39058-87-2Relevant academic research and scientific papers
Generation of acyloxyl spin adducts from N-tert-butyl-a-phenylnitrone (PBN) and 4,5-dihydro-5,5-dimethylpyrrole 1-oxide (DMPO) via nonconventional mechanisms
Eberson, Lennart,Persson, Ola
, p. 1689 - 1696 (2007/10/03)
The reaction between N-tert-butyl-α-phenylnitrone (PBN) and carboxylic acids has been studied Two mechanisms are discernible: the generation of PBN+ by oxidation of PBN with a photochemically produced excited state [from either 2,4,6-tris(4-methoxyphenyl)pyrylium ion 2+ or tetrachlorobenzoquinone 4], followed by reaction with RCOOH, or the addition of RCOOH to PBN to give a hydroxylamine derivative, followed by thermal oxidation by a weak oxidant. The latter sequence is the Forrester-Hepburn mechanism. In this mechanism, neither 2+ nor 4 is effective as an oxidant, whereas bromine could be used. Thus only oxidants with redox potentials ≥ 0.1 (SCE) are reactive enough to oxidize the intermediate hydroxylamine. This behaviour is in agreement with the redox reactivity of hydroxylamines. For the cylic nitrone, 4,5-dihydro-5,5-dimethylpyrrole 1-oxide (DMPO), acyloxyl spin adducts have been prepared by the photochemical route. The reaction between dibenzoyl peroxide and PBN to give PhCOO-PBN is not cataysed by added PhCOOH. It could be shown that the rate of formation of PhCOO-PBN is compatible with the rate of thermal decomposition of dibenzoyl peroxide. Thus dibenzoyl peroxide does not support the Forrester-Hepburn mechanism, in agreement with its redox potential of ca. -0.2 V.
Spin Trapping of Peroxy Radicals by Phenyl-N-(tert-butyl)nitrone and Methyl-N-durylnitrone
Niki, Etsuo,Yokoi, Seiichi,Tsuchiya, Jyunichi,Kamiya, Yoshio
, p. 1498 - 1503 (2007/10/02)
The spin trapping of tert-butylperoxy and tetralylperoxy radicals by phenyl-N-(tert-butyl)nitrone (PBN) and methyl-N-durylnitrone (MDN) has been investigated.The peroxy radicals were generated by alkoxy radical induced decomposition of hydroperoxides, hydrogen atom abstraction from hydrocarbon in the presence of oxygen, and decomposition of hydroperoxydes by cobaltous ion and lead tetraacetate.The spin adducts of peroxy radicals were observed by ESR and their hyperfine splitting constants were detrmined.The spin adducts of peroxy radicals by MDN could be clearly distinguished from that of alkoxy radical.The nitrone spin adducts of oxygen radicals were found to be reasonably stable at room temperature in the dark, but they decayed readily in the ordinary laboratory light.
