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Updated: Jul 2, 2026
06:35
Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
TABF as a Double Proton Sponge: Steric Preorganization versus Antiaromatic Destabilization.
Julien F Rowen1, Yining Liu2, Maurice Niehoff1
1Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Bochum 47780, Germany.
The Journal of Organic Chemistry
|July 1, 2026
Summary
Researchers synthesized a new proton sponge, 1,1
Area of Science:
- Organic Chemistry
- Supramolecular Chemistry
Background:
- Proton sponges are organic molecules with high basicity.
- Their basicity depends on molecular structure.
- 1,8-bis(dimethylamino)naphthalene (DMAN) is a common proton sponge.
Purpose of the Study:
- To synthesize a novel proton sponge scaffold, 1,1',8,8'-tetraazabifluorenylidene (TABF).
- To investigate the acid-base properties and structural characteristics of TABF.
- To understand the relationship between molecular architecture and basicity in proton sponges.
Main Methods:
- Synthesis of the TABF scaffold.
- Single-crystal X-ray diffraction to determine molecular structures.
- UV-vis spectrophotometric titrations in acetonitrile to determine acid-base properties.
Main Results:
- The synthesis of TABF was successful.
- X-ray diffraction confirmed the structures of the neutral base and the dication.
- Spectrophotometric titrations yielded pKaH,2 = 15.0-15.6 and pKaH,1 ≈ 18.
- TABF exhibits lower basicity than DMAN.
Conclusions:
- TABF is a novel proton sponge with tunable basicity.
- The reduced basicity is due to antiaromatic destabilization in protonated forms.
- Electronic structure and charge distribution are crucial for designing organic superbases.
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