CATIONIC D(0)/F(0) METALLOCENE CATALYSTS - PROPERTIES OF BINUCLEAR ORGANOBORANE LEWIS-ACID COCATALYSTS AND WEAKLY COORDINATING COUNTERANIONS DERIVED THEREFROM

Reaction of (t)BuCH2CH(BCl2)2 with LiC6F5 yields the binuclear organo-Lewis acid (t)BuCH2CH-[B(C6F5)2]2, which can be converted with KEt3BH, followed by metathesis, into the salt [HN(n)Bu3]+{(t)BuCH2-CH[B(C6F5)2]2H}-. Reaction of this salt with Cp'2Th-(CH3)2 (Cp' = eta5-Me5C5) yields the cationic metallocene complex Cp'2ThCH3+{(t)BuCH2CH[B(C6F5)2]2H}- (5), which is a highly active catalyst for ethylene polymerization and 1-hexene hydrogenation. The THF adduct, Cp'2Th-(CH3)THF+{(t)BuCH2CH[B(C6F5)2]2H}-, has been characterized by X-ray diffraction.