Synthesis of Two Novel Optically Active #‐Shaped Cyclic Tetramers Based on Planar Chiral [2.2]Paracyclophanes. Issue 18 (21st February 2023)

• Record Type: Journal Article
• Authors: Morisaki, Aoi; Inoue, Ryo; Morisaki, Yasuhiro
• Is Part Of: Chemistry. Volume 29:Issue 18(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-21
• Subjects: circularly polarized luminescence -- cyclic oligomer -- [2.2]paracyclophane -- planar chirality; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202203533
• Languages: English
• ISSNs: 0947-6539

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. Abstract : Optically active #‐shaped cyclic tetramers, in which the p ‐arylene‐ethynylenes were stacked at the terminal benzene units, were synthesized. They composed of bis‐( para )‐pseudo‐ ortho ‐ and bis‐( para )‐pseudo‐ meta ‐tetrasubstituted [2.2]paracyclophanes. Two kinds of #‐shaped cyclic tetramers (parallel‐type and weave‐type) were formed depending on the π‐staked manner. The weave‐typed cyclic tetramer exhibited excellent CPL behavior with high g lum and B CPL values.