Synthesis and characterization of novel neutral nickel complexes bearing fluorinated salicylaldiminato ligands and their catalytic behavior for vinylic polymerization of norbornene |
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| Authors: | Dong‐Po Song Yan‐Guo Li Ran Lu Ning‐Hai Hu Yue‐sheng Li |
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| Institution: | 1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China;2. College of Chemistry, Jilin University, Changchun 130023, People's Republic of China |
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| Abstract: | A series of salicylaldimine‐based neutral Ni(II) complexes (3a–j) ArN = CH(C6H4O)]Ni(PPh3)Ph 3a, Ar = C6H5; 3b, Ar = C6H4F(o); 3c, Ar = C6H4F(m); 3d, Ar = C6H4F(p); 3e, Ar = C6H3F2(2,4); 3f, Ar = C6H3F2(2,5); 3g, Ar = C6H3F2(2,6); 3h, Ar = C6H3F2(3,5); 3i, Ar = C6H2F3(3,4,5); 3j, Ar = C6F5] have been synthesized in good yield, and the structures of complexes 3a and 3i have been confirmed by X‐ray crystallographic analysis. Using modified methylaluminoxane as a cocatalyst, these neutral Ni(II) complexes exhibited high catalytic activities for the vinylic polymerization of norbornene. It was observed that the strong electron‐withdrawing effect of the fluorinated salicylaldiminato ligand was able to significantly increase the catalyst activity for vinylic polymerization of norbornenes. In addition, catalyst activity, polymer yield and polymer molecular weight can also be controlled over a wide range by the variation of reaction parameters such as Al:Ni ratio, norbornene:catalyst ratio, monomer concentration, polymerization temperature and time. Copyright © 2008 John Wiley & Sons, Ltd. |
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| Keywords: | neutral nickel complexes catalyst electronic effect norbornene addition polymerization |
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