Formation of the Long-Lived Charge-Separated State of the 9-Mesityl-10-methylacridirtium Cation incorporated into Mesoporous Aluminosilicate at High Temperatures

摘要

The 9-mesityl-10-methylacidinium cation (Acr~+-Mes) was incorporated into Na~+-exchanged mesoporous aluminosilicate (A1MCM-41) by cation exchange. Incorporation of Acr~+-Mes into A1MCM-41 has made the lifetime of the electron-transfer (ET) state (Acr~·-Mes~(·+)) produced upon photoexdtation of Acr~+-Mes extremely long (e.g., 10 s) even at high temperatures (e.g., 373 K). The formation and decay of the ET state can be repeated by on—off photoirradiatiqn cycles. Both intra- and intermolecular back electron-transfer processes of the ET state of Acr~+-Mes were observed by electron spin resonance (ESR) and time-resolved nanosecond diffuse reflectance absorption spectra, respectively. The ET state has both strong oxidizing and reducing abilities to be able to oxidize neighboring 1-pyrenemethylammonium and reduce the hexyl viologen dication incorporated into AlMCM-41 by cation exchange, respectively.