Skip to main content
SpringerLink
Log in

Investigating the Effects of Para-methoxy Substitution in Sterically Enhanced Unsymmetrical Bis(arylimino)pyridine-cobalt Ethylene Polymerization Catalysts

  • Research Article
  • Published:
Chinese Journal of Polymer Science Aims and scope Submit manuscript

Abstract

A group of five bis(arylimino)pyridine-cobalt(II) chloride complexes, [2-{(2,6-(Ph2CH)2-4-MeOC6H2)N=CMe}-6-(ArN=CMe)C5H3N]CoCl2 (Ar = 2,6-Me2C6H3 Co1, 2,6-Et2C6H3 Co2, 2,6-iPr2C6H3 Co3, 2,4,6-Me3C6H2 Co4, 2,6-Et2-4-MeC6H2 Co5), each containing one N-4-methoxy-2,6-dibenzhydrylphenyl group and one smaller sterically/electronically variable N-aryl group, have been synthesized in good yield (>71%) from the corresponding neutral terdentate nitrogen-donor precursor, L1–L5. All complexes have been characterized by 1H-NMR and FTIR spectroscopy with the former highlighting the paramagnetic nature of these cobaltous species and the unsymmetrical nature of the chelating ligand. The molecular structures of Co3 and Co4 emphasize the steric differences of the two inequivalent N-aryl groups and the distorted square pyramidal geometry about the metal centers. In the presence of MAO or MMAO, Co1–Co5 collectively displayed high activities for ethylene polymerization producing high molecular weight polyethylenes that, in general, exhibited narrow dispersities (Mw/Mn values: 2.12–4.07). Notably, the least sterically hindered Co1 when activated with MAO was the most productive (6.92×106 gPE·mol−1(Co)·h−1) at an operating temperature of 60 ºC. Conversely, the most sterically hindered Co3/MMAO produced the highest molecular weight polyethylene (Mw=6.29×105 g·mol−1). All the polymers displayed high linearity as demonstrated by their melting temperatures (>130 °C) and their 1H- and 13C-NMR spectra. By comparison of Co1 with its para-methyl, -chloro and -nitro counterparts, the presence of the para-methoxy substituent showed the most noticeable effect of enhancing the thermal stability of the catalyst.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Johnson, L. K.; Killian, C. M.; Brookhart, M. New Pd(II)- and Ni(II)-based catalysts for polymerization of ethylene and α-olefins. J. Am. Chem. Soc. 1995, 117, 6414–6415.

    Article  CAS  Google Scholar 

  2. Killian, C. M.; Tempel, D. J.; Johnson, L. K.; Brookhart, M. Livíng polymerization of α-olefins using Ni(N)-α-diimine catalysts. synthesis of new block polymers based on α-olefins. J. Am. Chem. Soc. 1996, 118, 11664–11665.

    Article  CAS  Google Scholar 

  3. Small, B. L.; Brookhart, M.; Bennett, A. M. A. Highly active iron and cobalt catalysts for the polymerization of ethylene. J. Am. Chem. Soc. 1998, 120, 4049–4050.

    Article  CAS  Google Scholar 

  4. Britovsek, G. P. J.; Gibson, V. C.; Kimberley, B. S.; Maddox, P. J.; McTavish, S. J.; Solan, G. A.; White A. J. P.; Williams, D. J. Novel olefin polymerization catalysts based on iron and cobalt. Chem. Commun. 1998, 7, 849–850.

    Article  Google Scholar 

  5. Britovsek, G. J. P.; Bruce, M.; Gibson, V. C.; Kimberley, B. S.; Maddox, P. J.; Mastroianni, S.; McTavish, S. J.; Redshaw, C.; Solan, G. A.; Strömberg, S. White, A. J. P. Williams, D. J. Iron and cobalt ethylene polymerization catalysts bearing 2,6-bis(imino)pyridyl ligands: synthesis, structures, and polymerization studies. J. Am. Chem. Soc. 1999, 121, 8728–8740.

    Article  CAS  Google Scholar 

  6. Harth, E. M.; Hecht, S.; Helms, B.; Malmstrom, E. E.; Fréchet, J. M. J.; Hawker, C. J. The effect of macromolecular architecture in nanomaterials: a comparison of site isolation in porphyrin core dendrimers and their isomeric linear analogues. J. Am. Chem. Soc. 2002, 124, 3926–3938.

    Article  CAS  PubMed  Google Scholar 

  7. Gibson, V. C.; Redshaw, C.; Solan, G. A. Bis(imino)pyridines: surprisingly reactive ligands and a gateway to new families of catalysts. Chem. Rev. 2007, 107, 1745–1776.

    Article  CAS  PubMed  Google Scholar 

  8. Gibson, V. C.; Solan, G. A. Iron-based and cobalt-based olefin polymerisation catalysts. Top. Organomet. Chem. 2009, 26, 107–158.

    CAS  Google Scholar 

  9. Gibson, V. C.; Solan, G. A. Olefin oligomerizations and polymerizations catalyzed by iron and cobalt complexes bearing bis(imino)pyridine ligands. Wiley-VCH, Weinheim 2010, 5, 111–141.

    Google Scholar 

  10. Bianchini, C.; Giambastiani, G.; Luconi, L.; Meli, A. Olefin oligomerization, homopolymerization and copolymerization by late transition metals supported by (imino)pyridine ligands. Coord. Chem. Rev. 2010, 254, 431–455.

    Article  CAS  Google Scholar 

  11. Ma, J.; Feng, C.; Wang, S. L.; Zhao, K. Q.; Sun, W. H.; Redshaw, C.; Solan, G. A. Bi- and tri-dentate imino-based iron and cobalt pre-catalysts for ethylene oligo-/polymerization. Inorg. Chem. Front. 2014, 1, 14–34.

    Article  CAS  Google Scholar 

  12. Flisak, Z.; Sun, W. H. Progression of diiminopyridines: from single application to catalytic versatility. ACS Catal. 2015, 5, 4713–4724.

    Article  CAS  Google Scholar 

  13. Small, B. L. Discovery and development of pyridine-bis(imine) and related catalysts for olefin polymerization and oligomerization. Acc. Chem. Res. 2015, 48, 2599–2611.

    Article  CAS  PubMed  Google Scholar 

  14. Wang, Z.; Liu, Q.; Solan, G. A.; Sun, W. H. Recent advances in Nimediated ethylene chain growth: Nimine-donor ligand effects on catalytic activity, thermal stability and oligo-/polymer structure. Coord. Chem. Rev. 2017, 350, 68–83.

    Article  CAS  Google Scholar 

  15. Wang, Z.; Solan, G. A.; Zhang, W. J.; Sun, W. H. Carbocyclic-fused N, N, N-pincer ligands as ring-strain adjustable supports for iron and cobalt catalysts in ethylene oligo-/polymerization. Coord. Chem. Rev. 2018, 363, 92–108.

    Article  CAS  Google Scholar 

  16. Bariashir, C.; Huang, C.; Solan, G. A.; Sun, W. H. Recent advances in homogeneous chromium catalyst design for ethylene tri-, tetra-, oligo- and polymerization. Coord. Chem. Rev. 2019, 385, 208–229.

    Article  CAS  Google Scholar 

  17. Mitchell, N. E.; Long, B. K. Recent advances in thermally robust, late transition metal-catalyzed olefin polymerization. Polym. Int. 2019, 68, 14–26.

    Article  CAS  Google Scholar 

  18. Yuan, S. F.; Yan, Y.; Solan, G. A.; Ma, Y.; Sun, W. H. Recent advancements in N-ligated group 4 molecular catalysts for the (co)polymerization of ethylene. Coord. Chem. Rev. 2020, 411, 213254.

    Article  CAS  Google Scholar 

  19. Britovsek, G. J. P.; Gibson, V. C.; Kimberley, B. S.; Mastroianni, S.; Redshaw, C.; Solan, G. A.; White, A. J. P.; Williams, D. J. Bis(imino)pyridyl iron and cobalt complexes: the effect of nitrogen substituents on ethylene oligomerisation and polymerization. J. Chem. Soc. Dalton Trans. 2001, 1639–1644.

    Google Scholar 

  20. McTavish, S.; Britovsek, G. J. P.; Smit, T. M.; Gibson, V. C.; White, A. J. P.; Williams, D. J. Iron-based ethylene polymerization catalysts supported by bis(imino)pyridine ligands: derivatization via deprotonation/alkylation at the ketimine methyl position. J. Mol. Catal. A: Chem. 2007, 261, 293–300.

    Article  CAS  Google Scholar 

  21. Smit, T. M.; Tomov, A. K.; Britovsek, G. J. P.; Gibson, V. C.; White, A. J. P.; Williams, D. J. The effect of imine-carbon substituents in bis(imino)pyridine-based ethylene polymerisation catalysts across the transition series. Catal. Sci. Technol. 2012, 2, 643–655.

    Article  CAS  Google Scholar 

  22. Zhang, W.; Sun, W. H.; Redshaw, C. Tailoring iron complexes for ethylene oligomerization and/or polymerization. Dalton Trans. 2013, 42, 8988–8997.

    Article  CAS  PubMed  Google Scholar 

  23. Yue, E.; Zeng, Y.; Zhang, W.; Sun, Y.; Cao, X. P.; Sun, W. H. Highly linear polyethylenes using the 2-(1-(2,4-dibenzhydryl-naphthylimino)ethyl)-6-(1-(arylimino)ethyl)-pyridylcobalt chlorides: synthesis, characterization and ethylene polymerization. Sci. China Chem. 2016, 59, 1291–1300.

    Article  CAS  Google Scholar 

  24. Yang, W.; Yi, J.; Ma, Z.; Sun, W. H. 2D-QSAR modeling on the catalytic activities of 2-azacyclyl-6- aryliminopyridylmetal precatalysts in ethylene oligomerization. Cat. Commun. 2017, 101, 40–43.

    Article  CAS  Google Scholar 

  25. Bariashir, C.; Wang, Z.; Du, S.; Solan, G. A.; Huang, C.; Liang, T.; Sun, W. H. Cycloheptyl-fused NNO-ligands as electronically modifiable supports for M(II) (M=Co,Fe) chloride precatalysts; probing performance in ethylene oligo-/polymerization. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3980–3989.

    Article  CAS  Google Scholar 

  26. Zhang, S.; Sun, W. H.; Xiao, T.; Hao, X. Ferrous and cobaltous chlorides bearing 2,8-bis(imino)quinolines: highly active catalysts for ethylene polymerization at high temperature. Organometallics 2010, 29, 1168–1173.

    Article  CAS  Google Scholar 

  27. Sun, W.-H.; Hao, P.; Li, G.; Zhang, S.; Wang, W.; Yi, J. Synthesis and characterization of iron and cobalt dichloride bearing 2-quinoxalinyl-6-iminopyridines and their catalytic behavior toward ethylene reactivity. J. Organomet. Chem. 2007, 692, 4506–4518.

    Article  CAS  Google Scholar 

  28. Wang, K.; Wedeking, K.; Zuo, W.; Zhang, D.; Sun, W. H. Iron(II) and cobalt(II) complexes bearing N-((pyridin-2-yl)methylene)-quinolin-8-amine derivatives: Synthesis and application to ethylene oligomerization. J. Organomet. Chem. 2008, 693, 1073–1080.

    Article  CAS  Google Scholar 

  29. Wang, L.; Sun, W. H.; Han, L.; Yang, H.; Hu, Y.; Jin, X. Late transition metal complexes bearing 2,9-bis(imino)-1,10-phenanthrolinyl ligands: synthesis, characterization and their ethylene activity. J. Organomet. Chem. 2002, 658, 62–70.

    Article  CAS  Google Scholar 

  30. Sun, W. H.; Jie, S.; Zhang, S.; Zhang, W.; Song, Y.; Ma, H. Iron complexes bearing 2-imino-1,10-phenanthrolinyl ligands as highly active catalysts for ethylene oligomerization. Organometallics 2006, 25, 666–677.

    Article  CAS  Google Scholar 

  31. Pelletier, J. D. A.; Champouret, Y. D. M.; Cardarso, J.; Clowes, L.; Gañete, M.; Singh, K.; Thanarajasingham, V.; Solan, G. A. Electronically variable imino-phenanthrolinyl-cobalt complexes; synthesis, structures and ethylene oligomerisation studies. J. Organomet. Chem. 2006, 691, 4114–4123.

    Article  CAS  Google Scholar 

  32. Jie, S.; Zhang, S.; Wedeking, K.; Zhang, W.; Ma, H.; Lu, X.; Deng, Y.; Sun, W. H. Cobalt(II) complexes bearing 2-imino-1,10-phenanthroline ligands: synthesis, characterization and ethylene oligomerization. C. R. Chim. 2006, 9, 1500–1509.

    Article  CAS  Google Scholar 

  33. Jie, S.; Zhang, S.; Sun, W. H.; Kuang, X.; Liu, T.; Guo, J. Iron(II) complexes ligated by 2-imino-1,10-phenanthrolines: Preparation and catalytic behavior toward ethylene oligomerization. J. Mol. Catal. A: Chem. 2007, 269, 85–96.

    Article  CAS  Google Scholar 

  34. Jie, S.; Zhang, S.; Sun, W. H. 2-Arylimino-9-phenyl-1,10-phenanthrolinyl-iron, -cobalt and -nickel complexes: synthesis, characterization and ethylene oligomerization behavior. Eur. J. Inorg. Chem. 2007, 2007, 5584–5598.

    Article  Google Scholar 

  35. Sun, W. H.; Hao, P.; Zhang, S.; Shi, Q.; Zuo, W.; Tang, X. Iron(II) and cobalt(II) 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridyl complexes as catalysts for ethylene oligomerization and polymerization. Organometallics 2007, 26, 2720–2734.

    Article  CAS  Google Scholar 

  36. Chen, Y.; Hao, P.; Zuo, W.; Gao, K.; Sun, W. H. 2-(1-Isopropyl-2-benzimidazolyl)-6-(1-aryliminoethyl)- pyridyl transition metal (Fe, Co, and Ni) dichlorides: Syntheses, characterizations and their catalytic behaviors toward ethylene reactivity. J. Organomet. Chem. 2008, 693, 1829–1840.

    Article  CAS  Google Scholar 

  37. Gao, R.; Li, Y.; Wang, F.; Sun, W. H.; Bochmann, M. 2-Benzoxazolyl-6-[1-(arylimino)ethyl]- pyridyliron(II) chlorides as ethylene oligomerization catalysts. Eur. J. Inorg. Chem. 2009, 691, 4149–4156.

    Article  Google Scholar 

  38. Xiao, L.; Gao, R.; Zhang, M.; Li, Y.; Cao, X.; Sun, W. H. 2-(1H-2-benzimidazolyl)-6- (1-(arylimino)ethyl)pyridyl iron(ii) and cobalt(ii) dichlorides: syntheses, characterizations, and catalytic behaviors toward ethylene reactivity. Organometallics 2009, 28, 2225–2233.

    Article  CAS  Google Scholar 

  39. Yu, J.; Huang, W.; Wang, L.; Redshaw, C.; Sun, W. H. 2-[1-(2,6-Dibenzhydryl-4-methylphenylimino)-ethyl]-6-[1-(arylimino)ethyl]- pyridylcobalt(II) dichlorides: synthesis, characterization and ethylene polymerization behavior. Dalton Trans. 2011, 40, 10209–10214.

    Article  CAS  PubMed  Google Scholar 

  40. He, F.; Zhao, W.; Cao, X. P.; Liang, T.; Redshaw, C.; Sun, W. H. 2-[1-(2,6-Dibenzhydryl-4-chlorophenylimino)ethyl]-6-[1-arylimino-ethyl]pyridyl cobalt dichlorides: synthesis, characterization and ethylene polymerization behavior. J. Organomet. Chem. 2012, 713, 209–216.

    Article  CAS  Google Scholar 

  41. Mahmood, Q.; Ma, Y.; Hao, X.; Sun, W. H. Substantially enhancing the catalytic performance of bis(imino)pyridylcobaltous chloride pre-catalysts adorned with benzhydryl and nitro groups for ethylene polymerization. Appl. Organomet. Chem. 2019, 33, e4857.

    Article  Google Scholar 

  42. Zhang, W.; Wang, S.; Du, S.; Guo, C. Y.; Hao, X.; Sun, W. H. 2-(1-(2,4-Bis((di(4-fluorophenyl)methyl)-6-methylphenylimino)ethyl)-6-(1-(arylimino)ethyl)pyridylmetal (iron or cobalt) complexes: synthesis, characterization and ethylene polymerization behavior. Macromol. Chem. Phys. 2014, 215, 1797–1890.

    Article  CAS  Google Scholar 

  43. Sun, W. H.; Zhao, W.; Yu, J.; Zhang, W.; Hao, X.; Redshaw, C. Enhancing the activity and thermal stability of iron precatalysts using 2-(1-{2,6-bis[bis(4-fluorophenyl)methyl]-4-methylphenylimino} ethyl)-6-[1-(arylimino)ethyl]pyridines. Macromol. Chem. Phys. 2012, 213, 1266–1273.

    Article  CAS  Google Scholar 

  44. Liu, T.; Ma, Y. P.; Solan, G. A.; Liang, T.; Sun, W. H. Exploring ortho-(4,4′-dimethoxybenzhydryl) substitution in iron ethylene polymerization catalysts: co-catalyst effects, thermal stability, and polymer molecular weight variations. Appl. Organomet. Chem. 2021, 35, e6259.

    Article  CAS  Google Scholar 

  45. Meiries, S.; Speck, K.; Cordes, D. B.; Slawin, A. M. Z.; Nolan, S. P. [Pd(IPr*OMe)(acac)Cl]: tuning the N-heterocyclic carbene in catalytic C-N bond formation. Orgnometallics 2012, 32, 330–339.

    Article  Google Scholar 

  46. Wu, R.; Wang, Y.; Zhang, R. N; Guo, C. Y.; Flisak, Z.; Sun, Y.; Sun, W. H. Finely tuned nickel complexes as highly active catalysts affording branched polyethylene of high molecular weight: 1-(2,6-dibenzhydryl-4-methoxyphenylimino)-2-(arylimino)acenaphthylenenickel halides. Polymer 2018, 153, 574–586.

    Article  CAS  Google Scholar 

  47. Wang, S.; Zhao, W.; Hao, X.; Li, B.; Redshaw, C.; Li, Y.; Sun, W.-H. 2-(1-{2,6-Bis[bis(4-fluorophenyl-methyl]-4-methylpheny-limino}ethyl)-6-[1-(arylimino)ethyl]pyridylcobalt dichlorides: synthesis, characterization and ethylene polymerization behavior. J. Organomet. Chem. 2013, 731, 78–84.

    Article  CAS  Google Scholar 

  48. Lai, J.; Zhao, W.; Yang, W.; Redshaw, C.; Liang, T.; Liu, Y.; Sun, W. H. 2-[1-(2,4-Dibenzhydryl-6-methylphenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridylcobalt(II) dichlorides: synthesis, characterization and ethylenepolymerization behavior. Polym. Chem. 2012, 3, 787–793.

    Article  CAS  Google Scholar 

  49. Du, S.; Kong, S.; Shi, Q.; Mao, J.; Guo, C.; Yi, J.; Liang, T.; Sun, W. H. Enhancing the activity and thermal stability of nickel complex precatalysts using 1-[2,6-bis(bis(4-fluorophenyl)-methyl)-4-methyl phenylimino]-2-aryliminoacenaphthylene derivatives. Organometallics 2015, 34, 582–590.

    Article  CAS  Google Scholar 

  50. Wang, S.; Li, B.; Liang, T.; Redshaw, C.; Li, Y.; Sun, W. H. Synthesis, characterization and catalytic behavior toward ethylene of 2-[1-(4,6-dimethyl-2-benzhydrylphenylimino)ethyl]-6-[1-(arylimino)-ethyl]- pyridylmetal (iron or cobalt) chlorides. Dalton Trans. 2013, 42, 9188–9197.

    Article  CAS  PubMed  Google Scholar 

  51. Zhang, R.; Ma, Y.; Han, M.; Solan, G. A.; Pi, Y.; Sun, Y.; Sun, W. H. Exceptionally high molecular weight linear polyethylene by using N,N,N′-Co catalysts appended with a N′-2,6-bis{d44-fluorophenyl) methyl}-4-nitrophenyl group. Appl. Organomet. Chem. 2019, 33, e5175.

    Article  Google Scholar 

  52. Du, S.; Zhang, W.; Yue, E.; Huang, F.; Liang, T.; Sun, W. H. a,a′-Bis(arylimino)-2,3,5,6-bis- (pentamethylene)pyridylcobalt chlorides: synthesis, characterization and ethylene polymerization behavior. Eur. J. Inorg. Chem. 2016, 1748–1755.

    Google Scholar 

  53. Du, S.; Wang, X.; Zhang, W.; Flisak, Z.; Sun, Y.; Sun, W. H. A practical ethylene polymerization for vinyl-polyethylenes: synthesis, characterization and catalytic behavior of a,a′-bisimino-2,3,5,6- bis(pentamethylene)pyridyliron chlorides. Polym. Chem. 2016, 7, 4188–4197.

    Article  CAS  Google Scholar 

  54. Han, M.; Zhang, Q.; Oleynik, I. I.; Suo, H.; Solan, G. A.; Oleynik, I.V.; Ma, Y.; Liang, T.; Sun, W. H. High molecular weight polyethylenes of narrow dispersity promoted using bis(arylimino) cyclohepta[b]pyridine-cobalt catalysts orthosubstituted with benzhydryl & cycloalkyl groups. Dalton Trans. 2020, 49, 4774–4784.

    Article  CAS  PubMed  Google Scholar 

  55. Huang, F.; Zhang, W.; Sun, Y.; Hu, X.; Solan, G. A.; Sun, W. H. Thermally stable and highly active cobalt precatalysts for vinylpolyethylenes with narrow polydispersities: integrating fusedring and imino-carbon protection into ligand design. New J. Chem. 2016, 40, 8012–8023.

    Article  CAS  Google Scholar 

  56. Suo, H.; Oleynik, I. I.; Bariashir, C.; Oleynik, I.; Wang, Z.; Solan, G. A.; Ma, Y.; Liang, T.; Sun, W. H. Strictly linear polyethylene using co-catalysts chelated by fused bis(arylimino)pyridines: probing ortho-cycloalkyl ring-size effects on molecular weight. Polymer 2018, 149, 45–54.

    Article  CAS  Google Scholar 

  57. Guo, J.; Wang, Z.; Zhang, W.; Oleynik, I. I.; Vignesh, A.; Oleynik, I. V.; Hu, X.; Sun, Y.; Sun, W. H. Highly linear polyethylenes achieved using thermo-stable and efficient cobalt precatalysts bearing carbocyclic-fused N, N, N-pincer ligand. Molecules 2019, 24, 1176.

    Article  PubMed Central  Google Scholar 

  58. Bariashir, C.; Wang, Z.; Suo, H.; Zada, M.; Solan, G. A.; Ma, Y.; Liang, T.; Sun, W. H. Narrow dispersed linear polyethylene using cobalt catalysts bearing cycloheptyl-fused bis(imino)pyridines; probing the effects of ortho-benzhydryl substitution. Eur. Polym. J. 2019, 110, 240–251.

    Article  CAS  Google Scholar 

  59. Huang, Y.; Zhang, R.; Liang, T.; Hu, X.; Solan, G. A.; Sun, W. H. Selectivity effects on N, N, N′-cobalt catalyzed ethylene dimerization/trimerization dictated through choice of aluminoxane cocatalyst. Organometallics 2019, 38, 1143–1150.

    Article  CAS  Google Scholar 

  60. Zada, M.; Vignesh, A.; Suo, H.; Ma, Y.; Liu, H.; Sun, W. H. N, N, N-type iron(II) complexes consisting sterically hindered dibenzocycloheptyl group: synthesis and catalytic activity towards ethylene polymerization. Mol. Catal. 2020, 492, 110981.

    Article  CAS  Google Scholar 

  61. Han, M.; Zhang, Q.; Oleynik, I. I.; Suo, H.; Oleynik, I. V.; Solan, G. A.; Ma, Y.; Liang, T.; Sun, W. H. Adjusting ortho-cycloalkyl ring size in a cycloheptyl-fused N,N,N-iron catalyst as means to control catalytic activity and polyethylene properties. Catalysts 2020, 10, 1002.

    Article  CAS  Google Scholar 

  62. Yuan, S. F.; Fan, Z.; Yan, Y.; Ma, Y.; Han M.; Liang, T.; and Sun, W. H. Achieving polydispersive HDPE by N, N, N-Co precatalysts appended with N-2,4-bis(di(4-methoxyphenyl)methyl)-6-methylphenyl. RSC Adv. 2020, 10, 43400–43411.

    Article  CAS  Google Scholar 

  63. Yuan, S. F.; Fan, Z.; Han M.; Yan, Y.; Flisak, Z.; Ma, Y.; Liang, T.; Sun, W. H. Enhancing performance of bis(arylimino)pyridine-iron precatalyst for ethylene polymerization by substitution with the 2,4-bis(4,4′-dimethoxybenzhydryl)-6-methylphenyl group. Eur. Polym. J. 2021, 16, 1571–1580.

    Google Scholar 

  64. Guo, L.; Gao, H.; Zhang, L.; Zhu, F.; Wu, Q. An unsymmetrical iron(II) bis(imino)pyridyl catalyst for ethylene polymerization: effect of a bulky ortho substituent on the thermostability and molecular weight of polyethylene. Organometallics 2010, 29, 2118–2125.

    Article  CAS  Google Scholar 

  65. Zhao, W.; Yue, E.; Wang, X.; Yang, W.; Chen, Y.; Hao, X.; Cao, X.; Sun, W. H. Activity and stability spontaneously enhanced toward ethylene polymerization by employing 2-(1-(2,4-dibenzhydryl-naphthylimino)ethyl)-6-(1-(arylimino)ethyl) pyridyliron(II) dichlorides. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 988–996.

    Article  CAS  Google Scholar 

  66. Ionkin, A. S.; Marshall, W. J.; Adelman, D. J.; Fones, B. B.; Fish, B. M.; Schiauer, M. F. Modification of iron(II) tridentate bis(imino)pyridine complexes by a boryl group for the production of α-olefins at high temperature. Organometallics 2008, 27, 1902–1911.

    Article  CAS  Google Scholar 

  67. Zhang, R; Han, M.; Ma, Y.; Solan, G. A.; Liang, T.; Sun, W. H. Steric and electronic modulation of iron catalysts as a route to remarkably high molecular weight linear polyethylenes. Dalton Trans. 2019, 48, 17488–17498.

    Article  CAS  PubMed  Google Scholar 

  68. Mahmood, Q.; Yue, E.; Guo, J.; Zhang, W.; Ma, Y.; Hao, X.; Sun, W. H. Nitro-functionalized bis(imino)pyridylferrous chlorides as thermo-stable precatalysts for linear polyethylenes with high molecular weights. Polymer 2018, 159, 124–137.

    Article  CAS  Google Scholar 

  69. Ba, J.; Du, S.; Yue, E.; Hu, X.; Flisak, Z.; Sun, W. H. Constrained formation of 2-(1-(arylimino)ethyl)-7-arylimino-6,6-dimethylcyclo-pentapyridines and their cobalt(II) chloride complexes: synthesis, characterization and ethylene polymerization. RSC Adv. 2015, 5, 32720–32729.

    Article  CAS  Google Scholar 

  70. Appukuttan, V. K.; Liu, Y.; Son, B. C.; Ha, C. S.; Suh, H.; Kim, I. Iron and cobalt complexes of 2,3,7,8-tetrahydroacridine-4,-5(1H,6H)-diimine sterically modulated by substituted aryl rings for the selective oligomerization to polymerization of ethylene. Organometallics 2011, 30, 2285–2294.

    Article  CAS  Google Scholar 

  71. Sun, W. H.; Kong, S.; Chai, W.; Shiono, T.; Redshaw, C.; Hu, X.; Guo, C.; Hao, X. 2-(1-(Arylimino)ethyl)-8-arylimino-5,6,7-trihydroquinolylcobalt dichloride: synthesis and polyethylene wax formation. Appl. Catal. Gen. 2012, 447–448.

    Google Scholar 

  72. Huang, F.; Zhang, W.; Yue, E.; Liang, T.; Hu, X.; Sun, W. H. Controlling the molecular weights of polyethylene waxes using the highly active precatalysts of 2-(1-aryliminoethyl)-9-arylimino-5,6,7,8-tetrahydrocycloheptapyridylcobalt chlorides: synthesis, characterization and catalytic behavior. Dalton Trans. 2016, 45, 657–666.

    Article  CAS  PubMed  Google Scholar 

  73. Wang, Z.; Solan, G. A.; Mahmood, Q.; Liu, Q.; Ma, Y.; Hao, X.; Sun, W. H. Bis(imino)pyridines incorporating doubly fused eight-membered rings as conformationally flexible supports for cobalt ethylene polymerization catalysts. Organometallics 2018, 37, 380–389.

    Article  CAS  Google Scholar 

  74. Zhang, Q.; Wu, N.; Xiang, J.; Solan, G. A. Suo, H.; Ma, Y.; Liang, T.; Sun, W. H. Bis-cycloheptyl-fused bis(imino)pyridine-cobalt catalysts for PE wax formation: positive effects of fluoride substitution on catalytic performance and thermal stability. Dalton Trans. 2020, 49, 9425–9437.

    Article  CAS  PubMed  Google Scholar 

  75. Zhang, Q.; Zhang, R.; Han, M.; Yang, W.; Liang, T.; Sun, W. H. 4,4′-Difluorobenzhydryl-modified bis(imino)-pyridyliron(II) chlorides as thermally stable precatalysts for strictly linear polyethylenes with narrow dispersities. Dalton Trans. 2020, 49, 7384–7396.

    Article  CAS  PubMed  Google Scholar 

  76. Zhao, W.; Yu, J.; Song, S.; Yang, W.; Liu, H.; Hao, X.; Redshaw, C.; Sun, W. H. Controlling the ethylene polymerization parameters in iron pre-catalysts of the type 2-[1-(2,4-dibenzhydryl-6-methyl-phenylimino)ethyl]-6-[1-(arylimino)ethyl] pyridyliron dichloride. Polymer 2012, 53, 130–137.

    Article  CAS  Google Scholar 

  77. Cao, X.; He, F.; Zhao, W.; Cai, Z.; Hao, X.; Shiono, T.; Redshaw, C.; Sun, W. H. 2-[1-(2,6-Dibenzhydryl-4-chlorophenylimino)ethyl]-6-1-(arylimino)ethyl] pyridyliron(II) dichlorides: synthesis, characterization and ethylene polymerization behavior. Polymer 2012, 53, 1870–1880.

    Article  CAS  Google Scholar 

  78. Zhang, Q.; Ma, Y.; Suo, H.; Solan, G. A.; Liang, T.; Sun, W. H. Co-catalyst effects on the thermal stability/activity of N, N, N-co ethylene polymerization catalysts bearing fluoro-substituted N-2,6-dibenzhydrylphenyl groups. Appl. Organomet. Chem. 2019, 33, e5134.

    Article  Google Scholar 

Download references

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (No. 21871275). G.A.S. thanks the Chinese Academy of Sciences for a President’s International Fellowship for Visiting Scientists.

Author information

Authors and Affiliations

  1. Institute of Applied Chemistry, Shanxi University, Taiyuan, 030006, China

    Yi Yan & Shi-Fang Yuan

  2. Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China

    Yi Yan, Ming Liu, Gregory A. Solan, Yan-Ping Ma, Tong-Ling Liang & Wen-Hua Sun

  3. Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, UK

    Gregory A. Solan

  4. State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China

    Wen-Hua Sun

Authors
  1. Yi Yan
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Shi-Fang Yuan
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ming Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Gregory A. Solan
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Yan-Ping Ma
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Tong-Ling Liang
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Wen-Hua Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Shi-Fang Yuan, Gregory A. Solan or Wen-Hua Sun.

Additional information

Notes

The authors declare no competing financial interest.

Electronic Supplementary Information for

10118_2022_2670_MOESM1_ESM.pdf

Investigating the Effects of Para-methoxy Substitution in Sterically Enhanced Unsymmetrical Bis(arylimino)pyridine-cobalt Ethylene Polymerization Catalysts

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yan, Y., Yuan, SF., Liu, M. et al. Investigating the Effects of Para-methoxy Substitution in Sterically Enhanced Unsymmetrical Bis(arylimino)pyridine-cobalt Ethylene Polymerization Catalysts. Chin J Polym Sci 40, 266–279 (2022). https://doi.org/10.1007/s10118-022-2670-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10118-022-2670-z

Keywords

Search

Navigation