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Updated: Jun 4, 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
Crystal to crystal transformations and polymorphism in anionic hydrogen bonding networks stabilized by crown ether
Dario Braga1, Simone D'Agostino, Fabrizia Grepioni
1Department of Chemistry G. Ciamician, Alma Mater Studiorum University of Bologna, Via Selmi 2, 40126, Bologna, Italy. dario.braga@unibo.it
Dalton Transactions (Cambridge, England : 2003)
|February 24, 2011
Summary
New crystalline molecular salts formed using crown ethers and various ions exhibit crystal transformations. These changes are linked to water loss/uptake and temperature-induced phase transitions, studied via thermal analysis and X-ray diffraction.
Area of Science:
- Supramolecular Chemistry
- Materials Science
- Crystallography
Background:
- Crown ethers, such as 15-crown-5 and 18-crown-6, are known for their ability to complex with various cations.
- Hydrogen-bonded anionic networks are crucial in constructing crystalline materials with tunable properties.
- Molecular salts offer a versatile platform for designing materials with dynamic behaviors.
Purpose of the Study:
- To synthesize and characterize novel crystalline molecular salts using crown ether complexes.
- To investigate the crystal-to-crystal transformations in these complexes.
- To understand the influence of water molecules and temperature on structural changes and phase transitions.
Main Methods:
- Synthesis of crystalline molecular salts via solid-state mixing of reactants.
- Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) to study thermal properties.
- Variable temperature X-ray powder diffraction to analyze structural changes during dehydration and phase transitions.
Main Results:
- Successful construction of crystalline molecular salts incorporating alkali, transition metal, and ammonium cations with crown ethers and diverse anions.
- Observed crystal-to-crystal transformations primarily driven by reversible dehydration/hydration processes.
- Identification of temperature-induced phase transitions accompanied by ionic reorganization within the anionic networks.
Conclusions:
- The studied crown ether-based molecular salts represent a new class of adaptable crystalline materials.
- Their dynamic behavior, including dehydration and phase transitions, can be effectively controlled by external stimuli like temperature and humidity.
- Solid-state synthesis offers a viable route for preparing these complex materials.
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