A colour-tunable chiral AIEgen: reversible coordination, enantiomer discrimination and morphology visualization. Issue 9 (16th June 2016)

• Record Type: Journal Article
• Authors: Roose, Jesse; Leung, Anakin Chun Sing; Wang, Jia; Peng, Qian; Sung, Herman H.-Y.; Williams, Ian Duncan; Tang, Ben Zhong
• Is Part Of: Chemical science. Volume 7:Issue 9(2016:Sep.)
• Page Start: 6106
• Page End: 6114
• Publication Date: 2016-06-16
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6sc01614f
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : We present a chiral red-fluorescent AIEgen that reversibly coordinates nucleophiles with large changes in optical properties. This effect is used to discriminate enantiomers and analyse the micro-morphology of polymer blends. Abstract : We present a conceptually new approach to synthesise a boron-containing Aggregation-Induced Emissive Luminogen (AIEgen) with a chiral chromophore. An intramolecular N–B coordinating bond results in a low-energy transition that renders the material red-emissive in a solid state. By competitive binding of nucleophiles to the boron atom, this bond is replaced in favour of an intermolecular coordinating bond, which results in a tremendous blue-shift in both the absorption and emission. A supportive DFT computation elucidates that a breakage of the intramolecular N–B coordinating bond causes a tremendous loss of conjugation in the LUMO, resulting in a larger energy gap. Owing to the fact that our scaffold is intrinsically chiral and Lewis-acidic, we demonstrate how our AIEgen discriminates between two pairs of enantiomers in a simple UV-vis measurement. Furthermore, the binding capabilities are exploited to stain polymer blends that comprised a non-coordinating and a Lewis-basic polymer. The red fluorescence that originates only from domains of the non-coordinating polymer is conveniently detected by a fluorescence microscope. Thus, compared to current analytical methods, we present a cheaper and faster methodology to study the micro-morphologies of certain polymer blends.