Electrochemistry of metalloporphyrins and viologens at zeolite Y-modified electrodes: evidence for electron trapping by monomolecular porphyrin layers
Electrochemistry of metalloporphyrins and viologens at zeolite Y-modified electrodes: evidence for electron trapping by monomolecular porphyrin layers
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DOI：
10.1021/j100320a039
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Zhuying Li;C. Wang;L. Persaud;T. Mallouk
中科院分区：
文献类型：
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作者：
Zhuying Li;C. Wang;L. Persaud;T. Mallouk
本文给出了含卟啉和紫精的Y型沸石粉涂电极的循环伏安数据。紫精阳离子（甲基紫精、苄基紫精或N，N '-（1，3-丙烯基）-2，2'-联吡啶）的半波电位在交换到沸石Y中时没有显著变化，而钴和锌四（N-甲基-4-吡啶基）卟啉的还原电位（相对于水溶液）移动了+200 mV。当紫精阳离子被离子交换到大部分的沸石，钴四（N-甲基-4-吡啶基）卟啉被吸附到其外表面上的单层量，电流整流和电荷捕获反应进行观察。的电荷untrapping反应是类似于先前观察到的氧化还原聚合物双层电极，并归因于一个动力学快速交叉反应的沸石和钴（II）卟啉的外表面上的双还原紫精内。旋转盘实验表明，卟啉单层有效地密封了沸石对交换封装紫精与溶液相阳离子。
Cyclic voltammetric data are presented for electrodes coated with zeolite Y powder containing porphyrins and viologens. Half-wave potentials for viologen cations (methylviologen, benzylviologen, or N,N'-(1,3-propenyl)-2,2'-bipyridinium) do not change significantly when they are exchanged into zeolite Y, whereas the reduction potentials for cobalt and zinc tetrakis(N-methyl-4-pyridyl)porphyrins shift (relative to aqueous solution) by + 200 mV. When a viologen cation is ion exchanged into the bulk of the zeolite, and cobalt tetrakis(N-methyl-4-pyridyl)porphyrin is adsorbed onto its outer surface in monolayer quantities, current rectification and charge trapping reactions are observed. The charge untrapping reactions are similar to those previously observed at redox polymer bilayer electrodes and are attributed to a kinetically fast cross reaction between double reduced viologens inside the zeolite and cobalt(II)porphyrin on the outer surface. Rotating disk experiments show that the porphyrin monolayer effectively seals up the zeolite against exchange of encapsulated viologens with solution-phase cations.