N-取代酰胺-二苯酮体系光化夺氢反应活泼自由基的ESR研究

本文用自由基捕捉剂2,3,5,6-四甲基亚硝基苯(ND)及苯亚甲基叔丁基氮氧化物(PBN)与ESR相结合的方法研究了十二种取代酰胺RC₆H₄NHC(0)CH₃(R-CH₃、Cl、Br、H、NO₂)、C₆H₅N(R)C(0)CH₃(R=CH₃、C₂H₅)及HC(0)NR₂(R-CH₃、C₂H₅)与二苯酮光化夺氢反应中的活泼自由基。结果表明: 1.对于RC₆H₄NHC(0)CH₃,二苯酮夺取氮上H形成R-C₆H₄NC(0)CH₃自由基。 2.对C₆H₅N(R)C(0)CH₃及HC(O)NR₂,二苯酮夺取与羰基相连的甲基氢、羰基上氢及与N相连碳上的氢分别形成 C₆H₅N(R)C(0)CH₂、C(0)NR₂、C₆H₅N(CHR')C(0)CH₃及。

ESR STUDY ON THE FREE RADICALS IN THE PHOTOCHEMICAL HYDROGEN ABSTRACTION REACTION BETWEEN THE N-SUBSTITUTED AMIDE AND BENZOPHENONE

By use of spin trapping reagents, 2, 3,5,6-four metyl nitrosobenzene and phenyl t-butyl nitrone, in combination with ESR technique, the active free radicals were studied in the photochemical hydrogen abstraction reaction between benzophenone and twelve substituted amides, RC6H4NHC(O)CH3 (R = CH3, CI, Br, H, NO2 ) , C6H5N(R)C(O)CH3 or HC(O)NR2(R = CH3, C2H5). The results show that: ( 1 ) for RC6H4NHC(O)CH3,benzophenone abstracts H from nitrogen to form RC6H4NC(O)CH3. (2)for C6H5N(R)C(O)CH3 or HC(O)NR2,benzophenone adstracts H from the methyl group linked with the carbonyl,from the carbony or from the carbon linked with nitrogen, respectively,to form C6H5N(R) C(O)CH2, C(O)NR2,C6H5N (CHR')C(O) CH3 or HC(O)NR (R' = H, CH3).