Photoswitching of dextro/levo rotation with axially chiral binaphthyls linked to an azobenzene.
To examine the reversible photoisomerization and subsequent change of asymmetric field, we synthesized optically active 3,3'-disubstituted-1,1'-binaphthyls with an azobenzene moiety. Reflecting the structural change, the specific rotation and circular dichroism underwent significant variations. Under certain conditions, the positive-negative signals were reversible. Furthermore, the magnitude of these changes showed a 3,3'-substituent dependency. Dibenzyloxy or bis(diphenylmethyloxy) derivatives were better suited for sign interconversion of the optical properties. In contrast, the hydroxy group(s) lacked both optical signals and durability.
Takaishi
Kazuto
K
Supramolecular Science Laboratory, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198, Japan. ktakaishi@riken.jp
Kawamoto
Masuki
M
Tsubaki
Kazunori
K
Wada
Tatsuo
T