Unexpected Reactivity of Cp*Ga toward Fe−Cl Bonds: Synthesis and Structure of Cp*(Cp*Ga)2FeGaCl2·THF and of Cp*(CO)2FeGa(η2-Cp*)Cl

Abstract

The complex Cp*(Cp*Ga)2FeGaCl2·THF (1) was obtained in the reaction of FeCl2 with 3 equiv of η5-pentamethylcyclopentadienylgallium (Cp*Ga) in THF. For the formation of 1, the following unprecedented reaction sequence is proposed: (I) coordination of Cp*Ga to the iron center; (II) insertion of Cp*Ga into the Fe−Cl bond; (III) Cp*/Cl-[1,2]2-exchange; (IV) σ−π rearrangement of the Cp* ligand. A comparable insertion step could be observed in the reaction of Cp*Ga with Cp*(CO)2FeCl where the compound Cp*(CO)2FeGa(η2-Cp*)Cl (2) was formed. 1 and 2 are characterized by NMR, IR, and X-ray crystallographic data and by elemental analysis.