摘要 |
<p>Novel catalyst compositions comprising a cationic transition metal complex of the formula (Pd(II)S4-xLx)+2(A)-ny, wherein: Pd(II) is palladium having a valence of +2; S is a synthesis solvent; L is a monodendate, bidendate or tridendate ligand or ligands having one or more bonding sites; x is an integer from 1 to 3 and is equal to the total number of ligand bonding sites; A is a weakly or non-coordinating anion capable of stabilizing the complex in its cationic form; and n is 1 or 2 and y is 2 or 1; provided that (i) when n is 1, y is 2 and when n is 2, y is 1; and (ii) when the anion A is tetrafluoroborate, the organometallic complex is not (tris(acetonitrile)palladium(II)triphenylphosphine), (bis(acetonitrile)palladium(II)bis(triphenylphosphine)), ((acetonitrile)palladium(II)tris(triphenylphosphine)) or (bis(acetonitrile)palladium(II) 1,3-bis(diphenylphosphino)propane). The new catalyst compositions are useful for the copolymerization of carbon monoxide and at least one ethylenically unsaturated hydrocarbon to produce linear alternating polymers. The rate of polymerization is enhanced by including an alcohol, such as methanol, in the polymerization mixture.</p> |