- 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
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 (|g lum|: 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.