Discrete Macrocycles with Fixed Chirality and Two Distinct Sides: Dipole‐Dependent Chiroptical Response

Abstract

Control of symmetry is fundamental in molecular design with aimed properties. Herein we report a set of chiroptical C5‐symmetric molecules with variable dipolar structures based on a rim‐differentiated cylindrical macrocycle, pillar[5]arene. Incorporation of electron‐withdrawing ester groups formed an explicit two‐sided structure, leading to increase in response wavelength and luminescence efficiency. On the other hand, chiroptical measurement of separated enantiomers revealed that such a dipolar character diminished dissymmetry of the electronic transitions. By suppressing the dipole, the dissymmetry factor for luminescence was enhanced from 0.4×10−3 to 5.1×10−3 in a less dipolar methoxy‐substituted molecule, which was larger than reported pillar[5]arene derivatives without C5‐symmetry around one order of magnitude.