摘要
Mononaclear carbon bridged cyclopentadienyl chromium complexes of the type [ （ C5H4 ） C （ C5 H10 ） CH2 （ C5 H4 N） ] CrCl2 （1） , [ （ C5 H4 ） C（ CH3 ）2 CH2 （ C5 H4 N） ] CrCl2 （ 2 ） and homodinuclear chromium complex of the type （ CH3 ）2 C｜ [ （ C5 H3 ） C（ CH3 ）2 CH2 （ C5 H4 N） ] CrCl2｜2 （ 3 ） were prepared by treutment of the lithium salts of eyclopentadiene ligands with pyridyl group with CrCl3 （ THF）3 in THF solution. All complexes were structurally charncterized by mass spectra and elemental analysis. The structure of complex 1 was determined by X-ray diffraction analysis. Activated by MAO , complexes 1 and 2 are efficient catalysts in the polywerization of ethylene yielding polyethylene （ PE ） with a high molecular weight （ My ranging from 225800 to 637800 g·mol^-1 , 30≤ Tp≤70℃ under 0.9 MPa monomer pressure ）. High activities of polymerization are related to the unique electronic and sterie structure of complexes 1 and 2 . The melting points of the polymers determined by OSC and charueterization data of ^13 C NMR all show the synthesis of linear polyethylene （LPE） with a low branching extent.
Mononaclear carbon bridged cyclopentadienyl chromium complexes of the type [ （ C5H4 ） C （ C5 H10 ） CH2 （ C5 H4 N） ] CrCl2 （1） , [ （ C5 H4 ） C（ CH3 ）2 CH2 （ C5 H4 N） ] CrCl2 （ 2 ） and homodinuclear chromium complex of the type （ CH3 ）2 C｜ [ （ C5 H3 ） C（ CH3 ）2 CH2 （ C5 H4 N） ] CrCl2｜2 （ 3 ） were prepared by treutment of the lithium salts of eyclopentadiene ligands with pyridyl group with CrCl3 （ THF）3 in THF solution. All complexes were structurally charncterized by mass spectra and elemental analysis. The structure of complex 1 was determined by X-ray diffraction analysis. Activated by MAO , complexes 1 and 2 are efficient catalysts in the polywerization of ethylene yielding polyethylene （ PE ） with a high molecular weight （ My ranging from 225800 to 637800 g·mol^-1 , 30≤ Tp≤70℃ under 0.9 MPa monomer pressure ）. High activities of polymerization are related to the unique electronic and sterie structure of complexes 1 and 2 . The melting points of the polymers determined by OSC and charueterization data of ^13 C NMR all show the synthesis of linear polyethylene （LPE） with a low branching extent.
基金
FundedbytheNationalNaturalScienceFoundationofChina(20074028,20374043),SinopecItem(X503027)andTechnologyInnovationItemofHubeiProvincialEducationDepartment(J200511001)
