Organogermanium compounds,

Considerable variation is found in the systems of naming organogermanium compounds discussed in the earlier literature. In order that these compounds may be named in compliance with modern standards of uniformity and clarity, the following recommendations are made  

Where organic nomenclature is ambiguous or inapplicable, the germanium compounds should be named in accordance with current recommendations for naming similar silicon compounds.2,3 

Inorganic nomenclature is recommended in accordance with present inorganic usage if such naming is simpler and more specific. 

This was the method used by Winkler to prepare the first known organogermanium compound, tetraethylgermane. It is not commonly used at present. 

Diphenylmercury combines with germanium(IY) chloride in a sealed tube at 140° to form phenyltrichlorogermane. Benzyltrichlorogermane, p-tolyltrichlorogermane, and (p-dimethylaminophenyl)trichlorogermane have been prepared in the same manner. No modifications of this method have come into common use. 

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Organogermanium Compounds. The field of organogermanium chemistry has drawn widespread interest for many years. 

E. Rijkens, Organogermanium Compounds, Germanium Research Committee, Utrecht, the Netherlands, 1960. 

The first examples of optically active organogermanium compounds [see Ref. 2)] in which the metal atom is again the only chiral center were published in 1963, by Eaborn 3 and by Brook4>. They prepared optically pure (+)-ethyl- and (-)-methyl- 1-naphthylphenylgermanium hydrides, using Sommer s resolution method u. 

Organogermanium compounds resemble their organosilicon analogues in their reactivity in crosscoupling reactions, and require nucleophilic activation (Section 9.6.3.2 2)... 

TABLE 1. Standard enthalpies of formation of organogermanium compounds (kJmol -i)a... 

TABLE 2. Bond dissociation enthalpies in organogermanium compounds (kJmol-1)... 

Organogermanium compounds can be mineralized by wet oxidative digestion for 4 h at 70°C, in aqueous potassium persulphate, at pH 12. After dilution to an adequate concentration germanium can be determined by ICP-AES (inductively coupled plasma atomic emission spectrometry)9. 

Organosilicon and organogermanium compounds were separated at 330-350 K on a Cromaton column coated with squalene. Improved quantitative determination was achieved by accumulation of preliminary decomposition products of the organometallic compounds in a graphite atomizer, followed by ETAAS32. 

See introductory remarks in Section I.A.4. Information on NMR spectra of organogermanium compounds appears in Table 2. Most sources usually include chemical shift values, S, and coupling constants, J, however, in many cases other features are also discussed. A general discussion of 73Ge NMR appeared in the literature57. 

See introductory remarks in Section I.A.4. Table 3 summarizes examples of crytallo-graphic analysis published in the recent literature, with brief comments about structural features of organogermanium compounds. 

TABLE 2. Structural determination of organogermanium compounds by NMR spectroscopy... 

Bulky substituents confer stability on organogermanium compounds. Scheme 1 shows possible derivatization reactions for some substitued germanes and digermanes. Compounds d and e are obtained from reactions a and b3 as mixtures of diasteroisomers, however, reactions a3, b4 and b3 are more stereospecific. Compounds b-i in the scheme were characterized by H NMR spectra118. 

Analytical aspects of organogermanium compounds bond with water and organic compounds, as shown in reactions 15—1853. 

The abbreviations used in this chapter appear after the list of contents of the chapter on organogermanium compounds, Chapter 7, page 339. 

Gmelin Handbook of Inorganic Chemistry, 8th ed., Organogermanium Compounds, Part 3, Springer, Berlin, 1990 pp. 342-348. 

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