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

The complex Cp*(Cp*Ga)(2)FeGaCl2. THF (1) was obtained in the reaction of FeCl2 with 3 equiv of eta(5)-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) sigma-pi rear-rangement of the Cp* ligand. A comparable insertion step could be observed in the reaction of Cp*Ga with Cp*(CO)(2)FeCl where the compound Cp*(CO)(2)FeGa(eta(2)-Cp*)-Cl (2) was formed. 1 and 2 are characterized by NMR, IR, and X-ray crystallographic data and by elemental analysis.