Synthesis and characterization of scandium complexes with reduced ligands: Crystal structures of Cp∗ScI2, [Cp∗ScI(bpy)]2, and [Cp∗ScCl(bpy)]2

The reaction of Cp∗ScI2(bpy) (3) with alkali metal-based reductants produced [Cp∗ScI(bpy)]2 (5), a compound which features a strong π-stacking interaction between the bipyridine ligands. The chloride analog, [Cp∗ScCl(bpy)]2 (7), was prepared from the reaction between Li2(dme)2bpy (6) and Cp∗ScCl2. Spectroscopic and crystallographic data indicate that the bipyridine ligands in 5 and 7 are reduced to their radical anion form.