[5]Helicene Based π-Conjugated Macrocycles with Persistent Figure-Eight and Möbius Shapes: Efficient Synthesis, Chiral Resolution and Bright Circularly Polarized Luminescence.

π-Conjugated chiral shape-persistent molecular nanocarbons hold great potential as chiroptical materials, though their synthesis remains a considerable challenge. Here, we present a simple approach using Suzuki coupling of a [5]helicene building block with various aromatic units, enabling the one-pot synthesis of a series of chiral macrocycles with persistent figure-eight and Möbius shapes. Single-crystal structures of 7 compounds were solved, and 22 enantiomers were separated by preparative chiral HPLC. A notable pyrene-bridged figure-eight macrocycle, with its rigid, fully π-conjugated and overcrowded structure, exhibited pure excimer emission and outstanding circularly polarized luminescence (CPL) properties, including a large dissymmetric factor (|g|=3.8×10) and significant CPL brightness (B=710.5 Mcm). This method provides a versatile synthetic platform for producing various chiral D-symmetric figure-eight macrocycles and singly or triply twisted Möbius macrocycles with C and D symmetry, offering tunable chiroptical properties for CPL applications.