title: Color-tunable, aggregation-induced emission of a butterfly-shaped molecule comprising a pyran skeleton and two cholesteryl wings.
abstract: A chiral pyran derivative containing two cholesteryl groups (1) is synthesized, and its optical properties are investigated. Whereas the isolated molecule of 1 is virtually nonluminescent in dilute solutions, it becomes highly emissive with a 2 orders of magnitude increase in fluorescence quantum yield upon aggregation in poor solvents or in solid state, showing a novel phenomenon of aggregation-induced emission (AIE). The color and efficiency of the AIE of 1 can be tuned by varying the morphology of its aggregates: photoluminescence of its aggregates formed in a tetrahydrofuran/water mixture progressively red-shifts (green --> yellow --> red) with increasing water content of the mixture, with the crystalline aggregates emitting bluer lights in higher efficiencies than their amorphous counterparts.
authors.affiliation: Departments of Chemistry and Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Tong
authors.forename: Yuning
authors.initials: Y
authors.lastname: Hong
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Dong
authors.forename: Yan
authors.initials: Y
authors.lastname: Ren
authors.forename: Matthias
authors.initials: M
authors.lastname: Häussler
authors.forename: Jacky W Y
authors.initials: JW
authors.lastname: Lam
authors.forename: Kam Sing
authors.initials: KS
authors.lastname: Wong
authors.forename: Ben Zhong
authors.initials: BZ
authors.lastname: Tang