a clear solution is obtained. 

Provided too great an excess of CH3I was not charged in, the yellow solution hardens on cooling. The excess CH3I is distilled off by cooling the side bulb c in a cooling mixture. The vessel is then opened the 

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The spirocyclic pentacoordinate germanium zwitterion 74 was prepared from 2,3-naphthalenediol in three steps starting with a trichlorogermane (Equation (132)).172 The bicyclic species 75 can be prepared in modest yield... 

Equation (133)) and subsequently can be converted into a pentacoordinate 1,2-oxagermetanide (Scheme 23).173 Reaction of trichlorogermanes with mercaptoacetic acid or 2-mercaptoethanol also yields pentacoordinate organo-germanium compounds (Equations (134)174 and (135)).175... 

Germanium also forms organometallic compounds. Over two hundred have been reported, from chloromethyl trichlorogermane. CICH-GeCF to cyclnleirakis (diphenyl germnnoxanel. [(CsHOiGeOJa. 

The redistribution and cleavage reaction of mixtures of tetramethylgermane and tetrabutylgermane with excess of aluminum chloride give di- as well as trichlorogermanes having mixed alkyl groups. 

In 1958, Nesmeyanov and coworkers290 found that decomposition of aryldiazonium tetrafluoroborates with zinc dust in the presence of GeCLt resulted in formation of aryl-trichlorogermanes in <30% yield, isolated as the corresponding arylgermsesquioxanes. 

The choice of the reducing agent is quite important. Thus, reduction of the precursor (2,6-diisopropylphenyl)trichlorogermane with Mg/MgBr2 in THF resulted in the formation of tetrakis(2,6-diisopropylphenyl)digermene23 instead of prismane 5. 

The aryl-substituted octagermacubane, octakis(2,6-diethylphenyl)pentacyclo[4.2.0.02 5. O3 8.04 71 octagennane 10, was synthesized by the dehalogenative coupling of (2,6-diethylphenyl)trichlorogermane with Mg/MgBr2 in THF in 1% yield as yellow crystals (Scheme 7)31. This compound was found to be less stable to atmospheric moisture and... 

The organotin method was also used for preparation of 1-hydrogermatrane 187 from the trichlorogermane complex with ether572. 

Trichlorogermane reactions involving participation of dichlorogermylene are not oxidation-reduction reactions in the usual sense of this term, though they are described by Gen/GeIV transfers. At the same time, the reductive properties of trichlorogermane can be illustrated by the reduction of nitrobenzenes to anilines. 

Finally, the reaction of double germylation, such as formation of Cl3GeCH2CH2GeCl3 from ethylene and the etherate of trichlorogermane, is of great importance. 

Experimental data of reactions of trichlorogermane are reviewed elsewhere7,11. The main aim of this chapter is to gather investigations of the mechanistic aspects of reactions of trichlorogermane and to apply these data for providing a rational explanation of the experimental facts. 

The extraordinarily big shift of the nuclear quadrupole resonance frequency in the etherate of trichlorogermane in comparison with trichlorogermane itself (9 MHz from 23 to 14 MHz) can also be explained by a change in the coordination of the central atom to the trigonal-pyramidal form20. 

III. ACIDIC AND SUPERACIDIC PROPERTIES OF TRICHLOROGERMANE A. Chemical Examples and Determinations... 

The exact determination of the acidic properties of trichlorogermane is experimentally difficult. First, it should be remembered that solvate-free trichlorogermane is a covalent compound. Only the presence of species such as an ether, amine or phosphine change the nature of trichlorogermane so that it easily ionizes. Hence, the acidic properties of H+[GenCl3] in the solvated form can only be estimated indirectly. 

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