Synthesis of Two Novel Optically Active #‐Shaped Cyclic Tetramers Based on Planar Chiral [2.2]Paracyclophanes
Aoi Morisaki, Ryo Inoue, Yasuhiro Morisaki
Abstract
Abstract This study reports the synthesis of optically active cyclic tetramers comprising four stacked π‐electron systems from two enantiomerically pure [2.2]paracyclophane compounds (bis‐( para )‐pseudo‐ ortho ‐ and bis‐( para )‐pseudo‐ meta ‐tetrasubstituted [2.2]paracyclophane compounds). Depending on the combination of the absolute configurations of the planar chiral pseudo‐ ortho ‐ and pseudo‐ meta ‐[2.2]paracyclophane units, the cyclic tetramers formed either parallel‐#‐ or weave‐#‐structures. The optical and chiroptical properties of both structures were investigated experimentally and theoretically. In particular, the weave‐#‐shaped cyclic tetramer exhibited good chiroptical properties and emitted circularly polarized luminescence (CPL) with a high anisotropy factor (| g lum | value of the order of 10 −3 ) and a CPL brightness ( B CPL ) higher than 100.