- 1,3-Butadiene Polymerizations Catalyzed by Cobalt and Iron Dichloride Complexes Bearing Pyrazolylimine Ligands
- 点击次数：
- 影响因子：3.6
- DOI码：10.1007/s10118-019-2198-z
- 所属单位：中国科学院长春应用化学研究所
- 发表刊物：Chinese J. Polym. Sci.
- 关键字：Late transition metal; Cobalt(II) complexes; Iron(II)complexes; Stereoselective polymerization; Polybutadiene
- 摘要：A series of pyrazolylimine ligated Co(II) and Fe(II) complexes with general formula of (PhC＝N(C6H3(R1)2-2,6)(C3HN2 (R2)2-3,5)MtCl2 (R1 = Me, R2 = H, Mt = Co (1a), Fe (2a); R1 = Me, R2 = Me, Mt = Co (1b), Fe (2b); R1 = iPr, R2 = H, Mt = Co (1c), Fe (2c); R1 = iPr, R2 = Me, Mt = Co (1d), Fe (2d); R1 = iPr, R2 = Ph, Mt = Co (1e), Fe (2e)) were synthesized and thoroughly characterized. Determined by single crystal X-ray diffraction, complexes 1b and 2b revealed dimeric structures, in which distorted trigonal bipyramid geometries were adopted for each metal centers. In the presence of ethylaluminum sesquichloride (EASC), all the cobalt complexes displayed high activities in 1,3-butadiene polymerization, affording polybutadienes with predominant cis-1,4 contents (up to 97.0%). Influences of ligand structure and polymerization parameters on catalytic performance were investigated systematically. For pyrazolylimine iron(II) dichloride complexes, the catalytic activities and microstructures of the resultant polybutadienes were highly dependent on ligand structures and polymerization conditions. For complex 2a, changing cocatalyst from trialkyl aluminums to methyl aluminoxane (MAO) led to an shift of selectivity from high cis-1,4- to trans-1,4-/1,2- manner. Being activated by MAO, complexes 2a and 2b gave trans-1,4-/1,2- binary polybutadienes, while complexes 2c, 2d, and 2e afforded cis-1,4- enriched polymers.
- 论文类型：期刊论文
- 学科门类：理学
- 一级学科：化学
- 文献类型：J
- 卷号：37
- 页面范围：462-470
- 是否译文：否
- 发表时间：2018-11-26
- 收录刊物：SCI
