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Durham University

Department of Chemistry

Publication details for Dr Robert Pal

Yeung, Chi-Tung, Yim, King-Him, Wong, Ho-Yin, Pal, Robert, Lo, Wai-Sum, Yan, Siu-Cheong, Yee-Man Wong, Melody, Yufit, Dmitry, Smiles, Danil E., McCormick, Laura J., Teat, Simon J., Shuh, David K., Wong, Wing-Tak & Law, Ga-Lai (2017). Chiral transcription in self-assembled tetrahedral Eu4L6 chiral cages displaying sizable circularly polarized luminescence. Nature Communications 8(1): 1128.

Author(s) from Durham

Abstract

Predictable stereoselective formation of supramolecular assembly is generally believed to be an important but complicated process. Here, we show that point chirality of a ligand decisively influences its supramolecular assembly behavior. We designed three closely related chiral ligands with different point chiralities, and observe their self-assembly into europium (Eu) tetrametallic tetrahedral cages. One ligand exhibits a highly diastereoselective assembly into homochiral (either ΔΔΔΔ or ΛΛΛΛ) Eu tetrahedral cages whereas the two other ligands, with two different approaches of loosened point chirality, lead to a significant breakdown of the diastereoselectivity to generate a mixture of (ΔΔΔΔ and ΛΛΛΛ) isomers. The cages are highly emissive (luminescence quantum yields of 16(1) to 18(1)%) and exhibit impressive circularly polarized luminescence properties (|glum|: up to 0.16). With in-depth studies, we present an example that correlates the nonlinear enhancement of the chiroptical response to the nonlinearity dependence on point chirality.