Catalyst system based on monoazadiene metal complexes

A catalyst system of:

• a) A monoazadiene metal complex of the formula ##STR11## wherein M is a metal from Group IIIb, IVb, Vb, VIb or the lanthanides or actinides of the periodic table,
• A signifies an optionally monobridged or polybridged anionic ligand,
• R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 are the same or different and stand for hydrogen, a cyano group, halogen, a C.sub.1 to C.sub.20 alkyl group, a C.sub.1 to C.sub.10 fluoroalkyl group, a C.sub.6 to C.sub.10 fluoroaryl group, a C.sub.1 to C.sub.10 alkoxy group, a C.sub.6 to C.sub.20 aryl group, a C.sub.6 to C.sub.10 aryloxy group, a C.sub.2 to C.sub.10 alkenyl group, a C.sub.7 to C.sub.40 arylalkyl group, a C.sub.7 to C.sub.40 alkylaryl group, a C.sub.8 to C.sub.40 arylalkenyl group, a C.sub.2 to C.sub.10 alkynyl group, a silyl group optionally substituted by C.sub.1 -C.sub.10 hydrocarbon radicals
• or
• R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 form, together with the atoms linking them in each case, one or more aliphatic or aromatic ring systems, which may contain one or more heteroatoms of O, N or S and have 5 to 10 carbon atoms,
• L signifies a neutral ligand,
• n is a number from 0 to 10,
• m is 0, 1, 2, 3 or 4 and
• k is 1, 2, or 3 and the sum of m+k is 1 to 5, as a function of the oxidation number of M
• and
• b) a co-catalyst suitable for activating the metal complex a),
• wherein the molar ratio of component a) to component b) is in the range of 1:0.1 to 1:10,000.