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Abstract Whether tetra‐tert‐butyl‐s‐indacene is a symmetricD2hstructure or a bond‐alternatingC2hstructure remains a standing puzzle. Close agreement between experimental and computed proton chemical shifts based on minima structures optimized at the M06‐2X, ωB97X‐D, and M11 levels confirm a bond‐localizedC2hsymmetry, which is consistent with the expected strong antiaromaticity of TtB‐s‐indacene.
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This content will become publicly available on December 5, 2025
Intramolecular Charge Transfer in Antiaromatic Donor/Acceptor‐Fused s ‐Indacenes
Abstract Herein we report the synthesis and characterization of four donor/acceptor‐fuseds‐indacenes via the late‐stage oxidation of a family of unsymmetrical benzofuran/benzothiophene‐s‐indacene regioisomers. A thorough study of their properties through experimental and computational analysis has revealed the effect of asymmetry on the molecular properties associated with antiaromaticity, as well as a strong correlation between antiaromaticity and intramolecular charge transfer (ICT). The strength of the charge transfer depends on the fusion orientation of the donor and acceptor motifs relative to thes‐indacene core. The two most antiaromatic oxidized isomers exhibit strong evidence of ICT with 30 and 40 nm solvatochromic shifts.
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- Award ID(s):
- 2246964
- PAR ID:
- 10574982
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 64
- Issue:
- 9
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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