Encapsulation of two aromatics by a carcerand-like capsule of nanometre-scale dimensions

Co-crystallization of C-methylcalix[4]resorcinarene 1 with 4,4′-bipyridine 2 in the presence of nitrobenzene 3 yields a six-component carcerand-like capsule, 2(1)·4(2), held together by 16 hydrogen bonds, in which two molecules of 3 are aligned within the interior of the complex in a head-to-head fashion.