Halogen substituted iron(III) di(imino)pyridine complexes as catalysts for 1-pentene/1-hexene co-oligomerization reactions

Document Type : Original research

Authors

Laboratorium für Anorganische Chemie, Universität Bayreuth Postfach 101251, 95440 Bayreuth, Germany

Abstract

Nine different bis(arylimino)pyridine complexes of Fe(III) with different halide substituents (F, Cl, Br, I) at different positions of the iminophenyl group of the ligand have been synthesized, characterized and applied for homogeneous 1-pentene and 1-hexene oligomerization and co-oligomerization reactions after activation with methylaluminoxane (MAO). The best activity in 1-hexene oligomerization (152 kg/mol.h) was observed for 4/ MAO with an iodine substituent in para position of the iminophenyl group. Fluorine substituents in the meta position of the iminophenyl group proved as disadvantageous (1 kg/mol.h) in homo-oligomerization reactions but advantageous in co-oligomerization reactions of 1-pentene and 1-hexene. Obviously, tiny electronic or steric differences at the active sites of the corresponding catalysts are responsible for this result (structure-property relationship). The product distributions of the co-dimerization reactions of 1-pentene and 1-hexene reflected a binominal behaviour with dominating co-products. The ratio of dimers is 1:2:1 (C10:C11:C12) while the trimers (pentadecenes up to octadecenes) show proportions of 1:3:3:1.

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  1. Sauter DW, Taoufik M, Boisson C (2017) Poly­olefins, a successful story. Polymers 9: 185
  2. Chen C (2018) Designing catalysts for olefin po­lymerization beyond electronic and steric tuning. Nat Rev Chem 2: 6-14
  3. Zhang R, Han M, Ma Y, Solan GA, Liang T, Sun W-H (2019) Steric and electronic modulation of iron catalysts as a route to remarkably high molecular weight linear polyethylenes. Dalton Trans 48: 17488-17498
  4. Flisak Z, Sun W-H (2015) Progression of diimi­nopyridines: from single application to catalytic versatility. ACS Catal 5: 4713-4724
  5. Chirik PJ (2017) Carbon-carbon bond forma­tion in a weak ligand field: Leveraging open-shell first-row transition-metal catalysts. Angew Chem Int Edit 56: 5170-5181
  6. Ittel SD, Johnson LK, Brookhart M (2000) Late-metal catalysts for ethylene homo-and copoly­merization. Chem Rev 100: 1169-1204
  7. Gibson VC, Redshaw C, Solan GA (2007) Bis (imino) pyridines: surprisingly reactive ligands and a gateway to new families of catalysts. Chem Rev 107: 1745-1776
  8. Weliange NM, McGuinness DS, Gardiner MG, J Patel (2016) Cobalt-bis (imino) pyridine com­plexes as catalysts for hydroalumination–isom­erisation of internal olefins. Dalton Trans 45: 10842-1089
  9. Antonov AA, Semikolonova NV, Zakharov VA, Zhang W, Wang Y, Sun W, Talsi EP, Bryliakov KP (2012) Vinyl polymerization of norbornene on nickel complexes with bis (imino) pyridine ligands containing electron-withdrawing groups. Organometallics 31: 1143-1149
  10. Britovsek GJP, Gibson VC, Wass DF (1999) The search for new-generation olefin polymeriza­tion catalysts: life beyond metallocenes. Angew Chem Int Edit 38: 428-447
  11. Beaufort I, Benvenuti F, Noels AF (2006) Iron(II)–ethylene polymerization catalysts bear­ing 2,6-bis(imino)pyrazine ligands: Part II. Cata­lytic behaviour, homogeneous and heterogeneous insights. J Mol Catal A- Chem 260: 215-220
  12. Thagfi JA, Lafoie GG (2012) Synthesis, charac­terization, and ethylene polymerization studies of chromium, iron, and cobalt complexes con­taining 1,3-Bis(imino)-N-heterocyclic carbene ligands. Organometallics 31: 2463-2469
  13. Englmann T (2011) Homogen und heterogen katalysierte Dimerisierungsreaktionen von Ole finen. PhD thesis, Faculty of Biology, Chemistry and Earth Sciences, University of Bayreuth
  14. Ritter TH, Alt HG (2020) Di(imino)pyridine complexes as catalysts for homogeneous olefin oligomerization reactions.submitted to J J Chem
  15. Britovsek GJP, Bruce M, Gibson VC, Kimber­ley BS, Maddox PJ, Mastroianni S, McTravish SJ, Redshaw C, Solan GA, Stroemberg S, White AJP, Williams DJ (1999) Iron and cobalt ethyl­ene polymerization catalysts bearing 2, 6-bis (imino) pyridyl ligands: synthesis, structures, and polymerization studies. J Am Chem Soc 121: 8728-8740
  16. Zhang Z, Chen S, Zhang X, H Li, Ke Y, Lu Y, Hu Y (2005) A series of novel 2,6-bis(imino)pyridyl iron catalysts: synthesis, characterization and ethylene oligomerization. J Mol Catal A- Chem 230: 1-8
  17. Chen Y, Chen R, Qian C, Dong X, Sun J (2003) Halogen-substituted 2, 6-bis (imino) pyridyl iron and cobalt complexes: highly active catalysts for polymerization and oligomerization of ethylene. Organomet 22: 4312-4321
  18. Schmidt R, Welch MB, Knudsen RD, Gottfried S, Alt HG (2004) N,N,N-Tridentate iron(II) and vanadium(III) complexes: Part II: Catalytic be­havior for the oligomerization and polymeriza­tion of ethene and characterization of the result­ing products. J Mol Catal A- Chem 222: 17-25
  19. Small BL (2003) Tridentate cobalt catalysts for linear dimerization and isomerization of α-olefins. Organometallics 22: 3178-3183
  20. Chen Y, Qian C, Sun J (2003) Fluoro-substituted 2, 6-bis (imino) pyridyl iron and cobalt complex­es: high-activity ethylene oligomerization cata­lysts. Organometallics 22: 1231-1236
  21. Bianchini C, Giambastiani G, Rios IG, Man­tovani G, Meli A, Segarra AM (2006) Ethylene oligomerization, homopolymerization and co­polymerization by iron and cobalt catalysts with 2, 6-(bis-organylimino) pyridyl ligands. Coord Chem Rev 250: 1391-1418