We confirmed the stability of 3-LnLnʹ in solution by tracking formation of redistribution products by NMR (see ESI Table for details). Despite the short reaction times required, after isolation 3-YbEu and 3-DyYb were each stable in non-polar solvents for up to 24 h (with a final redistribution of only ca. 15% after several days). All spectra discussed herein were nevertheless recorded immediately after sample preparation. In the solid state, 3-LnLnʹ were stable for at least three months under inert atmosphere. However, rapid redistribution was observed in polar solvents, producing [Ln(Tp)2(hfac)] and other byproducts. Polar solvents were therefore not used in the spectroscopic analysis of 3-LnLnʹ.