Synthesis, Structural Characterization, Catalytic Properties, and Theoretical Study of Compounds Containing an Al−O−M (M = Ti, Hf) Core

Two single oxygen-bridged heterobimetallic oxides of Al(III) with group 4 metals (Ti, Hf) have been prepared. The
reaction of LAlMeOH (1) [L = CH(N(Ar)(CMe))2, Ar = 2,6-iPr2C6H3] with dimethylmetallocenes of Ti and Hf in
toluene (80 °C) and ether (room temperature), respectively, resulted in the formation of LAl(Me)(μ-O)M(Me)Cp2 [M
= Ti (2), Hf (3)] in moderate to good yield. Compounds 2 and 3 were characterized by elemental analysis, IR,
NMR (1H and 13C), EI-MS, and single-crystal X-ray structural analysis. Furthermore, compound 2 showed good
catalytic activity in ethylene and styrene homopolymerization, while compound 3 is less active in ethylene
polymerization. The styrene polymerization yields atactic polystyrene.