Bulky Bis(alkylamidinate) Complexes of Group 4. Syntheses and Characterization of M(CyNC(R‘)NCy)2Cl2 and Zr(CyNC(Me)NCy)2Me2 (R‘= Me, M = Ti, Zr, Hf; R‘ = tBu, M = Zr)

Synthesis of a series of bis(alkylamidinate) group 4 compounds of the general formula M(CyNC(CH3)NCy)2Cl2 (M = Ti (1), Zr (2), Hf (3); Cy = cyclohexyl), Zr(CyNC(CMe3)NCy)2Cl2 (4), and Zr(CyNC(CH3)NCy)2(CH3)2 (5) are reported. In the presence of methylaluminoxane (MAO) as a cocatalyst, compounds 1−5 are active ethylene polymerization catalysts.