Supramolecular Alcohol-Amine Crystals and Their Hydrogen-Bond Patterns

An analysis of the structures of five new cocrystals with saturated hydrogen bonding between amines and alcohols is presented. These five are all cocrystals with p-phenylenediamine (PDA) and a mono- or diol. The cocrystals are p-phenylenediamine-phenol (1/2) [PDA·2 phenol, (I)], p-phenylenediamine-p-phenylphenol (1/2) [PDA·2 p-phenylphenol (II)], p-phenylenediamine-2,6-dihydroxynaphthalene (1/1) [PDA·2,6-dihydroxynaphthalene (III)], p-phenylenediamine-1,6-hexanediol (1/1) [PDA·1,6-hexanediol (IV)] and p-phenylenediamine-p-chlorophenol (1/2) [PDA·2 p-chlorophenol (V)]. These crystals have two distinctly different supramolecular hydrogen-bond patterns, when considering only the hydroxyl and amine groups. There are, in addition, variations in the ways covalently bonded crosslinks connect these hydrogen-bond networks. The graph sets of the hydrogen-bond networks of these and other published saturated amine-alcohol crystals are compared and suggestions made on how to present the graph-set descriptions, especially those involving infinite two- and three-dimensional networks of intersecting chains which are characteristic of most of these materials.