Magnetic field effects on the decay rates of photogenerated geminate radical pairs in reversed micelles
Magnetic field effects on the decay rates of photogenerated geminate radical pairs in reversed micelles
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磁场对反胶束中光生双子自由基对衰减率的影响
DOI：
10.1021/j100362a012
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
T. Matsuo
中科院分区：
文献类型：
--
作者：
Akihiro Uehata;Hiroshi. Nakamura;S. Usui;T. Matsuo
激光（351nm）激发四苯基卟啉锌-紫外光对（AOT/异辛烷或正己烷）在笼中形成三重自由基对，外加磁场（0-1 T）显著延缓其衰变。在卟啉-紫胶连接化合物的情况下，自由基衰变率下降了一个数量级，在0.3 t以上达到平台区。在一个小的水池（约10{埃}半径）的反胶束中，由两亲性或阳离子卟啉和两性离子紫胶组成的非连接卟啉-紫胶对也观察到完全相同的行为。基于三重态的塞曼分裂和亚能级的电子自旋弛豫（弛豫机制）解释了外磁场对连接（或伪连接）自由基对的大影响，并通过顺磁性镧系离子的使用提供了支持证据。
Laser excitation (351 nm) of zinc tetraphenylporphinate-viologen pairs in reversed micelles (AOT/isooctane or n-hexane) afforded triplet radical pairs in a cage, and the decay was remarkably retarded in external magnetic fields (0-1 T). In the case of the porphyrin-viologen linked compound, the radical decay rate decreased by an order of magnitude to reach a plateau region at above 0.3 T. Exactly the same behavior was also observed with nonlinked porphyrin-viologen pairs, which consisted of amphiphilic or cationic porphyrin and a zwitterionic viologen, in a small water pool (ca. 10 {angstrom} in radius) of the reversed micelles. The large external magnetic field effects on the linked (or pseudolinked) radical pairs were explained on the basis of Zeeman splitting of the triplet in combination with electron spin relaxation from the sublevels (relaxation mechanism), and supporting evidence was provided by the use of paramagnetic lanthanide ions.