Influence of imine-carbon substituent in 6-bromo-2-iminopyridine-based cobalt(II) complexes on 1,3-butadiene polymerization
Influence of imine-carbon substituent in 6-bromo-2-iminopyridine-based cobalt(II) complexes on 1,3-butadiene polymerization
复制标题
6-溴-2-亚氨基吡啶基钴(II)配合物中亚胺-碳取代基对1,3-丁二烯聚合的影响
DOI：
10.1002/pi.5854
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发表时间：
2019
影响因子：
3.2
通讯作者：
Zhang Xuequan
中科院分区：
文献类型：
--
作者：
Wang Feng;Liu Heng;Hu Yanming;Zhang Xuequan
合成了含不同亚胺-碳取代基(CO1-CO7)的6-溴-2-亚氨基吡啶钴(II)配合物，并将其用于1，3-丁二烯聚合。通过傅里叶变换红外光谱和元素分析对化合物进行了表征，并用单晶X-射线衍射仪对化合物Co1和Co3进行了表征，证明它们分别具有扭曲的三角双锥和四面体构型。在甲基铝氧烷的活化下，这些化合物表现出较高的顺式-1，4选择性，其活性高度依赖于配体亚胺-碳位上的取代基。在聚合体系中加入PPh_3可以提高催化活性，同时使选择性由顺-1，4变为顺-1，2。在此基础上，提出了一种可能的调控选择性和活性的机理。2019中国化学工业学会
6‐Bromo‐2‐iminopyridine cobalt(II) complexes bearing different imine‐carbonsubstituents (Co1–Co7) were synthesized and subsequently employed for 1,3‐butadiene polymerization. All the complexes were identified using Fourier transform infrared spectra and elemental analysis, and complexesCo1andCo3were further characterized using single‐crystal X‐ray diffraction analysis, demonstrating they adopted distorted trigonal bipyramidal and tetrahedral geometries, respectively. Activated by methylaluminoxane, these complexes exhibited highcis‐1,4 selectivity, and the activity was highly dependent on the substituent at the imine‐carbonposition of the ligand. Addition of PPh3to the polymerization systems could enhance the catalytic activity and simultaneously switched the selectivity fromcis‐1,4 tocis‐1,2 manner. On the basis of the obtained results, a plausible mechanism involving the regulation of selectivity and activity is proposed. © 2019 Society of Chemical Industry