喹啉醛亚胺钴配合物催化丁二烯顺式-1,4选择性聚合

合成和表征了一系列以NN]双齿喹啉醛亚胺为配体的二氯化钴配合物（1a~6a）。 以X射线单晶衍射技术分析了配合物2a、3a和4a的分子结构。 配合物2a和3a以单核四配位（2个氮原子和2个氯原子）的形式结晶,而配合物4a由于取代基空间位阻小,则以双核的形式结晶。 在倍半乙基氯化铝（EASC）的活化下,该催化体系引发丁二烯单体聚合,得到顺式-1,4结构含量高达98%的聚丁二烯。 催化剂催化活性随配体上取代基吸电子能力的增加而提高,但随取代基空间位阻的增加而降低。 所合成的聚丁二烯具有高相对分子质量(Mn约为2.0×105)和窄的相对分子质量分布（Mw/Mn＜2.7）。

Cis-1,4 Selective Polymerization of 1,3-Butadiene Catalyzed by Cobalt Complexes Bearing 2-(1-Aryliminomethylene)quinolines

A series of cobalt(Ⅱ) complexes bearing 2-(1-aryliminomethylene)quinolines was synthesized and characterized. The structures of complexes 2a, 3a and 4a were further analyzed by X-ray crystallography. Complexes 2a and 3a crystallize in the form of mononuclear four-coordination mode(two nitrogen and two chlorine atoms), whereas complex 4a crystallizes as a centrosymmetric binuclear mode due to the less steric hindrance of the substituent on the ligand. Upon activation with ethylaluminum sesquichloride(EASC), polybutadienes with cis-1,4 content up to 98% could be produced using these complex as catalyst. Catalytic activity increases with the electronic effect of the substituent enhancing, while it decreases with the increase of the steric hindrance. The polybutadienes obtained by using 2-(1-aryliminomethylene)quinolines]cobalt/EASC catalyst have relatively high molecular mass(Mn ~2.0×105) and relatively narrow molecular mass distributions(Mw/Mn＜2.7).