title: Chromium complexes supported by phenanthrene-imine derivative ligands: synthesis, characterization and catalysis on isoprene cis-1,4 polymerization.
abstract: Reactions of CrCl(2)(THF)(2) with N-aryl-9,10-iminophenanthraquinone in CH(2)Cl(2) give the monoimine chromium complexes (Ar)IPQCrCl(2)(THF)(2) (1, Ar = 2,6-Me(2)C(6)H(3); 2, Ar = 2,6-Et(2)C(6)H(3); 3, Ar = 2,6-(i)Pr(2)C(6)H(3)). Molecular structures of 1 and 3 were revealed to be monomeric with the chromium atoms in distorted octahedral geometries. Similar reactions of CrCl(2)(THF)(2) with N,N-bis(arylimino)phenanthrene ligands afford the diimine complexes (Ar1,Ar2)BIPCrCl(μ-Cl)(3)Cr(THF)(Ar1,Ar2)BIP (4, Ar(1) = Ar(2) = 2,6-Me(2)C(6)H(3); 5, Ar(1) = Ar(2) = 2,6-Et(2)C(6)H(3); 6, Ar(1) = Ar(2) = 2,6-(i)Pr(2)C(6)H(3); 7, Ar(1) = 2,6-Me(2)C(6)H(3), Ar(2) = 2,6-(i)Pr(2)C(6)H(3)). The X-ray diffraction analysis shows that 4, 5, and 7 are chlorine-bridged dimers with each chromium atom in a distorted octahedral geometry. Upon activation with MAO, all these complexes exhibit good catalytic activities for isoprene polymerization affording polyisoprene with predominantly a cis-1,4 unit.
authors.affiliation: State Key Laboratory for Supramolecular Structure and Materials, Jilin University, Changchun, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.forename: Xuyang
authors.initials: X
authors.lastname: Luo
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Long
authors.initials: L
authors.lastname: Huang
authors.forename: Si-meng
authors.initials: SM
authors.lastname: Gao
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liu
authors.forename: Qiaolin
authors.initials: Q
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Mu