Monocyclopentadienyl transition metal olefin polymerization catalysts

A catalyst system comprising:

• A) a Group IV B transition metal component of the formula:
• ##STR8## wherein M is Ti in its highest formal oxidation state:
• (C.sub.5 H.sub.5-y-x R.sub.x) is a cyclopentadienyl ring which is substituted with from zero to five substituent groups R, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent group 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 a 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 funtionality;
• or (C.sub.5 H.sub.5-y-x R.sub.x) is a cyclopentadienyl ring in which 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-1-y) 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, 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, an alkylborido radical, a phosido radical, an 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, provided that where Q is a hydrocarbyl such Q is different than the (C.sub.5 H.sub.5-y-x R.sub.x) or both Q together are an alkylidene, a cyclometallated hydrocarbyl or a divalent anionic chelating ligand;
• "y" is 0 or 1 when "w" is greater than 0;
• "y" is 1 when "w" is 0;
• when "y" is 1, 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;
• and
• (B) an alumoxane.