Supramolecular Alcohol–Amine Crystals and Their Hydrogen-Bond Patterns

Abstract

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.