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Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain
Published on: March 27, 2018
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A Water-Stable Boronate Ester Cage.
Philipp H Kirchner1,2, Louis Schramm1,2, Svetlana Ivanova1,2
1Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany.
Journal of the American Chemical Society
|February 7, 2024
Summary
Stable boronate ester cages were synthesized using sterically hindered building blocks. These novel dynamic covalent materials demonstrate exceptional water and alcohol tolerance, enabling new applications in catalysis and material science.
Area of Science:
- Dynamic Covalent Chemistry
- Supramolecular Chemistry
- Materials Science
Background:
- Reversible condensation of catechols and boronic acids forms boronate esters, a key reaction in dynamic covalent chemistry.
- Hydrolytic instability of traditional boronate esters limits their practical applications.
Purpose of the Study:
- To develop novel boronate ester cages with enhanced stability in aqueous and ambient conditions.
- To explore the potential applications of these stable cages in catalysis and material encapsulation.
Main Methods:
- Synthesis of cubic boronate ester cages (6) using sterically hindered hexahydroxy tribenzotriquinacenes and phenylene diboronic acids with ortho-t-butyl substituents.
- Investigation of the hydrolytic stability and dynamic exchange properties of the synthesized cages under various conditions.
- Demonstration of cage applications through encapsulation/release of dyes and heterogeneous catalysis.
Main Results:
- The synthesized boronate ester cages exhibit significant steric shielding around the boron centers, preventing hydrolysis at neutral pH.
- These cages demonstrate unprecedented stability in the presence of water and alcohols in both solution and solid states.
- Successful application in the encapsulation and controlled release of beta-carotene dyes.
- Demonstrated utility in heterogeneous water oxidation catalysis via ruthenium catalyst encapsulation.
Conclusions:
- Steric shielding is an effective strategy to enhance the hydrolytic stability of boronate ester cages.
- These robust cages represent a new class of dynamic covalent materials with broad applicability under ambient and aqueous conditions.
- The developed materials offer promising avenues for advanced functional materials, drug delivery, and catalysis.
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