Radical reactions in the co‐ordination sphere of transition metals. XIIIRadicals derived from 4,4′‐ and 2,2′‐Alkylidenebisphenolic Antioxidants

Radical species were generated from 4,4′;‐ and 2,2′;‐alkylidenebisphenols during oxidation with free and co‐ordinated [Co(III)]RO2˙Radicals. This simulates the participation of bisphenolic antioxidants in the process of stabilization of hydrocarbons. Phenoxyls are primarily formed, and, depending on the character of the alkylidene bridge, some of them are gradually transformed into phenoxy radicals of the galvinoxyl type. Oxidation of alkylidenebisphenols by oxygen complexed to Co(II) yields co‐ordinated cyclohexadienonyloxy radicals. The character of the alkyl substituents on the phenolic nuclei specifically influences the stability of the generated phenoxy radicals at the applied temperature. The ESR characteristics of the primarily formed phenoxyls, phenoxyls of the galvinoxyl type and co‐ordinated cyclohexadienonyloxyls are discussed.