Host-Guest Complexation-Induced Aggregation Based on Pyrene-Modified Cyclodextrins for Improved Electronic Circular Dichroism and Circularly Polarized Luminescence.

Several γ-cyclodextrin (CD) derivatives mono- or di-substituted by pyrenes at the primary rim of the CD were demonstrated to aggregate into nano-strips in aqueous solutions, with the pyrene moieties interpenetrating into γ-CD cavities. The hydrophobic complexation-induced aggregation provides a rigid chiral environment for the pyrenes and leads to significant electronic circular dichroism (ECD) and circularly polarized luminescence (CPL) activities, giving unprecedently high g abs and g lum values up to 4.3×10 -2 and 5.3×10 -2 , respectively. The aggregates lead to excimer emission with high quantum yields and show B CPL and B i CPL up to 338. 6 M -1  cm -1 and 169.3 M -1  cm -1 , respectively.