A New Vanadium (III) Complex of 2,6-Bis(3,5-diphenylpyrazol-1-ylmethyl)pyridine as a Catalyst for Ethylene Polymerization

Molecules

Hanna S. Abbo¹ 

关键词: pyrazole;    2;    6-bis(pyrazol-1-ylmethyl)pyridine;    vanadium complex;    ethylene polymerization;    high density polyethylene;   

DOI  :  10.3390/molecules18044728

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.