Germanium organic derivatives

Studies relating to organic germanium compounds derivatives. IV. Di-... 

Most of the reactions of silicon or germanium organic compounds proceed photochemically via a radical mechanism or via a cycloaddition mechanism (Chapters 4 and 6). There are few examples of nucleophilic addition of RSi or RGe to Cgo [118,119]. Reaction of silyUithium derivatives RjSili or germyllithium derivatives RjGeLi with different alkyl- and aryl-substituents R yields mainly the 1,2-adduct 28 or the 1,16-adduct 29 1,4-addition and dimerization of two fullerene-units was also found as a minor pathway. One example is given in Scheme 3.15. 

Carbon is, of course, unique in the number of hydrides it forms, but the elements in the proximity of carbon in the Periodic Table have a similar, if more restricted, propensity to form hydrides. Silicon, germanium, boron and phosphorus are obvious examples. For hydrides of these elements, and especially for their organic derivatives, the methods of substitutive nomenclature can be applied to obtain suitable names. 

The synthesis of E Ge proved unequivocally that the germanium discovered by Winkler belong to Group IV of the Periodic Table and that it was identical to Mendeleev s eca-silicon. Consequently, Winkler was the forefather of both the new germanium element and also the chemistry of its organic derivatives, whereas Mendeleev was their Nostradamus. 

The formation of organic derivatives of penta- and hexacoordinate germanium is due to a later time when the reactions of organohalogermanes were studied with ammonia and amines (see Section ILF). When these reactions were conducted at low temperatures, 1 1 and 1 2 adducts were formed. When heated >0 °C, the complexes of organohalogermanes with ammonia, primary and secondary amines decomposed to give compounds... 

Organic derivatives of tin, germanium and lead were shown to be active against many fungal species, and derivatives of tetravalent metal proved to be the most toxic. Studies on... 

The chemistry of organic germanium, tin and lead compounds The chemistry of dienes and polyenes The chemistry of organic derivatives of gold and silver UPDATES... 

The organic derivatives of silicon, germanium, tin, and lead belong among the most stable and unreactive of organometallic compounds. They enjoy very great industrial importance, e.g., the Silicones, certain organotin compounds (as stabilizers for polyvinyl chloride), tetraethyllead (as anti-knock), etc.266... 

Tin forms organic derivatives of the same type as are obtained from silicon and germanium. However, the tin-carbon bond is very much more polar than that to silicon or germanium, so that attached organic groups are much more easily detached or replaced. Also the tendency to form complex compounds is greater.391... 

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