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Abstract We herein describe a new design principle to achieve B/N‐doped cyclophane where an electron‐donor block of three triarylamines (Ar3N) and an acceptor block of three triarylboranes (Ar3B) are spatially separated on opposite sides of the π‐extended ring system. DFT computations revealed the distinct electronic structure of theblock‐type macrocycleMC‐b‐B3N3with a greatly enhanced dipole moment and reduced HOMO–LUMO energy gap in comparison to its analogue with alternating B and N sites,MC‐alt‐B3N3. The unique arrangement of borane acceptor Ar3B and amine donor Ar3N components inMC‐b‐B3N3induces exceptionally strong intramolecular charge transfer in the excited state, which is reflected in a largely red‐shifted luminescence at 612 nm in solution. The respective linear open‐chain oligomerL‐b‐B3N3was also synthesized for comparison. Our new approach to donor–acceptor macrocycles offers important fundamental insights and opens up a new avenue to unique optoelectronic materials.
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This content will become publicly available on December 10, 2026
B‐N Fused Anthracene as Functional Linker for π‐Extended Viologens: Near‐IR Emission and Electrochromism
Abstract As prototypical organic electrochromic materials viologens have been extensively studied in display technologies, smart materials, and energy storage applications. Their properties can be fine‐tuned by introducing different substituents on the pyridine rings, fusion with heteroatoms, or insertion of π–conjugated linkers. In this article we study the effect of B‐N fused dipyridylanthracene (BDPA) as a novel linker unit in viologens on the electronic structure, optical properties, and electrochromic characteristics. Quaternization of pyridyl‐functionalized BDPA (1Py) by N‐methylation or complexation with B(C6F5)3as a powerful Lewis acid gives rise to two fundamentally different π‐extended viologens, dicationic [1Py‐Me](PF6)2, and the neutral complex1Py‐BCF. We investigate the effect of these different quaternization methods on the LUMO energy, band gaps, absorption and emission, and the self‐sensitized reactivity toward oxygen. We also demonstrate facile electrochemical reduction to singly and multiply reduced species. Spectroelectrochemical and computational studies reveal formation of strongly colored doubly reduced species with a closed shell electronic configuration and prominent quinoidal delocalization. The corresponding radical anions give rise to absorptions in the near‐IR. A prototype electrochromic device with1Py‐BCFas the redox‐active material is also presented.
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- PAR ID:
- 10659287
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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