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Abstract The functionalization of polycyclic aromatic hydrocarbons (PAHs) via B←N Lewis pair formation offers an opportunity to judiciously fine‐tune the structural features and optoelectronic properties, to suit the demands of applications in organic electronic devices, bioimaging, and as sensitizers for singlet oxygen generation. We demonstrate that the N‐directed electrophilic borylation of 2,6‐di(pyrid‐2‐yl)anthracene offers access to linearly extended acene derivativesPy‐BR(R=Et, Ph, C6F5). In comparison to indeno‐fused 9,10‐diphenylanthracene, the formal “BN for CC” replacement inPy‐BRselectively lowers the LUMO, resulting in a much reduced HOMO–LUMO gap. An even more extended conjugated system with seven six‐membered rings in a row (Qu‐BEt) is obtained by borylation of 2,6‐di(quinolin‐8‐yl)anthracene. FluorinatedPy‐BPfshows particularly advantageous properties, including relatively lower‐lying HOMO and LUMO levels, strong yellow‐green fluorescence, and effective singlet oxygen sensitization, while resisting self‐sensitized conversion to its endoperoxide.
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Optomagneto control of singlet fission charge multiplication dynamics in single organic semiconductor crystals
Over a 0-7 T range, transient absorption microscopy on anthradithiophene organic crystals shows that singlet to triplet pair state conversion is anticorrelated with fluorescence yield. This shows how the dominant singlet fission charge multiplication pathway can be switched-off with increasing B-field or by changing the molecular packing motifs.
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- Award ID(s):
- 1920368
- PAR ID:
- 10478633
- Publisher / Repository:
- Optica Publishing Group
- Date Published:
- ISBN:
- 978-1-957171-25-8
- Page Range / eLocation ID:
- FF2G.4
- Format(s):
- Medium: X
- Location:
- San Jose, CA
- Sponsoring Org:
- National Science Foundation
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