Patent ID: 6894132

Claim:
A process for polymerizing an olefin monomer to form a syndiotactic/atactic block polyolefin comprising: a) providing a catalyst of the general formula: R″(C 4 R′ m C 5 C 4 R′ n )XMeQ wherein X is an hetero-atom ligand with one or two lone pair electrons selected from the elements of Group VA or VIA which can be substituted or non-substituted; (C 4 R m ′C 5 C 4 R n ′) is a symmetrically substituted, 3,6-substituted fluorenyl; R′ is hydrogen or hydrocarbyl radical having from 1-20 carbon atoms, a halogen, an alkoxy, an alkoxy alkyl or an alkylamino or alkylsilyl radical, each R′ may be the same or different and m and n independently are 1, 2, 3 or 4, with the proviso that the bilateral symmetry is maintained; R″ is a structural bridge between X and the (C 4 R′ m C 5 C 4 R′ n ) ring to impart stereorigidity; Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; Me is a Group IIIB, IVB, VB, or VIB metal as positioned in the Periodic Table of Elements; and Me can be in any of its theoretically possible oxidation states; b) introducing the catalyst into a polymerization reaction zone containing an olefin monomer and maintaining the reaction zone under polymerization reaction conditions to produce a syndiotactic atactic block polymer; and c) recovering said syndiotactic/atactic block polymer from said polymerization reaction zone.