Titanium isopropoxide complexes of a series of sterically demanding aryloxo based [N2O2]2− ligands as precatalysts for ethylene polymerization
作者:Manas K. Panda、Sukhdeep Kaur、Annapureddy Rajasekhar Reddy、Mobin M. Shaikh、Ray J. Butcher、Virendrakumar Gupta、Prasenjit Ghosh
DOI:10.1039/c0dt00407c
日期:——
Several titanium isopropoxide complexes [N,Nâ²-bis(2-oxo-3-R1-5-R2-phenylmethyl)-N,Nâ²-bis(methylene-p-R3-C6H4)-ethylenediamine]Ti(OiPr)2 [R1 = t-Bu, R2 = Me, R3 = H (1b); R1 = R2 = t-Bu, R3 = H, (2b); R1 = R2 = Cl, R3 = H, (3b), R1 = t-Bu, R2 = Me, R3 = Cl (4b); R1 = R2 = t-Bu, R3 = Cl, (5b); R1 = R2 = R3 = Cl, (6b)] supported over sterically demanding aryloxy based [N2O2]H2 ligands have been designed as precatalysts for the ethylene polymerization. Specifically, the 1bâ6b complexes, when treated with methylaluminoxane (MAO) under 88 ± 0.5 psi of ethylene at 30 °C for 3 h, produced polyethylene polymers of high molecular weight (Mw = ca. 7.2â8.3 à 105 g molâ1) having broad molecular weight distribution (PDI = ca. 13.1â14.6). The 1bâ6b complexes were conveniently synthesized from the direct reaction of the [N2O2]H2 ligands, 1aâ6a, with Ti(OiPr)4 in 69â86% yield.
几种异丙醇钛络合物[N,N²-双(2-氧代-3-R1-5-R2-苯甲基)-N,N²-双(亚甲基-p-R3-C6H4)-乙二胺]Ti(OiPr)2 [R1 = t-Bu,R2 = Me,R3 = H (1b);R1 = R2 = t-Bu,R3 = H,(2b);R1 = R2 = Cl, R3 = H, (3b), R1 = t-Bu, R2 = Me, R3 = Cl (4b); R1 = R2 = t-Bu, R3 = Cl, (5b); R1 = R2 = R3 = Cl, (6b)] 已被设计为乙烯聚合的前催化剂。具体来说,当 1bâ6b 复合物与甲基铝氧烷(MAO)在 88 ± 0.5 psi 的乙烯条件下于 30 °C 处理 3 小时后,可生成具有宽分子量分布(PDI = 约 13.1â14.6)的高分子量聚乙烯聚合物(Mw = 约 7.2â8.3 à 105 g molâ1)。1bâ6b配合物是由[N2O2]H2配体1aâ6a与Ti(OiPr)4直接反应合成的,产率为69.86%。