Multiply Twisted Chiral Macrocycles Clamped by Tethered Binaphthyls Exhibiting High Circularly Polarized Luminescence Brightness.
Masashi HasegawaChika HasegawaYuki NagayaKazunori TsubakiYasuhiro MazakiPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2022)
Chiral macrocyclic dimers, trimers, and tetramers composed of paraphenylene and tethered binaphthyl were synthesized, and their molecular structures and chiroptical properties were investigated. X-ray analysis and theoretical calculations revealed that multiple twisted molecular structures - dimers, trimers, and tetramers - adopt figure-of-eight, Möbius triangle, and concave rectangle structures, respectively. These homologues have large ϵ values in their UV-vis absorption spectra because of the π-conjugation of the naphthalene-phenylene-naphthalene frameworks. Owing to the shape-persistent ring structure and tethering with -OCH 2 CH 2 O-, high fluorescence quantum yields and a relatively high dissymmetry factor g CPL in circularly polarized luminescence (CPL) spectra were achieved. This results in CPL brightness (B CPL ) of over 100, which is greater than that of the conventional organic CPL dye.