title: Activation of Single-Component Nickel(II) Polyethylene Catalysts via Phase Transfer of Fluorous Phosphine Ligands.
abstract: The nickel salicylaldiminato phosphine complexes [1,2,3-C6H3(9-anthracenyl)O(CH═N(2,6-C6H3(iPr)2)]Ni(Me)[P(4-C6H4R)3] (4; R = a, (CH2)2Rf8; b, (CH2)3Rf8; c, H (Rf8 = (CF2)7CF3)) are prepared from the corresponding phosphines 3a-c and nickel NCMe adduct (46-68%). These are applied as catalysts for ethylene polymerization in toluene and fluorous/toluene liquid/liquid biphasic mixtures. Under the latter conditions, the fluorous phosphines 3a,b that must dissociate to generate the active catalyst migrate to the fluorous phase (partition coefficients 97.5:2.5 and 66.6:33.4 vs <0.5:>99.5 for 4a,b). Catalysts 4a,b show marked accelerations under biphasic conditions, but 4c (which has a lipophilic phosphine ligand) does not. Under all conditions, 4a,b are faster catalysts than the Ni(Ph)(PPh3) analogue, a previously reported benchmark.
authors: Department of Chemistry, Texas A&M University , P.O. Box 30012, College Station, Texas 77842-3012, United States.
authors: Zhenxing
authors: Z
authors: Xi
authors: Department of Chemistry, Texas A&M University at Qatar , P.O. Box 23874, Doha, Qatar.
authors: Hassan S
authors: HS
authors: Bazzi
authors: Department of Chemistry, Texas A&M University , P.O. Box 30012, College Station, Texas 77842-3012, United States.
authors: John A
authors: JA
authors: Gladysz