title: Light-harvesting three-chromophore systems based on biphenyl-bridged periodic mesoporous organosilica.
abstract: 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, sulforhodamine 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: 477 nm (diethylaminocoumarin), 519 nm (aminoacridone), 567 nm (sulforhodamine G), 630 nm (dibenzothiacarbocyanine), and 692 nm (indodicarbocyanine).
authors.affiliation: University of Hamburg, Institute of Inorganic Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany).
authors.forename: Lyubov
authors.initials: L
authors.lastname: Grösch
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Lee
authors.forename: Frank
authors.initials: F
authors.lastname: Hoffmann
authors.forename: Michael
authors.initials: M
authors.lastname: Fröba
keywords: chromophores; donor-acceptor systems; fluorescence spectroscopy; mesoporous materials; organic-inorganic hybrid