title: Fluorescent dyes with directly connected xanthone and xanthene units.
abstract: Unexpected dimerization of a methoxymethyl-protected xanthone occurred upon treatment with an aryl lithium reagent generated from 2-bromo-1,3-dimethylbenzene and n-butyllithium. The hydrogen between two directing ethereal oxygen atoms was not abstracted, but that adjacent to the carbonyl group was removed to afford a dimeric compound containing two directly connected fluorescent xanthone and xanthene units. Starting from this discovery, three dimeric dyes were constructed, and their optical properties were examined. Although the two fluorescent units were orthogonal in each dye, efficient energy transfer was observed in dimeric dye 16 in three solvent systems. In contrast, solvent-dependent energy transfer was detected for another dimeric dye, 5. After close investigation, we found that the orientation factor (κ) is the main factor influencing Förster resonance energy transfer in these dyes.
authors: Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
authors: Akane
authors: A
authors: Katori
authors: Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
authors: Eriko
authors: E
authors: Azuma
authors: Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
authors: Hina
authors: H
authors: Ishimura
authors: Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
authors: Kouji
authors: K
authors: Kuramochi
authors: Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
authors: Kazunori
authors: K
authors: Tsubaki
mesh_terms: D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D015394:Molecular Structure; D014966:Xanthenes / Q000737:chemistry*; D044004:Xanthones / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D014966:Xanthenes; D044004:Xanthones; C009689:xanthone