Highly branched unsaturated polyethylenes achievable using strained imino-cyclopenta[b]pyridyl-nickel precatalysts | |
Department | OSSO国家重点实验室 |
Zhang, Youfu1,2; Huang, Chuanbing2,3; Wang, Xinxin2,3; Qaiser Mahmood2,3; Hao, Xiang2; Hu XQ(胡信全)1; Guo, Cun-Yue3; Gregory A. Solan2,4; Sun WH(孙文华)2,3,5; Hu XQ(胡信全); Sun WH(孙文华) | |
2017 | |
Source Publication | Polymer Chemistry |
ISSN | 1759-9954 |
Volume | 8Issue:6Pages:995-1005 |
Abstract | A new family of strained imino-cyclopenta[b]pyridines, 7-(ArN)-6-Me2C8H5N (Ar = 2,6-Me2Ph (L1), 2,6-Et2Ph (L2), 2,4,6-Me3Ph (L3), 2,6-Et2-4-MePh (L4), 2,6-i-Pr2Ph (L5)), have been synthesized in reasonable yield by a sequence of reactions from 2-chloro-cyclopenta[b]pyridin-7-one. Treatment of L1 and L3 with NiCl2·6H2O generates mononuclear bis-ligated [7-(ArN)-6-Me2C8H5N]2NiCl2 (Ar = 2,6-Me2Ph (Ni1), 2,4,6-Me3Ph (Ni3)), while with L2 and L4, the chloride-bridged binuclear complexes [7-(ArN)-6-Me2C8H5N]2Ni2(μ-Cl)2Cl2 (Ar = 2,6-Et2Ph (Ni2), 2,6-Et2-4-MePh (Ni4)), have been isolated; no apparent reaction occurred with L5. On activation with either MAO or MMAO, Ni1–Ni4 exhibited high activities towards ethylene polymerization with Ni3 the most active (5.02 × 106 g PE per mol Ni per h at 20 °C); rapid regeneration of the active species (3096–5478 h−1 at 20 °C) is a feature of their catalytic performance. A detailed microstructural analysis of the polyethylenes reveals the presence of vinyl and higher levels of internal vinylene groups indicative of high rates of chain isomerization, e.g., the ratio of (–CHCH–) to (H2CCH–) groups is 2.2:1 using Ni3/MAO at 60 °C. Agostic interactions involving γ-, δ- and higher-hydrogens are inferred in addition to β-hydrogen elimination to account for the vinylene groups and the longer chain alkyl branches. The molecular structures of Ni1 and Ni2·2MeOH are also reported. |
Subject Area | 物理化学与绿色催化 |
DOI | 10.1039/c6py02089e |
Funding Organization | the National Natural Science Foundation of China (No. U1362204;21473160;21374123;51373176);the Chinese Academy of Sciences for a Visiting Scientist Fellowship |
Indexed By | SCI |
If | 5.375 |
Language | 英语 |
compositor | 第五作者单位 |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.licp.cn/handle/362003/21623 |
Collection | 羰基合成与选择氧化国家重点实验室(OSSO) |
Corresponding Author | Guo, Cun-Yue; Gregory A. Solan; Hu XQ(胡信全); Sun WH(孙文华) |
Affiliation | 1.College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China 2.Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China 3.School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China 4.Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK 5.State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China |
Recommended Citation GB/T 7714 | Zhang, Youfu,Huang, Chuanbing,Wang, Xinxin,et al. Highly branched unsaturated polyethylenes achievable using strained imino-cyclopenta[b]pyridyl-nickel precatalysts[J]. Polymer Chemistry,2017,8(6):995-1005. |
APA | Zhang, Youfu.,Huang, Chuanbing.,Wang, Xinxin.,Qaiser Mahmood.,Hao, Xiang.,...&孙文华.(2017).Highly branched unsaturated polyethylenes achievable using strained imino-cyclopenta[b]pyridyl-nickel precatalysts.Polymer Chemistry,8(6),995-1005. |
MLA | Zhang, Youfu,et al."Highly branched unsaturated polyethylenes achievable using strained imino-cyclopenta[b]pyridyl-nickel precatalysts".Polymer Chemistry 8.6(2017):995-1005. |
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