Photoionization of tetraphenylporphyrin in mesoporous SiMCM-48, AlMCM-48, and TiMCM-48 molecular sieves
Photoionization of tetraphenylporphyrin in mesoporous SiMCM-48, AlMCM-48, and TiMCM-48 molecular sieves
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DOI：
10.1021/la011414o
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发表时间：
2002-02-05
期刊：
影响因子：
3.9
通讯作者：
Kevan, L
中科院分区：
文献类型：
--
作者：
Chang, ZX;Kevan, L
用电子自旋共振技术测定了介孔分子筛SiMCM-48、AlMCM-48和TiMCM-48中孔分子筛中四苯基卟啉(H_2TPP)的光致电离产率。在室温下，MCM-48材料是实现大体积卟啉分子长寿命光诱导电子转移的有效非均相载体。TiMCM-48和AlMCM-48具有比SiMCM-48更高的H_2TPP(+)自由基的光产率，表明Al和Ti的引入增强了骨架的电子接受能力。在TiMCM-48中，H_2TPP+自由基比在SiMCM-48和AlMCM-48中更稳定。
Electron spin resonance spectroscopy has been used to detect the photoionization yield of meso-tetraphenylporphyrin (H2TPP) in SiMCM-48, AlMCM-48, and TiMCM-48 mesoporous molecular sieves. MCM-48 materials are shown to be effective heterogeneous hosts to accomplish long-lived photoinduced electron transfer of bulky porphyrin molecules at room temperature. TiMCM-48 and AlMCM-48 have higher photoyields of H2TPP(+) radicals than does SiMCM-48, indicating that the incorporation of Al and Ti into MCM-48 frameworks enhances the electron-accepting ability of the framework. H2TPP+ radicals are more stable in TiMCM-48 than in SiMCM-48 and AlMCM-48.