title: Synthesis of di- and trixanthones that display high stability and a visual fluorescence response to strong acid.
abstract: Three dixanthones (1-3) and an unprecedented C(3h)-symmetric trixanthone (4) were synthesized through a three-step approach in overall yields above 63%. These compounds possessed a planar π-conjugated system and formed tight face-to-face columnar stacks, as confirmed by single-crystal structural analysis. In comparison with xanthone, the fluorescence emissions of compounds 1-4 showed significant red-shifts, with improved quantum yields. Moreover, the fluorescence emissions of compounds 1-4 could be modulated in a strongly acidic environment without decomposition, which led to a further red-shift of the emissions, as well as enhancement of the emission intensities. These compounds have potential applications as optoelectronic materials and/or chemosensors.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Tianshui Southern Road 222, Lanzhou 730000, Gansu Province (China).
authors.forename: Baolin
authors.initials: B
authors.lastname: Wang
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Shao
authors.forename: Taoshan
authors.initials: T
authors.lastname: Xu
authors.forename: Lichuan
authors.initials: L
authors.lastname: Chen
authors.forename: Jinlian
authors.initials: J
authors.lastname: Zhao
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Shao
authors.forename: Hao-Li
authors.initials: HL
authors.lastname: Zhang
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Shao
mesh_terms: D018360:Crystallography, X-Ray; D019281:Dimerization; D058105:Polymerization; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D044004:Xanthones / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D044004:Xanthones
keywords: X-ray diffraction; conjugation; fluorescence; polycycles; xanthones