Ligands Dominate Highly Syndioselective Polymerization of Styrene by Using Constrained-geometry-configuration Rare-earth Metal Precursors

2012 ◽  
Vol 45 (3) ◽  
pp. 1248-1253 ◽  
Author(s):  
Yupeng Pan ◽  
Weifeng Rong ◽  
Zhongbao Jian ◽  
Dongmei Cui
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Constrained Geometry ◽  
Metal Precursors ◽  
Geometry Configuration

scholarly journals Unprecedentedly High Activity and/or High Regio-/Stereoselectivity of Fluorenyl-Based CGC Allyl-Type η3:η1-tert-Butyl(dimethylfluorenylsilyl)amido Ligated Rare Earth Metal Monoalkyl Complexes in Olefin Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 836
Author(s):  
Ge Guo ◽  
Xiaolu Wu ◽  
Xiangqian Yan ◽  
Li Yan ◽  
Xiaofang Li ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Active Species ◽  
Metal Centers ◽  
Tert Butyl ◽  
Alkyl Groups ◽  
Elemental Analyses ◽  
Catalytically Active ◽  
Geometry Configuration

A series of fluorenyl-based constrained-geometry-configuration (CGC) allyl-type rare earth metal monoalkyl complexes bearing the divalent anionic η3:η1-tert-butyl(dimethylfluorenylsilyl)amido (η3:η1-FluSiMe2NtBu) ligand (η3:η1-FluSiMe2NtBu)Ln(CH2SiMe3)(THF)2 (1–3) have been synthesized via the alkane elimination reaction between the FluHSiMe2NHtBu ligand and rare earth metal tri(trimethylsilylmethyl) complexes Ln(CH2SiMe3)3(THF)n. Their structures are characterized by means of NMR spectrum, elemental analyses, and X-ray diffraction. These complexes 1–3 are isostructural and isomorphous, and each of them adopts a distorted-trigonal-bipyramidal configuration containing one η3:η1-FluSiMe2NtBu ligand, one CH2SiMe3 ligand, and two THF molecules. Unlike traditional CGC allyl-type rare earth metal complexes showing no or low activity and regio-/stereoselectivity in styrene or MMA polymerization, these complexes 1–3 exhibit high catalytic activities and/or high regio-/stereoselectivities in the cis-1,4-polymerization of isoprene and myrcene or in the syndiotactic polymerization of styrene under the aid of different activators (borate or borane) and AlR3. The in situ 1H NMR spectra suggest that the exchanges of chelating ligands such as alkyl groups and divalent anionic η3:η1-FluSiMe2NtBu ligands between rare earth metal centers and Al centers result in the formation of a heterobimetallic tetraalkylaluminate complex R2Al(μ-R)2Ln(R)(μ-R)2AlR2, which is activated by activators to form a divalent cationic species [Ln(μ-R)2AlR2]2+ as a catalytically active species in the coordination–insertion polymerization of olefins.

Coordination Polymerization of Renewable 3-Methylenecyclopentene with Rare-Earth-Metal Precursors

2017 ◽  
Vol 129 (16) ◽  
pp. 4631-4635 ◽  
Author(s):  
Bo Liu ◽  
Shihui Li ◽  
Meiyan Wang ◽  
Dongmei Cui
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Coordination Polymerization ◽  
Metal Precursors

Highly syndioselective coordination (co)polymerization of vinyl heteroaromatic monomers using rare-earth-metal complexes

2020 ◽  
Vol 11 (48) ◽  
pp. 7650-7655
Author(s):  
Tiantian Wang ◽  
Chunji Wu ◽  
Dongmei Cui
Keyword(s):  
Molecular Weight ◽  
Rare Earth ◽  
Metal Complexes ◽  
High Activity ◽  
High Molecular Weight ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Coordination Polymerization ◽  
Metal Precursors ◽  
Rare Earth Metal Complexes

This paper demonstrates the coordination polymerization of vinylbenzothiophene and its copolymerization with styrene with high activity and perfect syndioselectivity to give high molecular weight products by using rare-earth-metal precursors.

Highly Isoselective Coordination Polymerization ofortho-Methoxystyrene with β-Diketiminato Rare-Earth-Metal Precursors

2015 ◽  
Vol 54 (17) ◽  
pp. 5205-5209 ◽  
Author(s):  
Dongtao Liu ◽  
Changguang Yao ◽  
Rong Wang ◽  
Meiyan Wang ◽  
Zichuan Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Coordination Polymerization ◽  
Metal Precursors

Highly Isoselective Coordination Polymerization ofortho-Methoxystyrene with β-Diketiminato Rare-Earth-Metal Precursors

2015 ◽  
Vol 127 (17) ◽  
pp. 5294-5298 ◽  
Author(s):  
Dongtao Liu ◽  
Changguang Yao ◽  
Rong Wang ◽  
Meiyan Wang ◽  
Zichuan Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Coordination Polymerization ◽  
Metal Precursors
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