INVERTED SPIN-TRAPPING .3. FURTHER-STUDIES ON THE CHEMICAL AND PHOTOCHEMICAL OXIDATION OF SPIN TRAPS IN THE PRESENCE OF NUCLEOPHILES
INVERTED SPIN-TRAPPING .3. FURTHER-STUDIES ON THE CHEMICAL AND PHOTOCHEMICAL OXIDATION OF SPIN TRAPS IN THE PRESENCE OF NUCLEOPHILES
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DOI：
10.1039/p29940000171
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发表时间：
1994-02-01
期刊：
影响因子：
--
通讯作者：
EBERSON, L
中科院分区：
文献类型：
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作者：
EBERSON, L
用5.5-二甲基-1-吡咯烷-1-氧化物(DMPO)和3.3，5.5-四甲基-1-吡咯烷-1-氧化物(TMPO)作为ST的光化学反应，进一步探讨了自旋捕获自由基阳离子(St.+)与亲核试剂(Nu(-))之间的反应。结果表明，N-亚苄基叔丁胺N-氧化物(PBN)在弱电子受体四丁基钨钴酸铵(LII)和亲核试剂存在下的光激发产生相应的自旋加合物PbN-Nu(.)，很可能是通过中间自由基阳离子PbN+.环状N-氧化物DMPO和TMPO比PbN更难氧化(0.2-0.3V)。它们都利用热氧化和光化学氧化进行倒转自旋捕获，但比PBN有更多的限制。
Inverted spin trapping, denoting the reaction between the radical cation of a spin trap (ST.+) and a nucleophile (Nu(-)), has been further explored with respect to the photochemical generation of ST.+ and the use of 5.5-dimethyl-1-pyrroline 1-oxidet (DMPO) and 3.3,5.5-tetramethyl-1-pyrroline 1-oxide double dagger (TMPO) as ST. it is shown that photoexcitation of N-benzylidene-tert-butylamine N-oxide (PBN) in the presence of a weak electron acceptor, tetrabutylammonium 12-tungstocobaltate(lII), and a nucleophile gives the corresponding spin adducts, PBN-Nu(.), most likely via the intermediate radical cation PBN.+. This species could also be generated by sensitized photoxidation and made to react with Nu(-).The cyclic N-oxides DMPO and TMPO are more difficult to oxidize than PBN (by 0.2-0.3 V). They both engage in inverted spin trapping, using both thermal and photochemical oxidation, but in a more restricted way than for PBN.