Toward High-Yielding Supramolecular Synthesis: Directed Assembly of Ditopic Imidazoles/Benzimidazoles and Dicarboxylic Acids into Cocrystals via Selective O−H···N Hydrogen Bonds

The supramolecular reactions between symmetric ditopic imidazoles/benzimidazoles and a variety of aliphatic and aromatic dicarboxylic acids produced molecular cocrystals 1−8 in high yields. Despite variations in molecular shape and substituent groups on the ditopic bases, each structure contained infinite 1-D molecular chains held together by robust, primary O−H···N hydrogen bonds. Secondary C−H···O interactions existed within these motifs as well as between neighboring chains, and it seems that intra- and interchain interactions are of equal structural importance based upon an analysis of the metrics displayed by each set of interactions. This study demonstrates that neutral hydrogen-bond interactions between imidazole/benzimidazoles (acting as the acceptor sites) and carboxylic acids (acting as the donor sites) provide sufficient driving force for the directed assembly of a wide range of binary cocrystals.