Synthesis and catalytic activity of allyl, methallyl and methyl complexes of nickel(II) and palladium(II) with biphosphine monoxide ligands: oligomerization of ethylene and copolymerization of ethylene and carbon monoxide

The syntheses of new cationic nickel complexes {[eta(3)-methallyl]Ni[ kappa (2) P,O-Ph-2 P(X)P(O)Ph-2]}SbF6, (1)-(2) [X = (o-C6H4) (1), (NH), (2)1 hav e been accomplished. The complexes oligomerize ethylene to linear cl-olefin s with selectivities as high as 89%. A dependence of oligomerization grade and activity on backbone geometry was shown. New cationic allyl and methyl complexes of palladium(II) [(CH3CN)(Me)Pd(kappa(2)P,O-Ar2P(CH2)(n)P(O)Ar-2) ]X [n = 1-3, X = BF4, Ar = C6H5 (18-20)] [n = 1, X = SbF6, Ar =p-tolyl (23) ; n = 1 or 2, X = SbF6, Ar = C6H5 (21) or (22)]; [( eta(3)-C3H5Pd(kappa(2)P ,O- Ph2P(CH2)(n)P(O)Ph-2)]X, [n = 2, X=triflate (10), tosylate (13); n=3, X =triflate (11), tosylate (14)], ([ eta(3)- C3H5)]Pd(kappa(2)P,O-Ar2P(CH2)(n )P(O)Ar-2)]X, [n = 1, X = SbF6, Ar =p-tolyl (17); n = 2, X = SbF6 Ar = C6H5 (16)] have been synthesized in good yields. These complexes have been used in the catalytic oligomerization of ethylene, and in the catalytic alternat ing copolymerization of ethylene and carbon monoxide, to yield polyketones. (C) 2000 Elsevier Science B.V. All rights reserved.