4.7 Article

Enhancing isoprene polymerization with high activity and adjustable monomer enchainment using cyclooctyl-fused iminopyridine iron precatalysts

Related references

Note: Only part of the references are listed.
Article Polymer Science

Synthesis, Structure, and Properties of Poly(isoprene)s of Different Constitutions and Configurations from Catalysts Based on Complexes of Nd, Co, and Fe

Miriam Scoti et al.

Summary: Poly(isoprene)s with various molecular structures and mechanical properties have been synthesized using different catalysts. The synthesized polymers include cis-1,4 structures, 3,4 syndiotactic structures, regular alternating cis-1,4-alt-3,4 structures, and structures with alternating cis-1,4-alt-3,4 but with different lengths of cis-1,4 sequences. The structure and properties of these polymers, including their crystallization behavior and glass transition temperatures, have been studied.

MACROMOLECULES (2023)

Article Polymer Science

Enhancing the thermal stability of α-Diimine Ni(II) catalysts for ethylene polymerization via symmetrical axial shielding strategy

Luyao Wang et al.

Summary: A series of symmetrical alpha-diimine-nickel complexes bearing functionalized 2,6-dibenzhydryl-4-t-butylphenyl N-aryl were synthesized and compared with their unsymmetrical analogues for ethylene polymerization. The symmetrical catalysts exhibited high activities and produced high molecular weight branched polyethylene at all reaction temperatures, while the unsymmetrical catalysts showed low activities and became completely inactive at 100 degrees C. The enhanced thermal stability of the nickel complexes was attributed to the 7C-7C interactions between the acenaphthylene and phenyl of benzhydryl group.

EUROPEAN POLYMER JOURNAL (2023)

Article Chemistry, Physical

Structurally Rigid (8-(Arylimino)-5,6,7-trihydroquinolin-2-yl)-methyl Acetate Cobalt Complex Catalysts for Isoprene Polymerization with High Activity and cis-1,4 Selectivity

Nighat Yousuf et al.

Summary: A series of cobalt complexes with a (8-(arylimino)-5,6,7-trihydroquinolin-2-yl)methyl acetate ligand framework were synthesized using a one-pot method. The complexes were characterized by FT-IR spectrum and elemental analysis, and the molecular structure of Co1 and Co5 was determined by X-ray diffraction analysis. Co1 showed the highest catalytic activity with complete monomer conversion, producing polyisoprene with high molecular weight. The cis-1,4 configuration was preferred in all complexes, while the 3,4 monomer insertion units constituted a certain percentage of the polymer structure. Extensive investigations were conducted to understand the effect of reaction parameters and ligand properties on the catalytic activities and microstructural characteristics of the resulting polymer.

CATALYSTS (2023)

Article Chemistry, Inorganic & Nuclear

Polyethylene Waxes with Short Chain Branching via Steric and Electronic Tuning of an 8-(Arylimino)-5,6,7-trihydroquinoline-nickel Catalyst

Shu Jiang et al.

Summary: This study reports ten nickel(II) halide complexes incorporating a sterically encumbered 5,6,7-trihydroquinoline ligand. It was found that catalysts with alkyl substituents displayed higher activity and formed high-molecular weight polymers with narrower dispersity compared to those with halide substituents in ethylene polymerization reactions.

ORGANOMETALLICS (2022)

Article Chemistry, Applied

Pyridine-oxazoline ligated iron complexes: Synthesis, characterization, and catalytic activity for isoprene polymerization

Mengmeng Zhao et al.

Summary: A series of iron(II) dichloride complexes (Fe1-Fe3) and iron(II) acetylacetonate complex (Fe4) bearing different oxazoline ligands were synthesized and showed excellent activity towards isoprene polymerization. The ligand environment and counter anion on iron center displayed significant effects on polymerization activity and selectivity. The possible polymerization mechanism was proposed.

APPLIED ORGANOMETALLIC CHEMISTRY (2022)

Article Chemistry, Multidisciplinary

Making Polyisoprene Self-Healable through Microstructure Regulation by Rare-Earth Catalysts

Haobing Wang et al.

Summary: The synthesis of self-healing polymers from simple commodity dienes, such as isoprene, using catalyst-controlled polymerization has shown to produce excellent self-healing elastomers. The self-healability is attributed to nanoscale heterogeneities formed by microphase separation of hard 3,4-segments from a flexible cis-1,4-segment matrix.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2022)

Article Polymer Science

Synthesis, Characterization and Catalytic Property Studies for Isoprene Polymerization of Iron Complexes Bearing Unionized Pyridine-Oxime Ligands

Mengmeng Zhao et al.

Summary: Iron complexes with different pyridine-oxime ligands were synthesized and characterized. The crystal structure of one complex was determined, demonstrating the coordination mode of the pyridine-oxime ligands. The complexes showed high catalytic activity in the polymerization of isoprene.

POLYMERS (2022)

Review Chemistry, Inorganic & Nuclear

Structural evolution of iminopyridine support for nickel/palladium catalysts in ethylene (oligo)polymerization

Qaiser Mahmood et al.

Summary: This review summarizes the latest research progress on mononuclear iminopyridine-nickel and -palladium catalysts in ethylene (oligo)polymerization, focusing on the correlation between catalyst structure and polymer properties, and comparing the structural variations in binuclear iminopyridine-nickel catalysts. The research findings are of great significance in the development of new efficient catalyst designs.

DALTON TRANSACTIONS (2022)

Article Polymer Science

Highly Stereoregular 1,3-Butadiene and Isoprene Polymers through Monoalkyl-N-Aryl-Substituted Iminopyridine Iron Complex-Based Catalysts: Synthesis and Characterization

Giovanni Ricci et al.

Summary: In this study, novel monoalkyl-N-aryl-substituted iminopyridine iron chloride complexes were synthesized and characterized for the polymerization of 1,3-butadiene and isoprene. The coordination around the iron center was found to be distorted tetrahedral, which is rare for FeCl2 adducts with bidentate nitrogen ligands. The resulting poly(isoprene)s exhibited predominantly cis-1,4/3,4 alternating structure with short cis-1,4 sequences of three or five units, depending on the nature of the ligand on the iron atom.

MACROMOLECULES (2021)

Article Materials Science, Characterization & Testing

Ligand-regulated polymerization of conjugated dienes catalyzed by confined iminopyridine iron complexes with high activity and thermal stability

Guangqian Zhu et al.

Summary: Confined iminopyridine iron complexes with skeleton of 8-(arylimino)-5,6,7-trihydroquinolyl were synthesized and characterized, serving as highly efficient pre-catalysts for conjugated dienes polymerization. Adjusting substituents of ligand framework allowed for control of stereoselectivity, achieving high activity and molecular weight in polymerization reactions. The Fe1/MAO catalytic system showed excellent thermostability and high activity in polymerizing bio-based monomers, delivering green rubber with high molecular weights.

POLYMER TESTING (2021)

Review Chemistry, Inorganic & Nuclear

Multinuclear late transition metal catalysts for olefin polymerization

Mostafa Khoshsefat et al.

Summary: The aim of designing multinuclear catalysts for olefin polymerization is to control the catalyst behavior and final polymer properties, with the length and nature of the linker playing a key role in metal center adjacency and cooperative interactions. Late transition metal catalysts are attractive due to their structure and behavior, leading to increased interest in multinuclear catalysts.

COORDINATION CHEMISTRY REVIEWS (2021)

Article Chemistry, Inorganic & Nuclear

Ethylene oligomerization with 2-hydroxymethyl-5,6,7-trihydroquinolinyl-8-ylideneamine-Ni(II) chlorides

Lei Xu et al.

Summary: These Ni complexes showed high activity in ethylene oligomerization when activated with MMAO or Et2AlCl, with activities reaching 2.23 x 10(6) g.mol(-1) (Ni) h(-1) and 9.11 x 10(5) g.mol(-1) (Ni) h(-1) respectively. High selectivity exceeding 99% for oz-C4 was observed in the Ni/Et2AlCl system.

JOURNAL OF ORGANOMETALLIC CHEMISTRY (2021)

Review Polymer Science

Recent advancements in α-diimine-nickel and -palladium catalysts for ethylene polymerization

Muhammad Qasim et al.

Summary: Metal catalysts play an important role in controlling the properties of polymers, with a focus on structure-activity relationships. By introducing electronic and steric substituents into the catalysts, researchers can modulate catalyst activity, chain walking mechanism, and thermal stability. Axial steric substitution is crucial for obtaining polymers with specific properties, especially in the case of producing highly branched polyethylene for various industrial applications.

EUROPEAN POLYMER JOURNAL (2021)

Article Polymer Science

Dienes Polymerization: Where We Are and What Lies Ahead

Giovanni Ricci et al.

Summary: Research activity in the stereospecific polymerization of conjugated dienes has recently focused on the use of organometallic catalysts with well-defined structures and various types of ligands, which can strongly influence polymerization regio- and stereoselectivity, molecular weights, and living characteristics of the catalysts. Recent results in this field are highlighted in this Perspective, along with discussions on possible future developments.

MACROMOLECULES (2021)

Article Chemistry, Inorganic & Nuclear

Enhancing Thermal Stability in Aminopyridine Iron(II)-Catalyzed Polymerization of Conjugated Dienes

Chuyang Jing et al.

ORGANOMETALLICS (2020)

Article Polymer Science

Highly active and thermo-stable iminopyridyl vanadium oxychloride catalyzed isoprene polymerization

Mengmeng Zhao et al.

JOURNAL OF POLYMER SCIENCE (2020)

Article Chemistry, Multidisciplinary

An unsymmetrical binuclear iminopyridine-iron complex and its catalytic isoprene polymerization

Liang Wang et al.

CHEMICAL COMMUNICATIONS (2020)

Article Chemistry, Applied

Controlled isoprene polymerization mediated by iminopyridine-iron (II) acetylacetonate pre-catalysts

Mengmeng Zhao et al.

APPLIED ORGANOMETALLIC CHEMISTRY (2019)

Review Chemistry, Inorganic & Nuclear

Discrete iron-based complexes: Applications in homogeneous coordination-insertion polymerization catalysis

Yohan Champouret et al.

COORDINATION CHEMISTRY REVIEWS (2019)

Article Biochemistry & Molecular Biology

Highly Active Iminopyridyl Iron-Based Catalysts for the Polymerization of Isoprene

Obaid H. Hashmi et al.

MOLECULES (2019)

Article Polymer Science

Iminoimidazole-based Co(II) and Fe(II) complexes: Syntheses, characterization, and catalytic behaviors for isoprene polymerization

Xianhui Zhang et al.

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY (2019)

Article Chemistry, Inorganic & Nuclear

Ring-tension adjusted ethylene polymerization by aryliminocycloheptapyridyl nickel complexes

Fang Huang et al.

DALTON TRANSACTIONS (2015)

Article Chemistry, Multidisciplinary

The behaviour of β-triketimine cobalt complexes in the polymerization of isoprene

Mohammed N. Alnajrani et al.

RSC ADVANCES (2015)

Article Chemistry, Inorganic & Nuclear

(Phenoxyimidazolyl-salicylaldimine)iron complexes: synthesis, properties and iron catalysed ethylene reactions

Margaret Yankey et al.

DALTON TRANSACTIONS (2014)

Article Chemistry, Multidisciplinary

Iron-Catalyzed Polymerization of Isoprene and Other 1,3-Dienes

Jean Raynaud et al.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2012)

Review Polymer Science

Bio-inspired cationic polymerization of isoprene and analogues: state-of-the-art

Samira Ouardad et al.

POLYMER INTERNATIONAL (2012)

Review Chemistry, Inorganic & Nuclear

Well-defined transition metal complexes with phosphorus and nitrogen ligands for 1,3-dienes polymerization

Giovanni Ricci et al.

COORDINATION CHEMISTRY REVIEWS (2010)

Article Polymer Science

cis-1,4-alt-3,4 Polyisoprene: Synthesis and Characterization

Giovanni Ricci et al.

MACROMOLECULES (2009)