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Abstract A sterically strained 32π‐electron antiaromatic bis‐BODIPY macrocycle in which two BODIPY fragments are linked byp‐divinylbenzene groups was prepared and characterized. Unlike regular BODIPYs, the fluorescence in this macrocycle is quenched. The broad signals in the NMR spectra of the macrocycle were explained by the vibronic freedom of thep‐divinylbenzene fragments. The possible diradicaloid nature of the macrocycle was excluded on the basis of variable‐temperature EPR spectra in solution and in solid state, which is indicative of its closed‐shell quinoidal structure. Themeso‐C−H bond in the macrocycle and its precursor BODIPY dialdehyde3forms a weak hydrogen bond with THF and is susceptible for the nucleophilic attack by organic amines and cyanide anion. The reaction products of such a nucleophilic attack havemeso‐sp3carbon atoms and were characterized by NMR, mass spectrometry and, in one case, X‐ray crystallography. Unlike the initial bis‐BODIPY macrocycle, the adducts have strong fluorescence in the 400 nm region. The electronic structure and spectroscopic properties of new chromophores were probed by density functional theory (DFT) and time‐dependent DFT (TDDFT) calculations and correlate well with the experimental data.
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meso -Alkylidenyl dibenzihexaphyrins: synthesis and protonation studies
The synthesis and characterization of the alkylidenyl-dibenzihexaphyrins bearing four indanedionyl groups at the meso -positions linked via four meso -exocyclic double bonds is reported. Treatment with trifluoroacetic acid at 50 °C leads to C(α)-protonation of the two indanedionyl groups resulting increased macrocyclic conjugation with dramatic red shifted absorption spectra.
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- Award ID(s):
- 1807152
- PAR ID:
- 10170774
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 55
- Issue:
- 65
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 9693 to 9696
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/c9cc04607k
