| abstract |
"catalysts and polymerization and oligomerization processes". a polymerization catalyst is proposed comprising (1) a transition metal compound of formula a and optionally (2) an activating amount of a lewis acid activator, formula (a), where z is a five-membered heterocyclic group at least one carbon atom, at least one nitrogen atom and at least one other hetero atom selected from nitrogen, sulfur and oxygen and the remaining atoms in the ring being nitrogen or carbon; m is a group 3 to 11 metal in the periodic table or a lanthanide metal; and ^ 1 ^ and and ^ 2 ^ are divalent groups among (i) aliphatic hydrocarbon, (ii) alicyclic hydrocarbon, (iii) aromatic hydrocarbon, (iv) alkyl substituted aromatic hydrocarbon, (v) heterocyclic groups and (vi) hetero derivatives - replaced by groups (i) to (v); d ^ 1 ^ and d ^ 2 ^ are donor groups, x is an anionic group, l is a neutral donor group; n = m = zero or 1; y and z are zero or integers. catalysts are useful for the polymerization or oligopolymerization of 1-olefins. |