Determination of the catalytic active species in the polymerization of propylene by titanium benzamidinate complexes
Determination of the catalytic active species in the polymerization of propylene by titanium benzamidinate complexes
复制标题
苯甲脒钛配合物聚合丙烯中催化活性物质的测定
DOI：
10.1021/om0602198
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发表时间：
2006
期刊：
影响因子：
2.8
通讯作者：
M. Eisen
中科院分区：
文献类型：
--
作者：
Victoria V. Volkis;A. Lisovskii;B. Tumanskii;M. Shuster;M. Eisen
单体双钛催化剂的催化行为（苯甲脒基）[η-C 6 H 5 -C（NSiMe 3）2 ] 2 TiCl 2（1），二聚钛单（苯甲脒基）{[η-C 6 H 5 -C（NSiMe 3）2 ]TiCl 3 ]} 2（2），单体钛单苯甲脒配合物η-C6 H5-C比较了甲基铝氧烷（MAO）活化的（NSiMe 3）2 ]TiCl 3 ]·THF（3）在乙烯和丙烯聚合中的催化活性。尽管结构和对称性的差异，所有的预催化剂的活动被发现是一样的，这表明重排向类似的活性物种是可操作的聚合过程中，无论起始材料。为了阐明从不同的苯甲脒钛络合物形成这种活性物质的机理途径和铝助催化剂在活化过程中的作用，合成了相应的苯甲脒铝二氯和二甲基络合物，并与钛络合物进行了比较。使用NMR和ESR光谱，[60]富勒烯捕获实验和MALDI-TOF质谱监测不同活性位点的形成。本出版物中介绍并讨论了不同苯甲脒钛络合物的结果，以及它们与MAO的活化反应及其在加入烯烃后的命运的建议机理途径。此外，公开了聚合物的粘弹性和流变机械性能。
The catalytic behavior of the monomeric titanium bis(benzamidinate) [η-C 6 H 5 -C(NSiMe 3 ) 2 ] 2 TiCl 2 (1), the dimeric titanium mono(benzamidinate) {[η-C 6 H 5 -C(NSiMe 3 ) 2 ]TiCl 3 ]} 2 (2), and the monomeric titanium mono(benzamidinate) complex η-C 6 H 5 -C(NSiMe 3 ) 2 ]TiCl 3 ]·THF (3) activated by methylalumoxane (MAO) has been compared in the polymerization of ethylene and propylene. Despite structural and symmetrical differences, the activities of all precatalysts were found to be alike, indicating that rearrangements toward similar active species are operative during the polymerization regardless of the starting materials. To shed some light on the mechanistic pathways for the formation of such active species from the different titanium benzamidinate complexes and on the role of the aluminum cocatalyst in the activation process, corresponding aluminum benzamidinate dichloro and dimethyl complexes were synthesized and compared to the titanium complexes. The formation of the different active sites was monitored using NMR and ESR spectroscopy, trapping experiments with [60]fullerene, and MALDI-TOF mass spectroscopy. The results obtained for the different benzamidinate titanium complexes and proposed mechanistic pathways for their activation reactions with MAO and their fate after the addition of the olefins are presented and discussed in this publication. In addition, viscoelastic and rheological mechanical properties of the polymers are disclosed.