Influence of the Alkali Metal Cation on the Distance of Electron Migration in Zeolite Y: A Nanosecond Laser Photolysis Study

Abstract

Zeolites have been identified as promising solid-state host materials for the design of alternative energy systems due to their ability to promote long-lived charge-separated states. Herein we investigate the ability of alkali metal cation-exchanged Y zeolites to mediate the formation of a spatially separated radical cation/radical anion pair by photoinduced electron migration. The chosen system is the electron-transfer reaction between photoexcited trans-anethole and co-incorporated 1,4-dicyanobenzene taking place within the internal cavities of the Y zeolite. The results from the investigation show that varying the alkali metal cation within the Y zeolite framework significantly influences the distance of electron migration and that the electrons travel farthest within dry NaY as compared to the other alkali metal cation-exchanged Y zeolites. The presence of intrazeolite water was also found to impede electron migration within the zeolite matrix.