Self-Assembly of Pseudorotaxane Structures from a Dicopper(II) Molecular Cage and Dicarboxylate Axles

Novel pseudorotaxane structures have been obtained by using a bis[tris(2-aminoethyl)amine (tren)] azacryptand, copper(II) ions, and a dianionic molecular axle as the building blocks. The threading, occurring at pH 7 in a methanol/water mixture, is promoted by the strong binding of the axle’s dicarboxylate unit to the copper(II) centers within the azacryptate’s cavity. This work shows that bis(tren) cages can be successfully applied as building blocks in the assembly of supramolecular architectures in an aqueous solution.