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)(2)R-f8; b, (CH2)(3)R-f8; c, H (R-f8 = (CF2)(7)CF3)) 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.