A New Vanadium (III) Complex of 2,6-Bis(3,5-diphenylpyrazol-1-ylmethyl)pyridine as a Catalyst for Ethylene Polymerization
作者:Hanna Abbo、Salam Titinchi
DOI:10.3390/molecules18044728
日期:——
The tridentate ligand 2,6-bis(3,5-diphenylpyrazol-1-ylmethyl)pyridine, abbreviated as 2,6-[(3,5-ph2pz-CH2)2-py], a new pyridine-pyrazole derivative, was prepared from 2,6-bis(bromomethyl)pyridine and 3,5-diphenylpyrazole. The ligand was characterized by means of elemental analyses, ATR-IR, 1H- and 13C-NMR spectroscopy and single crystal X-ray crystallography. Using this ligand, a new mononuclear vanadium (III) complex, 2,6-[(3,5-ph2pz)CH2]2py}VCl3 was prepared and characterized by elemental analysis, ATR-IR and HR-MS. The complex was investigated as a catalyst for ethylene polymerization and compared with 2,6-[(3,5-Me2pz)CH2]2py}VCl3 to explore the effect of the substituent on the pyrazolyl rings on ethylene polymerization. High catalytic activity was observed at ambient temperature. After treatment with AlEtCl2, these complexes showed high activity for ethylene polymerization converting ethylene to highly linear polyethylene and affording high molecular weight polymers (up to 1.0 × 106 g/mol) with unimodal molecular weight distributions.
三齿配体2,6-双(3,5-二苯基吡唑-1-基甲基)吡啶,简称2,6-[(3,5-ph2pz-CH2)2-py],是一种新的吡啶-吡唑衍生物,由2,6-双(溴甲基)吡啶和3,5-二苯基吡唑制备而成。该配体通过元素分析、ATR-IR、1H和13C NMR光谱以及单晶X射线晶体学进行了表征。利用这种配体,合成了一种新的单核钒(III)配合物2,6-[(3,5-ph2pz)CH2]2py}VCl3,并通过元素分析、ATR-IR和HR-MS进行了表征。该配合物被研究为乙烯聚合的催化剂,并与2,6-[(3,5-Me2pz)CH2]2py}VCl3进行了比较,以探究吡唑环上的取代基对乙烯聚合的影响。在室温下观察到了高的催化活性。经过AlEtCl2处理后,这些配合物显示出高的乙烯聚合活性,将乙烯转化为高度线性的聚乙烯,并得到单峰分子量分布的高分子量聚合物(高达1.0×10^6 g/mol)。