Synthetic recognition motifs of Supramolecular Chemistry

The pi-pi charge-transfer interactions of bipyridinium with dioxyarenes or diaminoarenes have been used extensively for the construction of mechanically interlocked systems and in crystal engineering.
The use of crown ether binding with metal or ammonium cations is ubiquitous in supramolecular chemistry.
The formation of carboxylic acid dimers and other simple hydrogen bonding interactions.
The complexation of bipyridines or tripyridines with ruthenium, silver or other metal ions is of great utility in the construction of complex architectures of many individual molecules.
The complexation of porphyrins or phthalocyanines around metal ions gives access to catalytic, photochemical and electrochemical properties as well as complexation. These units are used a great deal by nature.