Synthesis and Characterization of Group 4 Fluorinated Bis(amidinates) and Their Reactivity in the Formation of Elastomeric Polypropylene

Bis(amidinate) titanium and zirconium bis(dimethylamido) complexes were prepared, and the dynamic behavior of the titanium complex containing perfluorinated amidinate ligand (11) was studied in detail. The variable-temperature NMR revealed the presence of two species in solution, in line with the different connection modes of the ligand to the metal center. The resulting complexes were tested as catalysts in the polymerization of propylene, and the resulting polymers were consistent with elastomeric high-molecular-weight atactic polypropylenes.