Abstract: This description addresses ionic compositions of matter comprising positively charged cations [Ct]+ and negatively charged anions [A]−, said anion comprising a central core Group 13 element to which are bound fluoroaryl ligands, at least one of said fluoroaryl ligands being substituted with a siloxy group represented by the symbols—SiOR3, wherein R is a C1-C30 hydrocarbyl or hydrocarbylsilyl substituent. [Ct]+ may be selected from any capable of use with olefin polymerization catalysts and typically will be from the group consisting of anilinium and ammonium cations, trityl carbenium cations, Group 11 metal cations, silylium cations, the cations of the hydrated salts of Group 1 or 2 metals, and derivatives of the foregoing anilinium, ammonium, trityl carbenium, and silylium cations containing C1-C20 hydrocarbyl, hydrocarbylsilyl, or hydrocarbylamine substituents for one or more hydrogen atoms of said cations.

Abstract: The invention is directed to olefin polymerization processes using bridged hafnocene catalyst complexes that are surprisingly stable under high temperature olefin polymerization processes such that olefin copolymers can be prepared with high molecular weights and catalyst activities. More specifically, the invention is a polymerization process for ethylene copolymers having a melt index of about 0.850 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 60° C. to 250° C.