新型树枝状PNP铬催化剂的合成及催化性能

发布时间：2018-04-26 14:42

  本文选题：.代聚酰胺-胺 + 树枝状PNP配体　； 参考：《高等学校化学学报》2017年07期

【摘要】：以1.0代聚酰胺-胺(PAMAM)为配体骨架,氯代二苯基膦为原料,通过取代反应合成了1种含有较大空间位阻的新型树枝状PNP配体,再以Cr Cl3(THF)3为络合试剂,通过络合反应合成树枝状PNP铬催化剂.采用傅里叶变换红外光谱(FTIR)、紫外-可见分光光度计(UV-Vis)、核磁共振波谱(NMR)、电喷雾电离质谱(ESI-MS)和元素分析等手段证实合成的新型树枝状PNP配体及其铬催化剂的结构与理论设计的结构一致.以甲基铝氧烷(MAO)为助催化剂,对乙烯齐聚反应进行了研究,考察了溶剂种类、反应温度、反应压力及Al/Cr摩尔比对该催化剂活性和选择性的影响.结果表明,以甲苯为溶剂,MAO为助催化剂,当反应温度为25℃,反应压力为0.9 MPa,Al/Cr摩尔比为500时,该催化剂的活性高达2.15×105g/(mol Cr·h),催化剂对乙烯三聚、四聚反应的选择性共达到36.76%.
[Abstract]:A new dendritic PNP ligand containing large steric resistance was synthesized by substitution reaction using 1.0 generation polyamide-amine (PAMAM) as ligand skeleton and chlorodiphenylphosphine as raw material. Cr Cl3(THF)3 was then used as complexing reagent. Dendritic PNP chromium catalyst was synthesized by complexation reaction. The structure and mechanism of the new dendritic PNP ligands and their chromium catalysts were confirmed by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectrophotometer (UV-Visn), nuclear magnetic resonance spectroscopy (NMR), electrospray ionization mass spectrometry (ESI-MS) and elemental analysis. The structure of the design is consistent. The oligomerization of ethylene was studied with methyl aluminoalkane Mao as the co-catalyst. The effects of solvent type, reaction temperature, reaction pressure and molar ratio of Al/Cr on the activity and selectivity of the catalyst were investigated. The results show that when the reaction temperature is 25 鈩，

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