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Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Cationic borohydrido-neodymium complex: synthesis, characterization and its application as an efficient pre-catalyst
Marc Visseaux1, Michael Mainil, Michael Terrier
1Unité de Catalyse et de Chinmie du Solide (UCCS, UMR 8181 CNRS), ENSCL, Bât. C7, Cité Scientifique, B.P 90108, 59652, Villeneuve d'Ascq cedex, France. marc.visseaux@ensc-lille.fr
Dalton Transactions (Cambridge, England : 2003)
|November 26, 2008
Summary
A novel cationic lanthanide complex demonstrates high activity in isoprene polymerization. While a related ternary system shows lower activity, it offers superior cis-selectivity and enhanced control over polymer properties.
Area of Science:
- Organometallic Chemistry
- Polymer Science
- Catalysis
Background:
- Lanthanide complexes are explored as catalysts for olefin polymerization.
- Borohydrido ligands and bulky counterions can influence catalytic activity and selectivity.
- Controlling polymer microstructure is crucial for material properties.
Purpose of the Study:
- To synthesize and characterize a cationic borohydrido lanthanide complex.
- To evaluate the catalytic performance of this complex in isoprene polymerization.
- To compare its efficacy with a related in situ generated ternary system.
Main Methods:
- Synthesis of [Nd(BH4)2(THF)5][B(C6F5)4] from Nd(BH4)3(THF)3 and [HNMe2Ph][B(C6F5)4].
- Activation of the complex with aluminum alkyl (Al(i-Bu)3) for polymerization.
- Preparation and evaluation of an in situ ternary catalytic system.
Main Results:
- The cationic complex exhibits high activity in isoprene polymerization when activated with Al(i-Bu)3.
- The in situ ternary system, though less active, provides higher cis-selectivity.
- The ternary system also demonstrates improved control over macromolecular characteristics.
Conclusions:
- Cationic lanthanide borohydride complexes can be effective catalysts for isoprene polymerization.
- Ternary catalytic systems offer tunable selectivity and control over polymer architecture.
- The choice of catalyst system impacts both activity and the resulting polymer microstructure.
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