一类新型硅烷基Schiff碱亚胺络合过渡金属催化剂的合成及催化乙烯性能研究  

Synthesis and ethylene oligomerization behavior of transition metal catalysts based on silylated-Schiff base ligand

作　　者：张宇[1] 郭丽君 李锋[1] 黄金[1,2] 张鹭 张东芳 李翠勤 ZHANG Yu;GUO Li-jun;LI Feng;HUANG Jin;ZHANG Lu;ZHANG Dong-fang;LI Cui-qin(Key Laboratory of Oil Gas&Chemical Technology,College of Chemistry&Chemical Engineering,Northeast Petroleum University,Daqing 163318,China;Heilongjiang Provincial Key Laboratory of Oilfield Applied Chemistry and Technology,Daqing Normal University,Daqing 163712,China)

机构地区：[1]东北石油大学化学化工学院石油与天然气化工省重点实验室,黑龙江大庆163318 [2]大庆师范学院黑龙江省油田应用化学与技术重点实验室,黑龙江大庆163712

出　　处：《分子科学学报》2021年第4期360-367,共8页Journal of Molecular Science

基　　金：黑龙江省自然科学基金资助项目(E2018012)。

摘　　要：以γ-氨丙基三乙氧基硅烷和水杨醛为原料,通过席夫碱反应合成一类硅烷基Schiff碱亚胺配体;分别以六水氯化镍和六水氯化钴为络合试剂,通过络合反应合成两类硅烷基Schiff碱亚胺络合过渡金属催化剂.元素分析、FT-IR、1H NMR和ICP证实合成的硅烷基Schiff碱亚胺配体及其相应的过渡金属催化剂的结构与其理论结构相符.两类硅烷基Schiff碱亚胺络合过渡金属催化剂具有良好的催化乙烯齐聚活性,且其催化性能不仅受助催化剂结构和主催化剂活性中心种类的影响,而且还受聚合反应参数的影响.甲基铝氧烷(MAO)为助催化剂,环己烷为溶剂时,聚合活性和齐聚产物中C8以上烯烃的含量较高;当Al/Co物质的量比为500、反应温度为25℃、反应压力为0.5 MPa和反应时间为30 min时,硅烷基Schiff碱亚胺络合钴催化剂催化乙烯齐聚的活性为1.13 g·μmol^(-1)·h^(-1),齐聚产物中C8以上烯烃含量为52.70%.受电子云密度的影响,硅烷基Schiff碱亚胺络合镍催化剂的催化活性高于相应的钴催化剂.A novel silylated-Schiff base ligand was synthesized by the Schiff base reaction with 3-aminopropyl-trimethoxysilane and salicylaldimine as materials, and two transition metal catalysts based on silylated-Schiff base ligand were synthesized with NiCl2·6 H2O and CoCl2·6 H2O, respectively. The structures of the ligand and the catalysts were verified by elemental analysis, FT-IR, 1H NMR and ICP. The catalytic properties of two transition metal catalysts based on silylated-Schiff base ligand were evaluated for the oligomerization of ethylene in combination with various cocatalysts and two catalysts exhibited the good catalytic properties on the oligomerization of ethylene. The catalytic behavior was affected not only by the Lewis acidity of the cocatalyst but also by the solubilty of the cocatalyst in the reaction. Upon activated by the cocatalysts with the high Lewis acidity and the high solubility, the precatalysts had the high catalytic activity. Compared to the other three cocatalysts, the catalytic activity and the selectivity of C8+ olefin for the cobalt(Ⅱ) catalyst based on silylated-Schiff base ligand were higher using MAO as co-catalyst in cyclohexane and were 0.57 g·μmol^(-1)·h^(-1) and 61.47%, respectively. The oligomerization parameters had great influence on the catalytic activity and the product distribution for cobalt(Ⅱ) catalyst based on silylated-Schiff base ligand. In this manuscript, the influences of Al/Co ratio, reaction temperature and ethylene pressure on ethylene oligomerization were also investigated using the cobalt(Ⅱ) catalyst based on silylated-Schiff base ligand as precatalyst, MAO as cocatalyst and cyclohexane as solvent. The precatalyst needed a certain amount of cocatalyst to activate and formed the Co species to catalyze the ethylene oligomerization. The catalytic activity and the selectivity of C8 olefin increased firstly and then decreased with increasing of the catalyst dosage and the cocatalyst dosage, and the high reaction pressure caused to the high catalytic activity

关 键 词：硅烷基希夫碱配体 乙烯齐聚 后过渡金属催化剂 高碳烯烃 

分 类 号：O643[理学—物理化学]