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Updated: Jul 9, 2025
12:19
Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
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Coplanar binuclear group 4 post-metallocene complexes supported by chelating μ-(σ2-aryl) ligands: characterisation
Yufang Li1, Qian Liu1, Junhui Bao1
1Department of Chemistry and Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. mcwchan@cityu.edu.hk.
Dalton Transactions (Cambridge, England : 2003)
|December 5, 2023
Summary
New bimetallic catalysts with locked-in "syn" orientation show enhanced efficiency and polymer properties. These rigid assemblies enable predetermined metal-metal distances for cooperative reactivity in polymerization.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Polymer Science
Background:
- Previously developed M-[O,N,C] [pyridine-2-phenolate-6-(σ-aryl)] catalyst systems.
- Need for rigid, coplanar bimetallic assemblies with controlled metal-metal distances and substrate access.
Purpose of the Study:
- Expand catalyst system into rigid, coplanar bimetallic assemblies.
- Investigate cooperative reactivity and catalytic performance.
Main Methods:
- Regioselective synthesis of binuclear complexes.
- Characterization using multinuclear NMR spectroscopy and X-ray crystallography.
- Ethylene and ethylene/1-octene polymerization reactions.
Main Results:
- Synthesized and characterized six syn-type bimetallic derivatives of Ti, Zr, and Hf with metal-metal separations of 6.3-6.7 Å.
- Syn-Ti2 catalysts exhibited superior efficiencies and higher molecular weight polymers compared to anti and mono-Ti congeners.
- Demonstrated favorable enchainment interactions and cooperative reactivity.
Conclusions:
- Rigid, syn-oriented bimetallic catalysts offer advantages in polymerization.
- Predetermined metal-metal distances and locked-in substrate access facilitate cooperative effects.
- Potential for developing highly efficient polymerization catalysts.
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