Citation: Xiao-Lin Chen, Jie Gao, Heng Liao, Hai-Yang Gao, Qing Wu. Synthesis, Characterization, and Catalytic Ethylene Oligomerization of Pyridine-imine Palladium Complexes[J]. Chinese Journal of Polymer Science, ;2018, 36(2): 176-184. doi: 10.1007/s10118-018-2052-8 shu

Synthesis, Characterization, and Catalytic Ethylene Oligomerization of Pyridine-imine Palladium Complexes

School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Laboratory of High-performance Polymer Composites, Sun Yat-sen University, Guangzhou 510275, China

Corresponding author: Hai-Yang Gao, gaohy@mail.sysu.edu.cn
Received Date: 28 August 2017
Accepted Date: 28 September 2017
Available Online: 21 November 2017

Two neutral five-membered pyridine-imine palladium complexes with the bulky dibenzhydryl (CH(Ph)₂) substituted aniline were synthesized and fully characterized by nuclear magnetic resonance (NMR) and X-ray crystal diffraction. Well-defined cationic palladium complexes were further obtained by treatment of chloromethylpalladium complexes with sodium tetrakis(3, 5-bis(trifluoromethyl)phenyl)borate (NaBArF) in CH₃CN. Cationic palladium complexes were capable of catalyzing ethylene oligomerization without any cocatalysts. The influences of catalyst structure, reaction temperature, and ethylene pressure on ethylene oligomerization were studied in detail. The introduction of bulky benzhydryl (CH(Ph)₂) on the ortho position of the aniline moiety enhanced catalytic activity, thermal stability of the catalyst, and molecular weight of the obtained products. Highly branched oligomers with molecular weights of 600-800 g/mol and narrow polydispersities (1.03-1.12) were produced.
- Palladium,
- Ethylene,
- Oligomerization,
- Branching
1. [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]. J. Am. Chem. Soc., 1995,117(23):6414-6415. doi: 10.1021/ja00128a054
2. [2]
  Johnson L. K., Mecking S., Brookhart M.. Copolymerization of ethylene and propylene with functionalized vinyl monomers by palladium(Ⅱ) catalysts[J]. J. Am. Chem. Soc., 1996,118(1):267-268. doi: 10.1021/ja953247i
3. [3]
  Small B. L., Brookhart M., Bennett A. M. A.. Highly active iron and cobalt catalysts for the polymerization of ethylene[J]. J. Am. Chem. Soc., 1998,120(16):4049-4050. doi: 10.1021/ja9802100
4. [4]
  Younkin T. R., Connor E. F., Henderson J. I., Friedrich S. K., Grubbs R. H., Bansleben , D. A.. Neutral, single-component nickel(Ⅱ) polyolefin catalysts that tolerate heteroatoms.[J]. Science, 2000,287(5452):460-462. doi: 10.1126/science.287.5452.460
5. [5]
  Drent E., Dijk R. V., Ginkel R. V., Oort B., Pugh R. I.. Palladium catalysed copolymerisation of ethene with alkylacrylates: polar comonomer built into the linear polymer chain[J]. Chem. Commun., 2002:744-745.
6. [6]
  Mu H. L., Pan L., Song D. P., Li Y. S.. Neutral nickel catalysts for olefin homo-and copolymerization: relationships between catalyst structures and catalytic properties[J]. Chem. Rev., 2015,115(22):12091-12137. doi: 10.1021/cr500370f
7. [7]
  Guo L. H., Dai S. Y., Sui X. L., Chen C. L.. Palladium and nickel catalyzed chain walking olefin polymerization and copolymerization[J]. ACS Catal., 2016,6(1):428-441. doi: 10.1021/acscatal.5b02426
8. [8]
  Guo L. H., Chen C. L.. (α-Diimine) palladium catalyzed ethylene polymerization and (co)polymerization with polar comonomers[J]. Sci. China Chem., 2015,58(11):1663-1673. doi: 10.1007/s11426-015-5433-7
9. [9]
  Guo L. H., Liu W. J., Chen C. L.. Late transition metal catalyzed α-olefin polymerization and copolymerization with polar monomers[J]. Mater. Chem. Front., 2017. doi: 10.1039/C7QM00321H
10. [10]
  Gao H. Y., Liu F. S., Hu H. B., Zhu F. M., Wu Q.. Synthesis of bimodal polyethylene with unsymmetrical α-diimine nickel complexes: influence of ligand backbone and unsym-substituted aniline moiety[J]. Chinese J. Polym. Sci., 2013,31(4):563-573. doi: 10.1007/s10118-013-1251-6
11. [11]
  Gao H. Y., Pei L. X., Li Y. F., Zhang J. K., Wu Q.. Vinyl polymerization of norbornene with nickel catalysts bearing[J]. J. Mol. Catal. A-Chem., 2008,280(1-2):81-86. doi: 10.1016/j.molcata.2007.10.033
12. [12]
  Gao H. Y., Pei L. X., Song K. M., Wu Q.. Styrene polymerization with novel anilido-imino nickel complexes/MAO catalytic system: catalytic behavior, microstructure of polystyrene and polymerization mechanism[J]. Eur. Polym. J., 2007,43(3):908-914. doi: 10.1016/j.eurpolymj.2006.11.026
13. [13]
  Li Y. F., Wang L. Y., Gao H. Y., Zhu F. M., Wu Q.. Novel nickel(Ⅱ) complexes chelating β-diketiminate ligands: synthesis and simultaneous polymerization and oligomerization of ethylene[J]. Appl. Organomet. Chem., 2006,20(7):436-442. doi: 10.1002/(ISSN)1099-0739
14. [14]
  Gao H. Y., Zhang J. K., Chen Y., Zhu F. M., Wu Q.. Vinyl-polymerization of norbornene with novel anilido-imino nickel complexes/methylaluminoxane: abnormal influence of polymerization temperature on molecular weight of polynorbornenes.[J]. J. Mol. Catal. A-Chem., 2005,240(1-2):178-185.
15. [15]
  Zhong L., Li G. L., Liang G. D., Gao H. Y., Wu Q.. 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[J]. Macromolecules, 2017,50(7):2675-2682. doi: 10.1021/acs.macromol.7b00121
16. [16]
  Zhong S. H., Tan Y. X., Zhong L., Gao J., Liao H., Jiang L., Gao H. Y., Wu Q.. Precision synthesis of ethylene and polar monomer copolymers by palladium-catalyzed living coordination copolymerization[J]. Macromolecules, 2017,50(15):5661-5669. doi: 10.1021/acs.macromol.7b01132
17. [17]
  Liao H., Zhong L., Xiao Z. F., Zheng T., Gao H. Y., Wu Q.. α-Diamine nickel catalysts with nonplanar chelate rings for ethylene polymerization[J]. Chem. Eur. J., 2016,22(39):14048-14055. doi: 10.1002/chem.201602467
18. [18]
  Hu H. B., Chen D. R., Gao H. Y., Zhong L., Wu Q.. Amine-imine palladium catalysts for living polymerization of ethylene and copolymerization of ethylene with methyl acrylate: incorporation of acrylate units into the main chain and branch end[J]. Polym. Chem., 2016,7:529-537. doi: 10.1039/C5PY01743B
19. [19]
  Hu H. B., Gao H. Y., Chen D. R., Li G. L., Tan Y. X., Liang G. D., Zhu F. M., Wu Q.. Ligand-directed regioselectivity in amine-imine nickel-catalyzed 1-hexene polymerization[J]. ACS Catal., 2015,5(1):122-128. doi: 10.1021/cs501081a
20. [20]
  Liu J., Chen D. R., Wu H., Xiao Z. F., Gao H. Y., Zhu F. M., Wu Q.. Polymerization of α-olefins using a camphyl α-diimine nickel catalyst at elevated temperature[J]. Macromolecules, 2014,47(10):3325-3331. doi: 10.1021/ma5004634
21. [21]
  Hu H. B., Zhang L., Gao H. Y., Zhu F. M., Wu. Q.. Design of thermally stable amine-imine nickel catalyst precursors for living polymerization of ethylene: effect of ligand substituents on catalytic behavior and polymer properties[J]. Chem. Eur. J., 2014,20(11):3225-3233. doi: 10.1002/chem.201303813
22. [22]
  Gao H. Y., Liu Y., Li G. L., Xiao Z. F., Liang G. D., Wu Q.. Catalytic synthesis of polyethylene-block-polynorbornene copolymers using a living polymerization nickel catalyst[J]. Polym. Chem., 2014,5:6012-6018. doi: 10.1039/C4PY00701H
23. [23]
  Gao H. Y., Li G. L., Hu Z. L., Xiao Z. F., Liang G. D., Wu. Q.. Synthesis of amphiphilic polyethylene-b-poly(l-glutamate) block copolymers with vastly different solubilities and their stimuli-responsive polymeric micelles in aqueous solution[J]. Polymer, 2014,55:4593-4600. doi: 10.1016/j.polymer.2014.07.019
24. [24]
  Deng J. A., Gao H. Y., Zhu F. M., Wu Q.. Synthesis and structure of imine-n-heterocyclic carbene palladium complexes and their catalytic behavior in norbornene polymerization[J]. Organometallics, 2013,32(16):4507-4515. doi: 10.1021/om400268y
25. [25]
  Gao H. Y., Tang Y., Hu H. B., Guan Q. R., Shi X. B., Zhu F. M., Wu Q.. Synthesis of amphiphilic copolymers with a dendritic polyethylene core and poly(ethylene oxide) arms and their self-assembled nanostructures[J]. Polym. Chem., 2013,4:1107-1114. doi: 10.1039/C2PY20831H
26. [26]
  Gao H. Y., Hu Z. L., Guan Q. R., Liu Y., Zhu F. M., Wu Q.. Synthesis and thermoreversible gelation of coil-helical polyethylene-block-poly(gamma-benzyl-L-glutamate) diblock copolymer[J]. Polymer, 2013,54:4923-4929. doi: 10.1016/j.polymer.2013.06.055
27. [27]
  Gao H. Y., Hu H. B., Zhu F. M., Wu Q.. A thermally robust amine-imine nickel catalyst precursor for living polymerization of ethylene above room temperature[J]. Chem. Commun., 2012,48:3312-3314. doi: 10.1039/c2cc17154f
28. [28]
  Azoulay J. D., Gao H. Y., Koretz Z. A., Kehr G., Erker G., Shimizu F., Galland G. B., Bazan G. C.. Propylene polymerization with alpha-keto-beta-diimine initiators proceeds via enantiomorphic site control[J]. Macromolecules, 2012,45:4487-4493. doi: 10.1021/ma300504j
29. [29]
  Shi X. B., Zhao Y., Gao H. Y., Zhang L., Zhu F. M., Wu Q.. Synthesis of hyperbranched polyethylene amphiphiles by chain walking polymerization in tandem with RAFT polymerization and supramolecular self-assembly vesicles[J]. Macromol. Rapid Commun., 2012,33(5):374-379. doi: 10.1002/marc.201100825
30. [30]
  Gao H. Y., Liu X. F., Tang Y., Pan J., Wu Q.. Living/controlled polymerization of 4-methyl-1-pentene with α-diimine nickel-diethylaluminium chloride: effect of alkylaluminium cocatalysts[J]. Polym. Chem., 2011,2:1398-1403. doi: 10.1039/c1py00052g
31. [31]
  Gao H. Y., Pan J., Guo L. H., Xiao D. J., Wu Q.. Polymerization of 4-methyl-1-pentene catalyzed by-diimine nickel catalysts: living/controlled behavior, branch structure, and mechanism[J]. Polymer, 2011,52:130-137. doi: 10.1016/j.polymer.2010.11.008
32. [32]
  Guo L. H., Gao H. Y., Wu Q.. Complex branched polyolefin generated from quasi-living polymerization of 4-methyl-1-pentene catalyzed by α-diimine palladium catalyst[J]. Macromol. Chem. Phys., 2011,212(18):2029-2035. doi: 10.1002/macp.v212.18
33. [33]
  Guo L. H., Gao H. Y., Guan Q. R., Hu H. B., Deng J. A., Liu J., Liu S. F., Wu Q.. Substituent effects of the backbone in α-diimine palladium catalysts on homo-and copolymerization of ethylene with methyl acrylate[J]. Organometallics, 2012,31(17):6054-6062. doi: 10.1021/om300380b
34. [34]
  Liu F. S., Hu H. B., Xu Y., Guo L. H., Zai S. B., Song K. M., Gao H. Y., Zhang L., Zhu F. M., Wu Q.. Thermostable α-diimine nickel(Ⅱ) catalyst for ethylene polymerization: effects of the substituted backbone structure on catalytic properties and branching structure of polyethylene[J]. Macromolecules, 2009,42(20):7789-7796. doi: 10.1021/ma9013466
35. [35]
  Huang Z. F., Song K. M., Liu F. S., Long J. M., Hu H., Gao H. Y., Wu Q.. Synthesis and characterization of a series of 2-aminopyridine nickel(Ⅱ) complexes and their catalytic properties toward ethylene polymerization[J]. J. Polym. Sci., Part A: Polym. Chem., 2008,46(5):1618-1628. doi: 10.1002/(ISSN)1099-0518
36. [36]
  Zai S. B., Gao H. Y., Huang Z. F., Hu H. B., Wu H., Wu Q.. Substituent effects of pyridine-amine nickel catalyst precursors on ethylene polymerization[J]. ACS Catal., 2012,2(3):433-440. doi: 10.1021/cs200593c
37. [37]
  Zhao Y., Gao H. Y., Zhang L., Zhu F. M., Wu Q.. Thermo-and pH-sensitive polyethylene-based diblock and triblock copolymers: synthesis and self-assembly in aqueous solution[J]. J. Mater. Chem., 2012,22:5737-5745. doi: 10.1039/c2jm16197d
38. [38]
  Zai S. B., Liu F. S., Gao H. Y., Li C., Zhou G. Y., Cheng S., Guo L. H., Zhang L., Zhu F. M., Wu Q.. Longstanding living polymerization of ethylene: substituent effect on bridging carbon of 2-pyridinemethanamine nickel catalysts[J]. Chem. Commun., 2010,46:4321-4323. doi: 10.1039/c000176g
39. [39]
  Guo L. H., Gao H. Y., Zhang L., Zhu F. M., 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[J]. Organometallics, 2010,29(9):2118-2125. doi: 10.1021/om9010356
40. [40]
  Bianchini C., Giambastiani G., Luconi L., Meli A.. Olefin oligomerization, homopolymerization and copolymerization by late transition metals supported by (imino)pyridine ligands[J]. Coordin. Chem. Rev., 2010,254(5-6):431-455. doi: 10.1016/j.ccr.2009.07.013
41. [41]
  Tang X. B., Sun W. H., Gao T. L., Hou J. X., Chen J. T., Chen W.. Nickel(Ⅱ) complexes bearing 2-ethylcarboxylate-6-iminopyridyl ligands: synthesis, structures and their catalytic behavior for ethylene oligomerization and polymerization[J]. J. Organomet. Chem., 2005,690(6):1570-1580. doi: 10.1016/j.jorganchem.2004.12.027
42. [42]
  Laine T. V., Piironen U., Lappalainen K., Klinga M., Aitola L. M.. Nickel(Ⅱ) complexes bearing 2-ethylcarboxylate-6-iminopyridyl ligands: synthesis, structures and their catalytic behavior for ethylene oligomerization and polymerization[J]. J. Organomet. Chem., 2000,606(2):112-124. doi: 10.1016/S0022-328X(00)00291-6
43. [43]
  Dai S. Y., Sui X. L., Chen C. L.. Synthesis of high molecular weight polyethylene using iminopyridyl nickel catalysts[J]. Chem. Commun., 2016,52:9113-9116. doi: 10.1039/C6CC00457A
44. [44]
  Dai S. Y., Chen C. L.. Direct synthesis of functionalized high-molecular-weight polyethylene by copolymerization of ethylene with polar monomers[J]. Angew. Chem. Int. Ed., 2016,55(42):13281-13285. doi: 10.1002/anie.201607152
45. [45]
  Dai S. Y., Zhou S. X., Zhang W., Chen C. L.. Systematic investigations of ligand steric effects on α-diimine palladium catalyzed olefin polymerization and copolymerization[J]. Macromolecules, 2016,49(23):8855-8862. doi: 10.1021/acs.macromol.6b02104
46. [46]
  Sui X. L., Hong C. W., Pang W. M., Chen C. L.. Unsymmetrical α-diimine palladium catalysts and their properties in olefin (co)polymerization[J]. Mater. Chem. Front., 2017,1:967-972. doi: 10.1039/C6QM00235H
47. [47]
  Guo L. H., Zou C., Dai S. Y., Chen C. L.. Direct synthesis of branched carboxylic acid functionalized poly(1-octene) by α-diimine palladium catalysts[J]. Polymers, 2017,9(4)122. doi: 10.3390/polym9040122
48. [48]
  Hu X. H., Dai S. Y., Chen C. L.. Ethylene polymerization by salicylaldimine nickel(Ⅱ) complexes containing a dibenzhydryl moiety[J]. Dalton Trans., 2016,45:1496-1503. doi: 10.1039/C5DT04408A
49. [49]
  Rhinehart J. L., Brown L. A., Long B. K.. A robust Ni(Ⅱ) α-diimine catalyst for high temperature ethylene polymerization[J]. J. Am. Chem. Soc., 2013,136:16316-16319.
50. [50]
  Dai S. Y., Sui X. L., Chen C. L.. Highly robust palladium(Ⅱ) α-diimine catalysts for slow-chain-walking polymerization of ethylene and copolymerization with methyl acrylate[J]. Angew. Chem. Int. Ed., 2015,54(34):9948-9953. doi: 10.1002/anie.201503708
51. [51]
  Sun W. H., Song S. J., Li B. X., Redshaw C., Hao X., Li Y. S., Wang F. S.. Ethylene polymerization by 2-iminopyridylnickel halide complexes: synthesis, characterization and catalytic influence of the benzhydryl group[J]. Dalton Trans., 2012,41:11999-12010. doi: 10.1039/c2dt30989k
52. [52]
  Meneghetti S. P., Lutz P. J., Kress J.. Oligomerization of olefins catalyzed by new cationic palladium(Ⅱ) complexes containing an unsymmetrical α-diimine ligand[J]. Organometallics, 1999,18(15):2734-2737. doi: 10.1021/om990165k
53. [53]
  Nyamato G. S., Ojwach S. O., Akerman M. P.. Potential hemilabile (imino)pyridine palladium(Ⅱ) complexes as selective ethylene dimerization catalysts: an experimental and theoretical approach[J]. Organometallics, 2015,34(23):5647-5657. doi: 10.1021/acs.organomet.5b00860
54. [54]
  Bezier D., Daugulis O., Brookhart M.. Oligomerization of ethylene using a diphosphine palladium catalyst[J]. Organometallics, 2017,36(2):443-447. doi: 10.1021/acs.organomet.6b00850
55. [55]
  Stephenson C. J., Mcinnis J. P., Chen C. L., Weberski M. P., Motta A., Delferro M., Marks T. J.. Ni(Ⅱ) phenoxyiminato olefin polymerization catalysis: striking coordinative modulation of hyperbranched polymer microstructure and stability by a proximate sulfonyl group[J]. ACS Catal., 2014,4(3):999-1003. doi: 10.1021/cs500114b
56. [56]
  Wiedemann T., Voit G., Tchernook A., Roesel P., Schnetmann I. G., Mecking S.. Monofunctional hyperbranched ethylene oligomers[J]. J. Am. Chem. Soc., 2014,136(5):2078-2085. doi: 10.1021/ja411945n
57. [57]
  Jie S. Y., Zhang D. H., Zhang T. Z., Sun W. H., Chen J. T., Ren Q., Liu D. B., Zheng G., Chen W. J.. Bridged bispyridinylimino dinickel(Ⅱ) complexes: syntheses, characterization, ethylene oligomerization and polymerization[J]. Organomet. Chem., 2005,690(7):1739-1749. doi: 10.1016/j.jorganchem.2005.01.029
58. [58]
  Xiang P., Ye Z. B., Subramanian R.. Synthesis and characterization of low-and medium-molecular-weight hyperbranched polyethylenes by chain walking ethylene polymerization with Pd-diimine catalysts[J]. Polymer, 2011,52(22):5027-5039. doi: 10.1016/j.polymer.2011.09.010
59. [59]
  Ray S., Rao P. V. C., Choudary N. V. V.. Poly-α-olefin-based synthetic lubricants: a short review on various synthetic routes[J]. Lubr. Sci., 2012,24:23-44. doi: 10.1002/ls.v24.1
1. [1]
  Hailong He , Wenbing Wang , Wenmin Pang , Chen Zou , Dan Peng . Double stimulus-responsive palladium catalysts for ethylene polymerization and copolymerization. Chinese Chemical Letters, 2024, 35(7): 109534-. doi: 10.1016/j.cclet.2024.109534
2. [2]
  Gongcheng Ma , Qihang Ding , Yuding Zhang , Yue Wang , Jingjing Xiang , Mingle Li , Qi Zhao , Saipeng Huang , Ping Gong , Jong Seung Kim . Palladium-free chemoselective probe for in vivo fluorescence imaging of carbon monoxide. Chinese Chemical Letters, 2024, 35(9): 109293-. doi: 10.1016/j.cclet.2023.109293
3. [3]
  Junying Zhang , Ruochen Li , Haihua Wang , Wenbing Kang , Xing-Dong Xu . Photo-induced tunable luminescence from an aggregated amphiphilic ethylene-pyrene derivative in aqueous media. Chinese Chemical Letters, 2024, 35(6): 109216-. doi: 10.1016/j.cclet.2023.109216
4. [4]
  Xiaoxiao Huang , Zhi-Long He , Yangpeng Chen , Lei Li , Zhenyu Yang , Chunyang Zhai , Mingshan Zhu . Novel P-doping-tuned Pd nanoflowers/S,N-GQDs photo-electrocatalyst for high-efficient ethylene glycol oxidation. Chinese Chemical Letters, 2024, 35(6): 109271-. doi: 10.1016/j.cclet.2023.109271
5. [5]
  Ke Zhang , Sheng Zuo , Pengyuan You , Tong Ru , Fen-Er Chen . Palladium-catalyzed stereoselective decarboxylative [4 + 2] cyclization of 2-methylidenetrimethylene carbonates with pyrrolidone-derived enones: Straightforward access to chiral tetrahydropyran-fused spiro-pyrrolidine-2,3-diones. Chinese Chemical Letters, 2024, 35(6): 109157-. doi: 10.1016/j.cclet.2023.109157

Get Citation

PDF

XML

Metrics

PDF Downloads(0)
Abstract views(658)
HTML views(48)

通讯作者: 陈斌, bchen63@163.com

1.
沈阳化工大学材料科学与工程学院沈阳 110142