Strategies and mechanisms of metal–ligand cooperativity in first-row transition metal complex catalysts

2020 ◽  
Vol 49 (24) ◽  
pp. 8933-8987
Author(s):  
Matthew R. Elsby ◽  
R. Tom Baker
Keyword(s):  
Transition Metal ◽  
Metal Complex ◽  
Homogeneous Catalysis ◽  
Transition Metal Complex ◽  
Bifunctional Catalysts ◽  
Metal Ligand ◽  
Metal Complex Catalysts

The use of metal–ligand cooperation (MLC) by transition metal bifunctional catalysts has emerged at the forefront of homogeneous catalysis science.

Metal-Ligand Cooperative Approaches in Homogeneous Catalysis Using Transition Metal Complex Catalysts of Redox Noninnocent Ligands

2021 ◽  
Author(s):  
Rakesh Mondal ◽  
Amit Kumar Guin ◽  
Gargi Chakraborty ◽  
Nanda D Paul
Keyword(s):  
Transition Metal ◽  
Metal Complex ◽  
Homogeneous Catalysis ◽  
Transition Metal Complex ◽  
Raw Materials ◽  
Value Added ◽  
Catalytic Reactions ◽  
Redox Noninnocent ◽  
Metal Ligand ◽  
Metal Complex Catalysts

Catalysis offers a straightforward route to prepare various value-added molecules starting from readily available raw materials. The catalytic reactions mostly involve multi-electron transformations. Hence, compared to the inexpensive and readily...

Polyolefin structural control using phenoxy-imine ligated group 4 transition metal complex catalysts

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Naoto Matsukawa ◽  
Sei-ichi Ishii ◽  
Rieko Furuyama ◽  
Junji Saito ◽  
Makoto Mitani ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Transition Metal ◽  
Metal Complex ◽  
Structural Control ◽  
Transition Metal Complex ◽  
Control Mechanism ◽  
Central Metal ◽  
Group 4 ◽  
Fi Catalyst ◽  
Metal Complex Catalysts

Abstract This paper describes the structural control of polyolefins achieved by using group 4 transition metal complex catalysts featuring a pair of phenoxy-imine chelate ligands (named FI catalysts). FI catalysts can produce very low to ultrahigh molecular weight polymers. For example, a Zr-FI catalyst bearing a cycloalkyl group on the imine-nitrogen with methylaluminoxane (MAO) activation is capable of selectively forming vinyl-terminated low molecular weight polyethylenes (Mw < 5000) whereas a Zr-FI catalyst with a triethylsilyl group ortho to the phenoxyoxygen can generate ethylene/propylene amorphous copolymers with ultra-high molecular weights (Mw > 10 000 000) when treated with iBu3Al / Ph3CB(C6F5)4. In addition, a Ti-FI catalyst, possessing an o-phenoxytrimethylsilyl group, with MAO can form highly syndiotactic polypropylenes ([rrrr] = 84%, Tm = 140°C) via a chainend control mechanism. Conversely, upon activation with iBu3Al / Ph3CB(C6F5)4, a Hf-FI catalyst with a tert-butyl group ortho to the phenoxy-oxygen is able to produce high molecular weight isotactic polypropylenes ([mm] = 69%, Tm = 124°C, Mw = 412 000) via a site control mechanism. Therefore, FI catalysts have shown the ability to create various polyolefin architectures by simple variation of the central metal, the ligand structure and the co-catalyst.

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