Process for producing crystalline poly-.alpha.-olefins with a monocyclopentadienyl transition metal catalyst system

A process for producing crystalline poly-.alpha.-olefins comprising the steps of

• (i) contacting an .alpha.-olefin monomer at a temperature and pressure sufficient to polymerize such monomer with a catalyst system comprising;
• (A) an alumoxane, and
• (B) a group IV-B transition metal component of the formula ##STR12## wherein M is Zr, Hf or Ti in its highest formal oxidation state;
• R is a substituent group with "x" denoting the degree of substitution (x=0, 1, 2, 3 or 4) and each R is, independently, a radical selected from a group consisting of C.sub.1 -C.sub.20 hydrocarbyl radicals, substituted C.sub.1 -C.sub.20 hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical or any other radical containing a Lewis acidic or basic functionality, C.sub.1 -C.sub.20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the Group IV A of the Periodic Table of Elements, and halogen radicals, amido radicals, phosphido radicals, alkoxy radicals, alkylborido radicals or a radical containing Lewis acidic or basic functionality, or at least two adjacent R-groups are joined forming C.sub.4 -C.sub.20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand;
• (JR'.sub.z-2) is a heteroatom ligand in which J is an element with a coordination number of three from Group V A or an element with a coordination number of two from Group VI A of the Periodic Table of Elements, and each R' is, independently a radical selected from a group consisting of C.sub.1 -C.sub.20 hydrocarbyl radicals, substituted C.sub.1 -C.sub.20 hydrocarbyl radicals where one or more hydrogen atom is replaced by a halogen radical, an amido radical, a phosphido radical, and alkoxy radical or a radical containing a Lewis acidic or basic functionality, and "z" is the coordination number of the element J;
• each Q is, independently, any univalent anionic ligand or two Q's are a divalent anionic chelating ligand;
• T is a covalent bridging group containing a Group IV A or V A element;
• L is a neutral Lewis base where "w" denotes a number from 0 to 3;
• (ii) recovering a crystalline poly-.alpha.-olefin.