28958-67-0Relevant academic research and scientific papers
UV-vis monitoring of radical polymerizations by spin trapping with chromophoric nitrones
Husmann, Ralph,Wertz, Sebastian,Daniliuc, Constantin G.,Schaefer, Sascha W.,McArdle, Ciaran B.,Studer, Armido
, p. 993 - 1000 (2014/03/21)
The application of chromophoric radical spin traps for highly sensitive UV-vis monitoring of conversion of radical enhanced spin capturing polymerizations (ESCP) is presented. In ESCP the growing macroradical is reacting with a nitrone providing the corresponding polymeric nitroxide radical spin trap which will react irreversibly with a second macroradical to eventually give a polymeric alkoxyamine. The progress of styrene and n-butyl acrylate ESC polymerizations in the presence of π-conjugated nitrones is successfully visualized via a significant change of absorbance of the nitrone chromophore in the 200-500 nm range due to the nitrone transformation into an alkoxyamine moiety upon incorporation into the polymer. Moreover, related studies on UV-vis monitoring of photochemical rearrangement of nitrones to their corresponding oxaziridines are discussed.
Autoxidation Reactions of Imines to form Oxaziridines and Amides
Auret, Barbara J.,Boyd, Derek R.,Coulter, Peter B.
, p. 463 - 464 (2007/10/02)
The formation of oxaziridines and the isomeric amides in equal amounts by the spontaneous autoxidation of several liquid imines via peroxyimidic acid intermediates is reported.
Relative Conjugative Abilities of Three-Membered Ring Heterocycles with Benzene Based on 13C and 15N NMR
Crist, DeLanson R.,Jordan, Guy J.,Moore, Donald W.,Hashmall, Joseph A.,Borsetti, Arnold P.,Turujman, Saleh A.
, p. 4136 - 4142 (2007/10/02)
The conjugative ability of various three-membered rings with benzene was investigated by observing the sensitivity of β-carbon 13C chemical shifts to para substituents.These Hammett ρ values were 2.0, 1.5, 1.0, and 0.9 ppm for arylcyclopropanes, N-methyl-2-arylaziridines, phenyloxiranes, and N,N-dimethyl-2-arylaziridinium fluorosulfonates, respectively.These values were intermediate to ones for para-substituted styrenes (6.5 ppm) and ethylbenzenes (-0.9 ppm), model compounds which were taken to represent extremes of conjugative ability.Similar results were found for 15N chemical shifts of trans-3-aryl-oxaziridines, which had a slope of 2.1 ppm, intermediate to those for benzylimines (20.2 ppm) and benzylamines (-1.3 ppm).The order of conjugative ability, which decreases with increasing electronegativity of the hetero group, could not be explained by hybridization changes based on comparing open chain analoques with the above compounds or by conformational factors.The trend can, however, be interpreted qualitatively by perturbation theory which shows that more electronegative hetero groups decrease the extent of interaction between aryl-? and cyclopropane orbitals as well as cross ring conjugation.
The Mechanisms of the Conversion of Thiophosphoryl Compounds into their Phosphoryl Analogues by Photochemically Excited 3-Methylpyridazine 2-Oxide and by 2-Methyl-3-p-nitrophenyloxaziridine; a Comparison
Rowley, Alan G.,Steedman, John R. F.
, p. 1113 - 1120 (2007/10/02)
Reactions of tri-p-substituted triarylphosphine sulphides with 3-methylpyridazine 2-oxide, under photolysis, and with 2-methyl-3-p-nitrophenyloxaziridine both give the corresponding phosphine oxides.A detailed study and comparison of the two reactions shows that they are mechanistically quite distinct and that it is unlikely that the active oxygenating species generated by photolysis of the N-oxide, which attacks the phosphine sulphides, is an oxaziridine.The evidence presented suggests that this species may in fact be 'oxene'.
