RESUMEN
Three-chromophore systems with light-harvesting behavior were prepared, which are based on periodic mesoporous organosilica (PMO) with crystal-like ordered structure. The organic bridges of biphenyl-PMO in the pore walls act as donors and two types of dye are incorporated in the one-dimensional channels. Consecutive two-step-Förster resonance energy transfer is observed from the biphenyl moieties to mediators (diethyl-aminocoumarin or aminoacridone), followed by energy transfer from mediators to acceptors (dibenzothiacarbocyanine, indodicarbocyanine, sulforhodamineâ G). High energy-transfer efficiencies ranging from 70 to 80 % are obtained for two-step-FRET, indicating that the mesochannel structure with one-dimensional ordering provides spatial arrangement of chromophore pairs for an efficient direct energy transfer. The emission wavelength can be tuned by a choice of acceptor dye: 477â nm (diethylaminocoumarin), 519â nm (aminoacridone), 567â nm (sulforhodamineâ G), 630â nm (dibenzothiacarbocyanine), and 692â nm (indodicarbocyanine).