Characterization of a Stable 2,2′-Azobis(2-Methylpropanenitrile) Degradant and Its Use to Monitor the Oxidative Environment During Forced Degradation Studies by Liquid Chromatography/Mass Spectrometry
Azo compounds are commonly used to study radical-mediated degradation of pharmaceutical compounds. The favorable chemical and physical properties of 2,2′-azobis(2-methylpropanenitrile) (AIBN) have made it one of the most widely used compound for these type of studies. This article describes the characterization of a stable product, N-(1-cyano-1-methylethyl)-2-methylpropanamide, formed during the decomposition of AIBN. This product is easily detected by liquid chromatography/mass spectrometry and can serve as a marker to confirm the AIBN is working as intended and to monitor the kinetic formation of free radical species.
Surface Photochemistry: Decomposition of Azobis(isobutyronitrile) on Dry Silica Gel
The generation of cyanopropyl radical pairs by the photolysis of azobis(isobutyronitrile) (AIBN) adsorbed on dry silica gel-benzene slurries has been investigated.The results require revision of an earlier observation that restrictions on the rotational motion of cyanopropyl radicals at a silica gel-benzene interface prevented the formation of the unsymmetrical coupling product dimethyl-N-(2-cyano-2-propyl)ketenimine.Both tetramethylsuccinodinitrile and the ketenimine were formed on the silica gel surface, even when dry, although the latter was partially hydrolyzed to the corresponding amide.Measurements of geminate recombination of radicals produced by direct photolysis of mixtures of deuterated and nondeuterated AIBN indicated that some radicals could escape, by translational motion, from their original geminate partners.The amount of translational motion was increased for the same cyanopropyl radical pair generated by triplet-sensitized AIBN decomposition.This latter observation supports the view that the triplet-sensitized decomposition of AIBN occurs directly from an exited state rather than by isomerization to a thermally labile cis isomer.
Johnston, Linda J.,Mayo, Paul de,Wong, S. King
p. 20 - 26
(2007/10/02)
Surface Photochemistry: Evidence for Rotational and Translational Movement of Cyanopropyl Radicals on a Silica Gel Surface
The photolysis of azoisobutyronitrile is shown to generate radicals which, contrary to an earlier report, undergo rotational and translational movement on a silica gel surface.
Johnston, Linda J.,Mayo, Paul de,Wong, S. King
p. 1106 - 1108
(2007/10/02)
More Articles about upstream products of 84213-57-0