Dye-loaded zeolite L sandwiches as artificial antenna systems for light transport

The synthesis and characterization of dye loaded zeolite L sandwiches actin g as artificial antenna systems for light harvesting and transport is repor ted. A set of experimental tools for the preparation of neutral dye-zeolite L materials ranging from low to maximum packing densities has been develop ed. The role of co-adsorbed water and the distribution of molecules between the inner and the outer surface were found to be the determining parameter s. p-Terphenyl (pTP) turned out to be very suitable for studying these and other relevant parameters of neutral dye-zeolite L materials. We observed t hat pTP located in the channels of zeolite L can reversibly be displaced by water. This can be used when synthesizing such materials. We also observed that all-trans-1,6-diphenyl-1,3,5-hexatrirne (DPH) which is very photolabi le in solution is stable after insertion into zeolite L. By combining our e xtensive knowledge of these systems with ion-exchange procedures developed in an earlier study, we have realized the first bi-directional three-dye an tenna. In this material the near UV absorbing compounds DPH or 1,2-bis-(5 - methyl-benzoxazol-2-yl)-ethene (MBOXE) are located in the middle part of ze olite L nanocrystals followed on both sides by pyronine (Fy) and then by ox onine (Ox) as accepters. Fluorescence of the oxonine located at both ends o f the cylindrical zeolite L crystals was observed upon excitation of the ne ar UV absorber in the middle section at 353 nm, where neither oxonine nor p yronine absorb a significant amount of the excitation light.