Pyridine Directed Assembly of Di-<i>O</i>-Alkyl-tris-<i>p</i>-Carboxylatocalix[4]arenes

Crystallization of four di-O-alkyl-tris-p-carboxylatocalix­[4]­arenes from a series of pyridine derivatives has been carried out to investigate the effect of introducing alkyl groups around the pyridine guest/template. Where single crystals were obtained, for 12 of 24 possible structures, in all but one case the calixarenes assemble with the pyridine derivative into hydrogen-bonded head-to-head dimers within extended bilayer or nanotubular arrays.