Feb., 1939 REACTIONS OF ARYL GRIGNARD REAGENTS WITH SILICON HALIDES 363 of the oxidation only the formation is essential, which might well be followed by a decomposition whenever two molecules of the intermediate collide. With hydroquinone itself and its homologs, no compound of the type in question has been described. The suggestion that the semiquinone-quinone complex does not exist with the tetramethyl compound and ...