Injecting Electronic Excitation Energy into an Artificial Antenna System through an Ru2+ Complex

Abstract

The Ru²⁺ complex [Ru(bpy)₂(bpy-ph₄-Si(CH₃)₃)]²⁺ can be electrostatically bound to the negatively charged channel entrances of dye-loaded zeolite L crystals where it acts as a functional stopcock molecule. Impressive electronic triplet–singlet excitation energy transfer from the Ru²⁺ complex to the acceptor dye oxazine 1 (Ox1) located inside the channels can be observed when the donor molecule is selectively excited. Time-resolved luminescence experiments have been performed on the separate components and on the assembled donor–acceptor material. The luminescence lifetime of the Ru²⁺ complex attached to the zeolite is reduced by a factor of 30 when Ox1 acceptor molecules are present. The fluorescence decay of Ox1 incorporated in zeolite L is single exponential with a lifetime of 3 ns. The much longer lifetime in zeolite L than in solution is due to the fact, that the diethyl groups are sterically restricted when the dye is inside the host.