Study of the structure of the anion-radicals of organosilicon compounds

Abstract

On the basis of the EPR spectra of the anion-radicals of 1,2-bis-(trirnethylsilyl)benzene, 9,9,10,10tetrarnethyl-9,10-disila-9,10-dihydroanthracene, and 9,10-disila-9,10-dihydroanthraeene, it has been concluded that there is insufficient justification for the idea, encountered in the literature, that delocalization of the unpaired electron between the two aromatic fragments in 9,9,10,10-tetrarnethyl-9,10-disila-9,10-dihydroanthracene is possible. The five-component EPR spectrum assigned to the anion-radicals of this compound may, in actual fact, belong to the anion-radicals of products of the splitting of this compound, of the same type as the organosilicon derivatives of diphenyl. The EPR spectra of the anion-radicals of ortho-trirnethylsilyltoluene, 9,9-dirnethyl-9-sila-9,10-dihydroanthraeene, and 9-sila-9,10-dihydroanthraeene indicate that when 9,9-dirnethyl-9-sila-9,10dihydroanthracene is reduced, it is converted into an organosilicon ketone. It is suggested that oxidation takes place through a stage involving the formation of the dianion-radical.