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Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
A self-sorting scheme based on tetra-urea calix[4]arenes.
Yuliya Rudzevich1, Valentyn Rudzevich, Fabian Klautzsch
1Abteilung Lehramt Chemie, Fachbereich Chemie, Pharmazie und Geowissenschaften, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55099 Mainz, Germany.
Angewandte Chemie (International Ed. in English)
|April 11, 2009
Summary
Molecular shape and size are crucial for self-sorting. In nonpolar solvents, eleven tetra-urea calix[4]arenes formed only six specific dimers, driven by steric factors and stoichiometry.
Area of Science:
- Supramolecular Chemistry
- Organic Chemistry
- Materials Science
Background:
- Calixarenes are versatile macrocyclic compounds with a well-defined structure.
- Tetra-urea calix[4]arenes are known for their self-assembly properties through hydrogen bonding.
- Controlling the self-assembly of complex mixtures remains a challenge in supramolecular chemistry.
Purpose of the Study:
- To investigate the self-sorting behavior of a mixture of eleven structurally similar tetra-urea calix[4]arenes.
- To determine the factors governing the selective formation of homo- and heterodimers.
- To understand how steric and stoichiometric effects influence self-assembly in solution.
Main Methods:
- Synthesis of eleven tetra-urea calix[4]arenes with varying wide-rim substituents.
- Equimolar mixture preparation in nonpolar solvents.
- Analysis of dimer formation using techniques like NMR spectroscopy and mass spectrometry.
Main Results:
- An equimolar mixture of eleven tetra-urea calix[4]arenes self-sorted into only six distinct homo- and heterodimers.
- The calixarene scaffold and urea units were identical, isolating the influence of wide-rim substituents.
- Self-sorting was driven by the interplay of steric hindrance and stoichiometric ratios.
Conclusions:
- Steric requirements and stoichiometry are dominant factors in the self-sorting of complex calixarene mixtures.
- Precise control over dimer formation is achievable by tuning molecular structure.
- This study provides insights into the design principles for selective self-assembly in supramolecular systems.
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