2,6-Diiminopyridine Iron(II) Dialkyl Complexes. Interaction with Aluminum Alkyls and Ethylene Polymerization Catalysis

Bis(pyridine)iron dialkyl complexes FeR<sub>2</sub>Py<sub>2</sub> (R = CH<sub>2</sub>Ph, CH<sub>2</sub>CMe<sub>2</sub>Ph, and CH<sub>2</sub>SiMe<sub>3</sub>) react with 2,6-diiminopyridine ligands, affording the corresponding organoiron complexes. The complex Fe(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub>(C<sub>5</sub>H<sub>3</sub>N-2,6-(C(N-mesityl)Me)<sub>2</sub>, <b>4a</b>, becomes an active ethylene polymerization catalyst upon treatment with Al or Zn alkyls. A catalytically active 1:1 Fe/Al adduct has been detected in solution by <sup>1</sup>H and UV−vis spectroscopies.