Highly soluble olefin polymerization catalyst activator

A catalyst activator comprising a cation which is a Bronsted acid capable of donating a proton, and an inert, compatible, noncoordinating, anion, characterized by a solubility at 25.degree. C. in hexane, cyclohexane or methylcyclohexane of at least 5 weight percent said activator having the formula:

• ›L*-H!.sub.d.sup.+ A.sup.d-, wherein:
• L* is a nitrogen, sulfur or phosphorus containing Lewis base comprising from 1 to 3 C.sub.10-40 alkyl groups with a total of from 12 to 100 carbons;
• (L*-H).sup.+ is a Bronsted acid;
• A.sup.d- is selected from the group consisting of:
• A) sterically shielded diboron anions corresponding to the formula:
• ##STR6## wherein:
• S is alkyl, fluoroalkyl, aryl, or fluoroaryl (and where two S groups are present additionally hydrogen),
• Ar.sup.F is fluoroaryl, and
• X.sup.1 is either hydrogen or halide and
• B) anions corresponding to the formula:
• ›M'.sup.k+ Q.sub.n' !.sup.d-, wherein:
• k is an integer from 1 to 3;
• n' is an integer from 2 to 6;
• n'-k=d;
• M' is an element selected from Group 13 of the Periodic Table of the Elements;
• and
• Q independently each occurrence is selected from hydride, dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, and halosubstituted-hydrocarbyl radicals, said Q having up to 20 carbons with the proviso that in not more than one occurrence is Q halide;
• and
• d is an integer from 1 to 3.

A catalyst activator having the formula:

• (L*-H).sup.+ (BQ'.sub.4).sup.- ;
• wherein,
• L* is a nitrogen, sulfur or phosphorus containing Lewis base comprising 2 C.sub.10-40 alkyl groups with a total of from 21 to 90 carbons;
• B is boron in an oxidation state of 3;
• and
• Q' is a fluorinated C.sub.1-20 hydrocarbyl group.