Fig. 1: Supramolecular formation of [Ln2L13], [Ln4L16]. [Tb2L23], and [Ln2L33].

The length of the spacer will greatly affect the supramolecular formation. With the use of a shorter ligand L1, helicate-to-tetrahedron transformation was observed. For longer L2 and L3, only stable helicates were formed and no helicate-to-tetrahedron transformation was observed.