STUDY ON SINGLE-ELECTRON TRANSFER-REACTIO NS BETWEEN VARIOUS ACIDIC HYDROGERMANES AND SOME DIAMAGNETIC AND PARAMAGNETIC QUINONE SYSTEMS

The chlorogermanes PhnCl3-nGe-H (n = 0, 1, 2) were treated with diamag netic (3,5-di-t-butylorthoquinone) 1 and the paramagnetic galvinoxyl 2 . These reactions occur mainly by monoelectron transfer giving the cor responding adducts. In the case of 3,5-di-t-butylorthoquinone, the res ulting 1-4 adducts decompose by two simultaneous processes (HCl elimin ation and redistribution) yielding germadioxolanes. The chlorogermadio xolanes prepared in this way easily cause halogenic redistribution lea ding to chlorogermanes and germylcatecholates having branched or spira ne structure. In the case of the galvinoxyl radical, the same chloroge rmanes lead by monoelectron transfer to the corresponding quinophenol and an intermediate germanium-centered radical. The latter by recombin ation outside the solvent cage, gives digermane. However, its primary reaction, which occurs within the solvent cage, is with quinophenol to form two isometric O-and C-germylated catechols. The C-isomer is by f ar predominant as it also formed in the secondary hydrogermylation of quinophenol produced in the initial stage of the reaction. We have bee n able to confirm these mechanisms by a comparative study of the react ion of germanium hydrides R3Gedelta+-Hdelta-, acidic germanes X3Gedelt a--Hdelta+, and germanates X3Ge(-)N-H(+) with galvinoxyl and the corre sponding quinophenol.