Hexacoordinate germanium complexes

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... 

Quite recently, it was established that the formation of the pentacoordinated germanium and tin compounds EF4(CH2CH=CH2) from EF3(CH2CH=CH2) (E = Ge, Sn) by the addition of F is exothermic148. The nucleophilicity of the allylic y-carbon is much enhanced when the pentacoordinated EF4(CH2CH=CH2) is formed. These results are qualitatively similar to those found for the reaction of the corresponding silicon compound. The pentacoordinated Ge and Sn complexes have a significant Lewis acidity which allows them to form stable hexacoordinated intermediates in the course of the reaction. 

Hypervalent compounds of organic germanium, tin and lead derivatives 1149 IX. HEXACOORDINATE ANIONIC COMPOUNDS A. Intermolecular Complexes... 

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