Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
68785 | Journal of Molecular Catalysis A: Chemical | 2007 | 6 Pages |
Some new chromium(II) complexes were synthesized by reacting CrCl2(thf) with various bidentate phosphines [bis(diphenylphosphino)methane (dppm); 1,2-bis(diphenylphosphino)ethane (dppe); 1,3-bis(diphenylphosphino)propane (dppp); bis(diphenylphosphino)amine (dppa)] and a new family of catalysts for the polymerization of butadiene was prepared by reacting the above chromium complexes with methylaluminoxane (MAO). These systems were found to be in some cases extremely active and they gave predominantly 1,2-polybutadienes (1,2 content >85%) having different tacticity (syndiotactic or predominantly isotactic) depending on the phosphine ligand bonded to the chromium atom. The influence of the type of ligand on catalyst activity and selectivity is discussed.
Graphical abstractSome new chromium(II) complexes obtained by reacting CrCl2(thf) with various bidentate phosphines [bis(diphenylphosphino)methane (dppm); 1,2-bis(diphenylphosphino)ethane (dppe); 1,3-bis(diphenylphosphino)propane (dppp); bis(diphenylphosphino)amine (dppa)] were used, in combination with MAO, for polymerizing butadiene. They were found to be in some cases extremely active and they gave predominantly 1,2-polybutadienes (1,2 content >85%) having different tacticity (syndiotactic or predominantly isotactic) depending on the phosphine ligand bonded to the chromium atom. Figure optionsDownload full-size imageDownload as PowerPoint slide