Detection of alkyl, alkoxyl, and alkyperoxyl radicals from the thermolysis of azobis(isobutyronitrile) by ESR/spin trapping. Evidence for double spin adducts from liquid-phase chromatography and mass spectroscopy

• Published in: Journal of the American Chemical Society Vol. 112; no. 23; pp. 8279 - 8284
• Main Authors: Janzen, Edward G, Krygsman, Peter H, Lindsay, David A, Haire, D. Larry
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.11.1990
• Subjects: 400102 - Chemical & Spectral Procedures; 400201 - Chemical & Physicochemical Properties; ALKOXY RADICALS; ALKYL RADICALS; AZOLES; CARBON 13; CARBON ISOTOPES; CHEMICAL REACTIONS; Chemistry; CHROMATOGRAPHY; DECOMPOSITION; ELECTRON SPIN RESONANCE; ELEMENTS; EVEN-ODD NUCLEI; Exact sciences and technology; Free radicals chemistry; HETEROCYCLIC COMPOUNDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ISOTOPES; LABELLED COMPOUNDS; LIGHT NUCLEI; LIQUID COLUMN CHROMATOGRAPHY; MAGNETIC RESONANCE; MASS SPECTROSCOPY; NITRILES; NONMETALS; NUCLEI; Organic chemistry; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; ORGANIC OXYGEN COMPOUNDS; OXYGEN; PEROXY RADICALS; PYROLYSIS; PYRROLES; RADICALS; Reactivity and mechanisms; RESONANCE; SEPARATION PROCESSES; SPECTROSCOPY; STABLE ISOTOPES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE; TEMPERATURE RANGE 0065-0273 K; THERMOCHEMICAL PROCESSES; Azo compound; Pyrolysis; Organic free radical; Spin trapping; EPR spectrometry; Dinitrile
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja00179a010

The thermolysis of azobis(isobutyronitrile) (AIBN) in the presence of oxygen has been investigated by spin trapping by using {alpha}-phenyl N-tert-butyl nitrone (PBN) and 5,5-dimethylpyrroline N-oxide (DMPO). The aminoxyl products identified by ESR and mass spectroscopy (MS) are the results of trapping 2-cyano-2-propyl radicals (CP{sup {sm bullet}}) in the presence of oxygen. By low-temperature ESR the 2-cyano-2-propylperoxyl adduct or PBN-nitronyl-{sup 13}C is detectable in the presence of oxygen. The mass spectrum of the alkoxyl adduct is detectable only by the use of liquid chromatography/mass spectroscopy (LC/MS). The alkoxylamines, the C-(2-cyano-2-propyloxyl), O-(2-cyano-2-propyl) mixed double adducts of PBN (CPO-PBN-CP) and DMPO (CPO-DMPO-CP), have been observed for the first time. The normal double adducts, CP-PBN-CP or CP-DMPO-CP, are not detected.