Synthesis, solid state and DFT structure and olefin polymerization capability of a unique base-free dimeric methyl titanium dication

Reaction of Cp*Ti{NC(Ar(F(2)))N(i)Pr(2)}Me(2) (1, Ar(F(2)) = 2,6-C(6)H(3)F(2)) with [Ph(3)C][B(C(6)F(5))(4)] gave the base-free structurally authenticated dication [Cp*(2)Ti(2){NC(Ar(F(2)))N(i)Pr(2)}(2)(mu-Me)(2)][B(C(6)F(5))(4)](2) (3-[BF(20)](2)) containing two doubly alpha-agostic bridging methyl groups. 3-[BF(20)](2) is a highly effective ethylene-propylene polymerization catalyst at 90 degrees C, and its performance is identical to the catalyst generated in situ from 1 and [Ph(3)C][B(C(6)F(5))(4)].