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Abstract We introduce a new boron‐doped cyclophane, the hexabora[16]cyclophaneB6‐FMes, in which six tricoordinate borane moieties alternate with short conjugatedp‐phenylene linkers. Exocyclic 2,4,6‐tris(trifluoromethyl)phenyl (FMes) groups serve not only to further withdraw electron density but at the same time sterically shield the boron atoms, resulting in a macrocycle that is both highly electron‐deficient and stable. The optical and electronic properties are compared with those of related linear oligomers and the electronic structure is further evaluated by computational methods. The studies uncover unique properties ofB6‐FMes, including a low‐lying and extensively delocalized LUMO and a wide HOMO–LUMO gap, which arise from the combination of a cyclic π‐system, strong electronic communication between the closely spaced borons, and the attachment of electron‐deficient pendent groups. The binding of small anions to the electron‐deficient macrocycle and molecular model compounds is investigated and emissive exciplexes are detected in aromatic solvents.
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Electron‐Deficient Conjugated Materials via p–π* Conjugation with Boron: Extending Monomers to Oligomers, Macrocycles, and Polymers
Abstract The extension of conjugated organoboranes from monomeric species to oligomers, macrocycles, and polymers offers access to a plethora of fascinating new materials. The p–π* conjugation between empty orbitals on boron and the conjugated linkers not only affects the electronic structure and optical properties, but also enables mutual interactions between electron‐deficient boron centers. The unique properties of these electron‐deficient π‐conjugated systems are exploited in highly luminescent materials, organic optoelectronic devices, and sensing applications.
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- PAR ID:
- 10236098
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 27
- Issue:
- 9
- ISSN:
- 0947-6539
- Page Range / eLocation ID:
- p. 2973-2986
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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