Crystallographic and Pressure-Temperature State Diagram Approach for the Phase Behavior and Polymorphism Study of Glutaric Acid

The two known polymorphs of glutaric acid were studied from a crystallographic and a thermal point of view. The crystal structure of the alpha phase was determined by means of X-ray powder diffraction experiments at 75 degrees C. The relative stability of both solid phases was established as a function of temperature and pressure. The thus-obtained state diagram indicates that the diacid exhibits an enantiotropic and a monotropic behavior at low and high pressure, respectively.