Binaphthyl–Bipyridyl Cyclic Dyads as a Chiroptical Switch

• DOI: 10.1021/jacs.8b01860
• Publication Date: 2018-04-13T16:49:11Z
• Authors: Kazuto Takaishi; Makoto Yasui; Tadashi Ema
• Keywords: Axial symmetry; Structural isomer; Dyad

A series of chiral cyclic dyads, axially binaphthyls linked to a 3,3′-bipyridyl, was synthesized. The dyad 2 bearing methoxy groups exhibited ON/OFF properties in circularly polarized luminescence (CPL), yielding |glum| 1.6 × 10–3 or 0 without any change fluorescence. This type CPL switch is unprecedented. Regioisomer 4 dextro/levo rotation switching ability [α]D. X-ray structures as well experimental and theoretical analyses suggested that the depended on conformational changes.