Crystal Engineering under Hydrothermal Conditions: Cocrystals and Reactions of 3-Cyanopyridine with Glutaric Acid

Crystallization under hydrothermal conditions is an interesting method to selectively influence crystallization pathways and processes. Crystallization of 3-cyanopyridine and glutaric acid from aqueous solutions under ambient conditions leads to the 2:1 cocrystalline entity 1 of 3-cyanopyridine and glutaric acid. Crystallizations under thermal and hydrothermal conditions lead, depending on the amounts of water used, to both the polymorphic forms 1 and 2 of the 2:1 cocrystalline entity of 3-cyanopyridine and glutaric acid and furthermore to the cocrystalline entity nicotinamide and glutaric acid.