Synthesis and olefin homo- and copolymerization behavior of new vanadium complexes bearing [OSSO]-type ligands

Abstract

Novel vanadium complexes bearing [OSSO]-type ligands having two phenolato units linked through the -CH 2 S(CH 2 ) 4 SCH 2 -(1V) or -CH 2 S(CH 2 ) 2-SCH 2 -(2V) bridge are synthesized with good yields by reacting a deprotonated ligand with VCl 4 . They are then used in ethylene (co)polymerization after activation with EtAlCl 2 and Et 2 AlCl. In the presence of EtAlCl 2 , both complexes promote ethylene polymerization with very high activities, over 4 9 10 7 g/(mol h), leading to PEs with high molecular weight and narrow molecular weight distribution. The prepared complexes exhibit lower activity for ethylene/1-octene copolymerization. It is also revealed that the catalyst based on the -CH 2 S(CH 2 ) 4 SCH 2 -bridged complex shows both higher activity and higher comonomer incorporation ability than the catalyst based on the -CH 2 S(CH 2 ) 2 SCH 2 -bridged complex. Upon activation with Al(iBu) 3 /Ph 3 CB(C 6 F 5 ) 4 , complex 2V produces stereo-and regioirregular poly(1-octene), while 1V gives the isotactically enriched product.

Progress in vanadium complex catalysts and their catalytic behavior toward copolymerization of ethylene with α-olefins

“…, 得到的 共聚物中1-辛烯结构单元含量分别为5.4%(mol)和5.3% (mol) [51] . 含O^S^S^O四齿配体的钒(IV)配合物40催化 乙烯与1-辛烯共聚催化活性高于含O^N^N^O四齿配体 的钒(IV)配合物38和39 [52] . 在相同聚合条件下(Al/V = 600,…”