A transition metal complex having the following Formula (A): wherein the monovalent groups R.sup.1 and R.sup.2 are --R.sup.a, --OR.sup.b, --NR.sup.cR.sup.d, and --NHR.sup.e: the monovalent groups R.sup.a, R.sup.b, R.sup.c, R.sup.d and R.sup.e, and the divalent group R.sup.3 are (i) aliphatic hydrocarbon, (ii) alicyclic hydrocarbon, (iii) aromatic hydrocarbon, (iv) alkyl substituted aromatic hydrocarbon (v) heterocyclic groups and (vi) heterosubstituted derivatives of said groups (i) to (v); M is a Group (3) to (11) or lanthanide metal; E is phosphorus or arsenic; X is an anionic group, L is a neutral donor group; n is (1) or (2), y and z are independently zero or integers, such that the number of X and L groups satisfy the valency and oxidation state of the metal M. n is preferably (2) and the two resulting R.sup.1 groups are preferably linked. The complex can be used with optional activator to polymerise olefins ##STR00001##

 
Web www.patentalert.com

< Cold flow improvers for fuel oils of vegetable or animal origin

> Optical films incorporating cyclic olefin copolymers

~ 00426