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Synthesis of novel zirconium complexes bearing mono‐Cp and tridentate Schiff base [ONO] ligands and their catalytic activities for olefin polymerization
Author(s) -
Chen Qihui,
Huang Jiling
Publication year - 2006
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1124
Subject(s) - methylaluminoxane , chemistry , schiff base , dilithium , polymerization , ligand (biochemistry) , ethylene , polymer chemistry , medicinal chemistry , catalysis , 1 hexene , zirconium , stereochemistry , metallocene , inorganic chemistry , organic chemistry , ion , biochemistry , deprotonation , receptor , polymer
A series of novel zirconium complexes {R 2 Cp[2‐R 1 ‐6‐(2‐CH 3 OC 6 H 4 NCH)C 6 H 3 O]ZrCl 2 ( 1 , R 1 = H, R 2 = H, 2 : R 1 = CH 3 , R 2 = H; 3 , R 1 = t Bu, R 2 = H; 4 , R 1 = H, R 2 = CH 3 ; 5 , R 1 = H, R 2 = n ‐Bu)} bearing mono‐Cp and tridentate Schiff base [ONO] ligands are prepared by the reaction of corresponding lithium salt of Schiff base ligands with R 2 CpZrCl 3 ·DME. All complexes were well characterized by 1 H NMR, MS, IR and elemental analysis. The molecular structure of complex 1 was further confirmed by X‐ray diffraction study, where the bond angle of ClZrCl is extremely wide [151.71(3)°]. A nine‐membered zirconoxacycle complex Cp(O2C 6 H 4 NCHC 6 H 4 ‐2O)ZrCl 2 ( 6 ) can be obtained by an intramolecular elimination of CH 3 Cl from complex 1 or by the reaction of CpZrCl 3 ·DME with dilithium salt of ligand. When activated by excess methylaluminoxane (MAO), complexes 1–6 exhibit high catalytic activities for ethylene polymerization. The influence of polymerization temperature on the activities of ethylene polymerization is investigated, and these complexes show high thermal stability. Complex 6 is also active for the copolymerization of ethylene and 1‐hexene with low 1‐hexene incorporation ability (1.10%). Copyright © 2006 John Wiley & Sons, Ltd.