Designing nanoporous crystalline materials by self-assembly: 2D hydrogen-bonded networks from upper rim calix[4]arene diamide derivatives

The self-assembly properties in the solid state of tectons derived from the reaction of calix[4]arene aminomethyl derivatives with a carboxylic acid or a protected amino acid are described, along with their conformational properties in solution. The X-ray crystal structures show that these compounds self-assemble in the lattice through a network of hydrogen-bonds between the amide groups, which overall results in infinite nanotubes formed by the calixarene aromatic cavities. Small changes in the upper rim substituents do not disturb the basic self-assembly motif which appears general and quite useful for controlling crystal growth by design and obtaining novel nanoporous crystalline materials.