Molecular capsule constructed by multiple hydrogen bonds: self-assembly of cavitand tetracarboxylic acid with 2-aminopyrimidine

Two molecules of cavitand tetracarboxylic acid and four molecules of 2-aminopyrimidine assemble into a capsule via 16 hydrogen bonds, as shown by H-1 NMR titration and X-ray crystallographic analysis; in the solid state, two molecules of nitrobenzene are encapsulated in the capsule.