Palladium(II)-directed self-assembly of dynamic donor-acceptor [2]catenanes

Highly efficient syntheses of donor-acceptor 2]catenanes were developed using a combination of templation and reversible metal-ligand coordination. The desired 2]catenanes were obtained within minutes through a five-component assembly, involving a donor-containing crown ether, an acceptor-containing ligand, two Pd(II) metal centers, and a dipyridyl ligand. The 2]catenane formation was characterized by 1H NMR and UV-vis spectroscopies and cold-spray ionization mass spectrometry. In particular, great translational selectivity was observed when a crown ether with two different donor units was employed.