| abstract |
Catalyst composition comprising: (a) a binuclear chromium (II) complex; (b) a ligand of the general structure (A) R1R2P-N (R3) -P (R4) -N (R5) -H or (B) R1R2P-N (R3) -P (R4) -N (R5) -PR6R7, in which R1, R2, R3, R4, R5, R6 and R7 are independently selected from amino, C1-C10 alkyl, aryl and substituted aryl, in which the PNPN or PNPNP unit is optionally part of a system of ring, in which at least one of the atoms of P or N of the structure (A) or of the structure (B) is a ring member, the ring being formed by one or several constituent compounds of the structures (A ) or (B) by substitution by formally eliminating two whole groups R1-R7 or H, one atom of each of two groups R1-R7, or one whole group R1-R7 or H and one atom of another group R1- R7, and joining the sites of unsaturated valence formally created by a covalent bond by constitutive compound to provide the same valence as initially present at a given site; and (c) an activator or cocatalyst |