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Published on: January 17, 2019
Pillar[6]arene-based photoresponsive host-guest complexation.
Guocan Yu1, Chengyou Han, Zibin Zhang
1Department of Chemistry, Zhejiang University, Hangzhou, People's Republic of China.
Journal of the American Chemical Society
|May 1, 2012
Summary
Photoresponsive pillar[6]arenes form host-guest complexes with trans-azobenzene guests, enabling light-controlled aggregation. This supramolecular system offers a novel photo switchable motif for molecular recognition.
Area of Science:
- Supramolecular Chemistry
- Materials Science
- Photochemistry
Background:
- Azobenzene derivatives are widely used in host-guest chemistry for photoresponsive applications.
- Pillararenes, macrocyclic hosts, exhibit size-selective guest binding based on their cavity dimensions.
- Existing host-guest systems, like cyclodextrin/azobenzene, are well-established but have limitations.
Purpose of the Study:
- To investigate the host-guest complexation of azobenzene derivatives with pillar[6]arenes.
- To explore the photoresponsive behavior of pillararene-azobenzene complexes.
- To develop a novel photo switchable supramolecular system for molecular recognition in organic solvents.
Main Methods:
- Synthesis and characterization of pillar[6]arene and pillar[5]arene hosts.
- Host-guest complexation studies using azobenzene-containing guests.
- Photocontrolled aggregation studies using UV and visible light irradiation.
Main Results:
- Pillar[6]arene selectively forms host-guest complexes with the trans isomer of azobenzene, unlike pillar[5]arenes, due to cavity size differences.
- The host-guest complexation between pillar[6]arene and azobenzene undergoes reversible photo-induced aggregation.
- Irradiation with UV and visible light switches the aggregation state between irregular and vesicle-like structures.
Conclusions:
- Pillar[6]arene serves as a photoresponsive host for azobenzene guests, demonstrating size-selective recognition.
- The developed system exhibits reversible photocontrolled aggregation, offering a novel photo switchable motif.
- This pillararene-based system is effective in organic solvents and complements existing recognition motifs.
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