Reactions of Radicals with Germanium Hydrides

As with silicon hydrides, the reaction of atoms or radicals with germanium hydrides is the key step for the majority of reactions forming germyl radicals. However, kinetic data for the reactions of organic radicals with germanium hydrides in solution are limited to carbon- and oxygen-centered radicals. 

The kinetic data for these reactions are numerous, as shown in Table VI. Most of values were obtained by radical clock methods. The ring expansion of radical 7 has been employed as the clock in a study that provided much of the data in Table VI.74 Cyclizations of 5-hexenyl-type radicals also have been used as clocks,75-77 and other competition reactions have been used.78 Hydrogen atom abstraction from n-Bu3GeH by primary alkyl radicals containing a trimethylsilyl group in the a-, 8-, or y-position were obtained by the indirect method in competition with alkyl radical recombi- 

Rate Constants for Reactions, of Carbon-Centered Radicals with Germanium Hydrides 

Germane Radical Solvent Rate constant (M 1 s 2) (temp in °C as subscript) Rate expression (0 = 2.3RT kcal/mol) Ref. 

8 The value might be for a mixture of the cyclopropyl radical and its acyloxyl precursor see text. 

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