New [2, 2]Fluorenophanes Give Insights into Asymmetric Charge Transfer‐Mediated Exciton Delocalization along the π‐π Packing Direction. Issue 34 (13th May 2021)

• Record Type: Journal Article
• Authors: Wang, Chi‐Shin; Wei, Yu‐Chen; Pan, Ming‐Lun; Wu, Cheng‐Ham; Chou, Pi‐Tai; Wu, Yao‐Ting
• Is Part Of: Chemistry. Volume 27:Issue 34(2021)
• Page Start: 8678
• Page End: 8683
• Publication Date: 2021-05-13
• Subjects: charge transfer-mediated excitons -- cyclophane -- dual fluorescence -- mechanochromism -- pi-pi interactions; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202100234
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A series of new [2, 2]fluorenophanes has been synthesized and characterized; among them, molecules of crystallographically asymmetric anti ‐[2.2](1, 4)(4, 1)fluorenophane (K2C ‐2) aggregate to form one‐dimensional supramolecular chain structures through effective intermolecular π‐π overlapping. This, in combination with the synergistic intramolecular π‐π interaction, leads to prominent dual emission mediated by charge transfer (CT) exciton delocalization. Support of this new insight is given by mapping the transition density along the π‐π packing direction where the intramolecular excitation and intermolecular CT coexist in K2C ‐2. Abstract : Excitation, delocalization, emission : Molecules of crystallographically asymmetric anti ‐[2.2](1, 4)(4, 1)fluorenophane (K2C ‐2) aggregate to form one‐dimensional supramolecular chain structures through effective intermolecular π‐π overlapping. Crystals exhibit prominent dual emission caused by the intramolecular excitation and intermolecular charge transfer‐mediated exciton delocalization along the π‐π packing direction.