Self-assembly of rectangles via building units bearing salen and oxazoline ligands

Rigid spacer-chelator with the framework of 3 has been prepared. Building units with two parallel coordination sites such as salen and oxazoline units have also been synthesized. The spacer-chelators, 11 and 15, readily self-assembled with metal complexes such as Zn++ and Co++ to form molecular rectangles. The overall dimensions of the rectangles, 13 and 17, are 6.2 Å × 23.5 Å. The characterization of the supramolecules by NMR, mass spectroscopy, and X-ray crystal structures is also reported.