Binaphthyl‐Bridged Pyrenophanes: Intense Circularly Polarized Luminescence Based on a D2 Symmetry Strategy. (12th May 2022)

• Record Type: Journal Article
• Authors: Takaishi, Kazuto; Murakami, Sho; Yoshinami, Fumiya; Ema, Tadashi
• Is Part Of: Angewandte Chemie. Volume 134:Number 27(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-12
• Subjects: Axial Chirality -- Biaryls -- Circularly Polarized Luminescence -- Conformation Analysis -- Excimers; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202204609
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A series of D 2 ‐symmetric macrocycles composed of alternately linked pyrene and binaphthyl moieties (binaphthyl‐bridged pyrenophanes) have been synthesized. Among them, a pyrenophane possessing ether linkers at the 2, 7‐positions of the pyrenes exhibited intense circularly polarized luminescence (CPL) with a | g lum | value of 0.053. This value is by far the highest for excimers and was not sensitive to temperature, solvent, or concentration. The CPL originated from a twisting pyrene excimer, with the ( R )‐binaphthyl moieties producing a left‐handed twist excimer, which exhibited (−)‐CPL. The electric and magnetic transition dipole moments are perfectly parallel, which is the best relationship for strong CPL. Abstract : D 2 ‐symmetric binaphthyl‐bridged pyrenophanes have been synthesized with face‐to‐face pyrene rings. Matching the type and position of the linkers led to the pyrenophane exhibiting intense circularly polarized luminescence with a | g lum | value reaching 0.053. This effect arose because of the D 2 symmetry of the dye, which resulted in the binaphthyl moieties producing a unidirectionally twisting pyrene excimer with completely parallel electric and magnetic transition dipole moments.