Laser flash photolysis study of anthracene/viologen charge transfer complex in non-polar,dealuminated zeolites

摘要

A charge-transfer anthracene/viologen complex has been assembled within two purposely-prepared,non-polar Beta zeolite samples devoid of framework negative charge and positive cations.IR spectroscopy (absence of silanol groups),vapor adsorption (preferent n-hexane adsorption over water) and powder X ray diffraction (high crystallinity with minimum structural defects) indicate the "hydrophobic",low-polarity characteristics of the Beta zeolite samples used.Laser flash photolysis upon 532 nm selective excitation of the charge-transfer band shows that the photogenerated radical ions live hundreds of mus.This is the same time scale as for conventional,polar faujasites with high Al content.We suggest that in our non-polar zeolite the compartmentalized space and the ability of zeolites to participate in electron transfer processes are the main factors contributing to the remarkable lifetime increase of radical ions.