Self-inclusion structure of 5,11,17,23-tetrakis(azidomethyl)-25,26,27,28-tetrahydroxycalix[4]arene, and 5,11,17,23-tetra-tert-butyl-25,27-bis(chloroacetoxy)-26,28-bis(2-pyridylmethoxy)calix[4]arene.

In the structures of the two title calix[4]arene derivatives, C(32)H(28)N(12)O(4), (I), and C(60)H(68)Cl(2)N(2)O(6), (II), compound (I) adopts an open-cone conformation in which there are four intramolecular O-H...O hydrogen bonds, while compound (II) adopts a distorted chalice conformation where the two pendant pyridyl rings, one of which is disordered, are almost mutually perpendicular, with an interplanar angle of 79.2 (2) or 71.4 (2) degrees . The dihedral angles between the virtual plane defined by the four bridging methylene C atoms and the phenol rings are 120.27 (7), 124.03 (6), 120.14 (8) and 128.25 (7) degrees for (I), and 95.99 (8), 135.93 (7), 97.21 (8) and 126.10 (8) degrees for (II). In the supramolecular structure of (I), pairs of molecules associate by self-inclusion, where one azide group of the molecule is inserted into the cavity of the inversion-related molecule, and the association is stabilized by weak intermolecular C-H...N hydrogen bonds and pi(N(3))-pi(aromatic) interactions. The molecular pairs are linked into a two-dimensional network by a combination of weak intermolecular C-H...N contacts. Each network is further connected to its neighbor to produce a three-dimensional framework via intersheet C-H...N hydrogen bonds. In the crystal packing of (II), the molecular components are linked into an infinite chain by intermolecular C-H...O hydrogen bonds. This study demonstrates the ability of calix[4]arene derivatives to form self-inclusion structures.