Control of Circularly Polarized Luminescence by Orientation of Stacked π‐Electron Systems.

Planar chiral building blocks based on 4,7,12,15‐tetrasubstituted [2.2]paracyclophanes were obtained via a synthetic route involving an optical resolution step. Planar chiral enantiomers, comprising two fluorophores that were stacked to form a V‐shaped higher‐ordered structure, were synthesized from these building blocks. The V‐shaped molecules emitted intense circularly polarized luminescence (CPL). Their chiroptical properties were compared with those of X‐shaped molecules bearing the same two fluorophores stacked together. The CPL sign of the X‐shaped molecule was opposite to that of the V‐shaped molecule, which is supported by the theoretical results, indicating that the CPL sign can be controlled by the orientation of the stacked fluorophores. [ABSTRACT FROM AUTHOR]