Studies on Other Hydroxylic Compounds

The 0—H bond of disubstituted hydroxylamine is, in general, easy to cleave homolytically since nitric oxide is produced, a radical well known for its high stability (Harle and Thomas, 1957 Buchachenko, 1962). Preparative evidence was given by Banfield and Kenyon (1926) by the production of a stable free radical in the mild oxidation of the corresponding N-phenyl-N-alkylhydroxylamine. 

The latter compound and its substituted derivatives readily react with polyvinyl acetate radicals. Substituents in the aromatic ring were found to influence the reactivity of the hydroxylamine slightly p = — 0-16 0-04 (Simonyi et al., 1967a). In comparing this value with those of phenols, the decreased substituent effect can be rationalized by considering two factors. First, the 0—H bond is more remote from the aromatic ring in hydroxylamine than in phenol. Second, the stability of phenyl nitroxide radicals is higher than that of phenoxy radicals. It is 

Recent direct observations confirm the early statements on the 

The possibility of abstracting a hydrogen atom from the carboxylic group may be expected to be even more limited than O—H bond fission of alcohols. The existence of the process was suggested to account for the decarboxylation of acids during the oxidation of hydrocarbons. The reactivity of the acidic hydrogen, however was estimated to be 100-times 

The hydrogen atom abstraction from oxalic acid by DPPH (Table 2, Singh et al., 1966) has already been commented upon. Carboxylic acids seem to be unsuitable models for studying radical reactivities of O—H bonds. 

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