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Updated: May 11, 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
Threaded structures based on the benzo-21-crown-7/secondary ammonium salt recognition motif using esters as end
Bo Zheng1, Mingming Zhang, Xuzhou Yan
1Center for Chemistry of High-Performance and Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
Organic & Biomolecular Chemistry
|May 10, 2013
Summary
Researchers created novel threaded molecular structures using benzo-21-crown-7 and ammonium salts. Tailoring ester end groups, particularly with isopropyl groups, enabled the construction of stable, mechanically interlocked rotaxanes.
Area of Science:
- Supramolecular Chemistry
- Organic Synthesis
- Materials Science
Background:
- Crown ethers and ammonium salts are known for their host-guest complexation capabilities.
- Threaded structures represent a class of mechanically interlocked molecules with unique properties.
- Controlling molecular architecture is key to developing advanced functional materials.
Purpose of the Study:
- To synthesize and characterize novel threaded structures using a benzo-21-crown-7/secondary ammonium salt recognition motif.
- To investigate the influence of different ester end groups on the formation and stability of these threaded structures.
- To differentiate between rotaxane-like entities and true [2]rotaxanes based on structural features.
Main Methods:
- Synthesis of various compounds with different ester end groups.
- Structural confirmation using Nuclear Magnetic Resonance (NMR) spectroscopy ((1)H and (13)C) and mass spectrometry.
- Solid-state structural analysis via single crystal X-ray diffraction.
- Distinguishing molecular architectures using NMR experiments.
Main Results:
- Successfully constructed various threaded structures by varying ester end groups.
- Confirmed the threaded nature of all synthesized compounds in the solid state via X-ray analysis.
- Identified that linear n-alkyl end groups yield rotaxane-like entities.
- Demonstrated that increasing the length of the ester alkyl chain enhances the stability of the threaded structures.
- Achieved the construction of a mechanically interlocked rotaxane when using an isopropyl group as the tail.
Conclusions:
- The benzo-21-crown-7/secondary ammonium salt system effectively forms threaded structures.
- Ester end group modification provides a versatile strategy for controlling the architecture and stability of rotaxanes.
- Isopropyl-capped structures represent a significant step towards robust mechanically interlocked molecular architectures.
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