Coordination of Ln 3+ Ions to Perhydroxycucurbit[5]uril and the Formation of Supramolecular Self‐Assemblies in the Presence of [SiW 12 O 40 ] 4– Anions and Transition Metal Salts – Potential Application in the Isolation of Light Lanthanides

The coordination and supramolecular assemblies of lanthanide cations and perhydroxycucurbit[5]uril {(HO) 10 Q[5]} in the presence of [SiW 12 O 40 ] 4– anions and transition metal salts show significant differences as the lanthanide atomic number increases. The molecular capsule (HO) 10 Q[5] coordinates with the light lanthanide cations Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ , and Tb 3+ but does not coordinate with heavier Ln 3+ cations. However, (HO) 10 Q[5]/Na + ‐based molecular capsules form in the presence of the heavier lanthanide cations Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , and Lu 3+ under the same synthetic conditions. These differences could be key in establishing a strategy for the isolation of light lanthanides from their heavier counterparts.