Cubane Clusters Containing Lanthanide Ions: (py)8Yb4Se4(SePh)4 and (py)10Yb6S6(SPh)6

Chalcogenolates of the smaller lanthanides (Ln) react with elemental chalcogen to give the first examples of cubane clusters containing Ln ions. Both (py)8Yb4Se4(SePh)4 and (py)10Yb6S6(SPh)6 were isolated; the Se compound exhibits the familiar M4E4 structural motif, while the S compound is best described as a double cube. Both structures reveal unusual trends in Yb−chalcogenido bond lengths.