Dinuclear Group 4 Metal Complexes Bearing Anthracene-Bridged Bifunctional Amido-Ether Ligands: Remarkable Metal Effect and Cooperativity toward Ethylene/1-Octene Copolymerization.

Two types of bifunctional amido-ether ligands (syn-L and anti-L) with the rigid anthracene skeleton were designed to support dinuclear group 4 metal complexes. All organic ligands and organometallic complexes (syn-M2 and anti-M2; M = Hf, Zr, and Ti) were fully characterized by 1H and 13C NMR spectroscopies and elemental analyses. The anti-Hf2 complex showed two confirmations at room temperature with C2-symmetry or S2-symmetry that can inter-exchange, as indicated by VT NMR, while only a C2-symmetric isomer was observed for syn-Hf2 complex at room temperature. However, for Zr and Ti analogues, both syn and anti complexes exhibited only one conformation at room temperature. The molecular structures of complexes syn-Hf2, anti-Hf2, and syn-Ti2 in the solid state were further determined by single-crystal X-ray diffraction, revealing the distances between two metal centers in syn-M2 from 7.138 Å (syn-Ti2) to 7.321 Å (syn-Hf2) but a much farther separation in anti-M2 (8.807 Å in C2-symmetric anti-Hf2). The mononuclear complex (2-CH3O-C6H4-N-C14H9)Zr(NMe2)3 (mono-Zr1) was also prepared for control experiments. In the presence of alkyl aluminum (AlEt3) as the alkylating agent and trityl borate ([Ph3C][B(C6F5)4]) as the co-catalyst, all metal complexes were tested for copolymerization of ethylene with 1-octene at high temperature (130 °C). The preliminary polymerization results revealed that the activity was highly dependent upon the nature of metal centers, and syn-Zr2 showed the highest activity of 9600 kg(PE)·mol-1 (Zr)·h-1, which was about 17- and 2.2-fold higher than those of syn-Hf2 and syn-Ti2, respectively. Benefitting from both steric proximity and electronical interaction of two metal centers, syn-Zr2 exhibited significant cooperativity in comparison to anti-Zr2 and mono-Zr1, with regard to activity and molecular weight and 1-octene incorporation of resultant copolymers.

[1]  Jiliang Tian,et al.  Titanium Complexes Bearing NNO‐Tridentate Ligands: Highly Active Olefin Polymerization Catalysts with Great Control on Molecular Weight and Distribution , 2022, Chinese Journal of Chemistry.

[2]  Xiaohui Kang,et al.  Suppression of Chain Transfer at High Temperature in Catalytic Olefin Polymerization. , 2022, Angewandte Chemie.

[3]  Zhibo Li,et al.  Controlling Polyethylene Molecular Weights and Distributions Using Chromium Complexes Supported by SNN-Tridentate Ligands , 2022, Macromolecules.

[4]  Changle Chen,et al.  An Ionic Cluster Strategy for Performance Improvements and Product Morphology Control in Metal-Catalyzed Olefin-Polar Monomer Copolymerization. , 2022, Journal of the American Chemical Society.

[5]  Jiliang Tian,et al.  Chromium Complexes Supported by NNO-Tridentate Ligands: An Unprecedent Activity with the Low Requirement of MAO , 2022, Polymer Chemistry.

[6]  Tiantian Wang,et al.  Direct Synthesis of Functional Thermoplastic Elastomer with Excellent Mechanical Properties by Scandium-Catalyzed Copolymerization of Ethylene and Fluorostyrenes. , 2021, Angewandte Chemie.

[7]  T. Agapie,et al.  Copolymerization of Ethylene and Long-Chain Functional α-Olefins by Dinuclear Zirconium Catalysts , 2021 .

[8]  Changle Chen,et al.  Hydrogen-Bonding-Induced Heterogenization of Nickel and Palladium Catalysts for Copolymerization of Ethylene with Polar Monomers. , 2021, Angewandte Chemie.

[9]  Zhibo Li,et al.  Development of Group 4 Metal Complexes Bearing Fused-Ring Amido-Trihydroquinoline Ligands with Improved High-Temperature Catalytic Performance toward Olefin (Co)polymerization , 2021 .

[10]  Zhibo Li,et al.  Cooperativity in Highly Active Ethylene Dimerization by Dinuclear Nickel Complexes Bearing a Bifunctional PN Ligand , 2020, Organometallics.

[11]  Zhibo Li,et al.  Synthesis of Anthracene-Bridged Dinuclear Phenoxyiminato Organotitanium Catalysts with Enhanced Activity, Thermal Stability, and Comonomer Incorporation Ability toward Ethylene (Co)polymerization , 2020 .

[12]  Wen‐Hua Sun,et al.  Recent advancements in N-ligated group 4 molecular catalysts for the (co)polymerization of ethylene , 2020 .

[13]  Christopher P. B. Nicholson,et al.  Variable Temperature NMR Experiment Studying Restricted Bond Rotation , 2020 .

[14]  Guangfu Liao,et al.  Thermally robust α-diimine nickel and palladium catalysts with constrained space for ethylene (co)polymerizations , 2020 .

[15]  T. Marks,et al.  Early Transition Metal Catalysis for Olefin-Polar Monomer Copolymerization. , 2020, Angewandte Chemie.

[16]  Zhe Ma,et al.  Functional Isotactic Polypropylenes via Efficient Direct Copolymerizations of Propylene with Various Amino-Functionalized α-Olefins , 2019 .

[17]  Matthew D. Christianson,et al.  Unexpected Precatalyst σ-Ligand Effects in Phenoxyimine Zr-Catalyzed Ethylene/1-Octene Copolymerizations. , 2019, Journal of the American Chemical Society.

[18]  Wen‐Hua Sun,et al.  Recent advances in homogeneous chromium catalyst design for ethylene tri-, tetra-, oligo- and polymerization , 2019, Coordination Chemistry Reviews.

[19]  Xiangyang Song,et al.  Optically Transparent Functional Polyolefin Elastomer with Excellent Mechanical and Thermal Properties. , 2019, ACS macro letters.

[20]  Wen‐Hua Sun,et al.  Developments in compartmentalized bimetallic transition metal ethylene polymerization catalysts , 2018, Coordination Chemistry Reviews.

[21]  T. Marks,et al.  How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst , 2018, Organometallics.

[22]  Changle Chen.  Designing catalysts for olefin polymerization and copolymerization: beyond electronic and steric tuning , 2018, Nature Reviews Chemistry.

[23]  T. Marks,et al.  Catalyst Nuclearity Effects on Stereo- and Regioinduction in Pyridylamidohafnium-Catalyzed Propylene and 1-Octene Polymerizations , 2018 .

[24]  Zhibo Li,et al.  Bimetallic aluminum complexes supported by bis(salicylaldimine) ligand: Synthesis, characterization and ring-opening polymerization of lactide , 2018, Chinese Journal of Polymer Science.

[25]  T. Marks,et al.  Distinctive Stereochemically Linked Cooperative Effects in Bimetallic Titanium Olefin Polymerization Catalysts , 2017 .

[26]  Wen‐Hua Sun,et al.  Recent advances in Ni-mediated ethylene chain growth: N imine -donor ligand effects on catalytic activity, thermal stability and oligo-/polymer structure , 2017 .

[27]  T. Agapie,et al.  Olefin Polymerization by Dinuclear Zirconium Catalysts Based on Rigid Teraryl Frameworks: Effects on Tacticity and Copolymerization Behavior , 2017 .

[28]  Guodong Liang,et al.  Enhancing Thermal Stability and Living Fashion in α-Diimine–Nickel-Catalyzed (Co)polymerization of Ethylene and Polar Monomer by Increasing the Steric Bulk of Ligand Backbone , 2017 .

[29]  Anne M. LaPointe,et al.  Combining polyethylene and polypropylene: Enhanced performance with PE/iPP multiblock polymers , 2017, Science.

[30]  Yue-sheng Li,et al.  Neutral Nickel Catalysts for Olefin Homo- and Copolymerization: Relationships between Catalyst Structures and Catalytic Properties. , 2015, Chemical reviews.

[31]  T. Marks,et al.  Pyridylamido Bi-Hafnium Olefin Polymerization Catalysis: Conformationally Supported Hf···Hf Enchainment Cooperativity , 2015 .

[32]  R. Figueroa,et al.  Development of group IV molecular catalysts for high temperature ethylene-α-olefin copolymerization reactions. , 2015, Accounts of chemical research.

[33]  Jianbo Hou,et al.  Development of Improved Amidoquinoline Polyolefin Catalysts with Ultrahigh Molecular Weight Capacity , 2015 .

[34]  G. Sheldrick.  Crystal structure refinement with SHELXL , 2015, Acta crystallographica. Section C, Structural chemistry.

[35]  S. Mecking,et al.  Post-metallocenes in the industrial production of polyolefins. , 2014, Angewandte Chemie.

[36]  T. Marks,et al.  Multinuclear group 4 catalysis: olefin polymerization pathways modified by strong metal-metal cooperative effects. , 2014, Accounts of chemical research.

[37]  T. Marks,et al.  Very large cooperative effects in heterobimetallic titanium-chromium catalysts for ethylene polymerization/copolymerization. , 2014, Journal of the American Chemical Society.

[38]  T. Agapie,et al.  Bimetallic Zirconium Amine Bis(phenolate) Polymerization Catalysts: Enhanced Activity and Tacticity Control for Polyolefin Synthesis , 2014, Organometallics.

[39]  T. Marks,et al.  Synthesis, characterization, and heterobimetallic cooperation in a titanium-chromium catalyst for highly branched polyethylenes. , 2013, Journal of the American Chemical Society.

[40]  Ayusman Sen,et al.  Ortho-phosphinobenzenesulfonate: a superb ligand for palladium-catalyzed coordination-insertion copolymerization of polar vinyl monomers. , 2013, Accounts of chemical research.

[41]  Wonseok Hwang,et al.  Dinuclear bis-propagators for the stereoselective living coordinative chain transfer polymerization of propene. , 2013, Journal of the American Chemical Society.

[42]  C. Pellecchia,et al.  New Titanium and Hafnium Complexes Bearing [−NNN–] Pyrrolylpyridylamido Ligands as Olefin Polymerization Catalysts , 2012 .

[43]  D. Pappalardo,et al.  New (Anilidomethyl)pyridine Titanium(IV) and Zirconium(IV) Catalyst Precursors for the Highly Chemo- and Stereoselective cis-1,4-Polymerization of 1,3-Butadiene , 2011 .

[44]  T. Marks,et al.  Multinuclear olefin polymerization catalysts. , 2011, Chemical reviews.

[45]  H. Terao,et al.  FI catalysts for olefin polymerization--a comprehensive treatment. , 2011, Chemical reviews.

[46]  M. Bochmann.  The Chemistry of Catalyst Activation: The Case of Group 4 Polymerization Catalysts† , 2010 .

[47]  C. Pellecchia,et al.  Group 4 bis(chelate) metal complexes of monoanionic bidentate [E,O-] ligands (E = O, S): synthesis and application as alpha-olefin polymerization catalysts. , 2009, Dalton transactions.

[48]  V. Busico.  Metal-catalysed olefin polymerisation into the new millennium: a perspective outlook. , 2009, Dalton transactions.

[49]  D. Pappalardo,et al.  Isotactic-Specific Polymerization of Propene by a Cs-Symmetric Zirconium(IV) Complex Bearing a Dianionic Tridentate [−NNN−] Amidomethylpyrrolidepyridine Ligand , 2009 .

[50]  Lawrence R Sita,et al.  Ex uno plures ("out of one, many"): new paradigms for expanding the range of polyolefins through reversible group transfers. , 2009, Angewandte Chemie.

[51]  T. Marks,et al.  Catalyst Nuclearity Effects in Olefin Polymerization. Enhanced Activity and Comonomer Enchainment in Ethylene + Olefin Copolymerizations Mediated by Bimetallic Group 4 Phenoxyiminato Catalysts , 2009 .

[52]  D. Pappalardo,et al.  Bis[(amidomethyl)pyridine] Zirconium(IV) Complexes: Synthesis, Characterization, and Activity as Olefin Polymerization Catalysts† , 2009 .

[53]  T. Marks,et al.  Synthesis, characterization, and marked polymerization selectivity characteristics of binuclear phenoxyiminato organozirconium catalysts. , 2008, Journal of the American Chemical Society.

[54]  G. Solan,et al.  Bis(imino)pyridines: surprisingly reactive ligands and a gateway to new families of catalysts. , 2007, Chemical reviews.

[55]  G. Coates,et al.  Living alkene polymerization : New methods for the precision synthesis of polyolefins , 2007 .

[56]  T. Marks,et al.  Nuclearity and cooperativity effects in binuclear catalysts and cocatalysts for olefin polymerization , 2006, Proceedings of the National Academy of Sciences.

[57]  C. Lamberti,et al.  The structure of active centers and the ethylene polymerization mechanism on the Cr/SiO2 catalyst: a frontier for the characterization methods. , 2005, Chemical reviews.

[58]  I. Beletskaya,et al.  Palladium‐Catalysed Amination of 1,8‐ and 1,5‐Dichloroanthracenes and 1,8‐ and 1,5‐Dichloroanthraquinones , 2005 .

[59]  T. Marks,et al.  Polynuclear olefin polymerization catalysis: proximity and cocatalyst effects lead to significantly increased polyethylene molecular weight and comonomer enchainment levels. , 2004, Angewandte Chemie.

[60]  W. Kaminsky,et al.  The discovery of metallocene catalysts and their present state of the art , 2004 .

[61]  G. Wilke.  Fifty years of Ziegler catalysts: consequences and development of an invention. , 2003, Angewandte Chemie.

[62]  Vince Murphy,et al.  A fully integrated high-throughput screening methodology for the discovery of new polyolefin catalysts: discovery of a new class of high temperature single-site group (IV) copolymerization catalysts. , 2003, Journal of the American Chemical Society.

[63]  V. C. Gibson,et al.  Advances in non-metallocene olefin polymerization catalysis. , 2003, Chemical reviews.

[64]  T. Marks,et al.  Catalyst/cocatalyst nuclearity effects in single-site polymerization. Enhanced polyethylene branching and alpha-olefin comonomer enchainment in polymerizations mediated by binuclear catalysts and cocatalysts via a new enchainment pathway. , 2002, Journal of the American Chemical Society.

[65]  P. Rinaldi,et al.  Poly(ethylene-co-1-octene) Characterization by High-Temperature Multidimensional NMR at 750 MHz , 2001 .

[66]  T. Marks,et al.  Cocatalysts for metal-catalyzed olefin polymerization: activators, activation processes, and structure-activity relationships. , 2000, Chemical reviews.

[67]  L. Cavallo,et al.  Selectivity in propene polymerization with metallocene catalysts. , 2000, Chemical reviews.

[68]  G. Britovsek,et al.  The Search for New-Generation Olefin Polymerization Catalysts: Life beyond Metallocenes. , 1999, Angewandte Chemie.

[69]  G. Diamond,et al.  EFFICIENT SYNTHESIS OF CHIRAL ANSA-METALLOCENES BY AMINE ELIMINATION. SYNTHESIS, STRUCTURE, AND REACTIVITY OF RAC-(EBI)ZR(NME2)2 , 1996 .

[70]  I. Kim,et al.  Propylene polymerization with ansa-metallocene amide complexes , 1996 .