This article describes the use of antisolvent addition at high-pressure to aid precipitation and recovery of high-pressure phases to ambient pressure. Paracetamol (PCM) was used as a model system to demonstrate the principle due to the extensive literature of paracetamol at high-pressure and ambient pressure. We have observed that we are able to recover the orthorhombic form of paracetamol to ambient pressure using this technique, although solvent-mediated transformations are a hurdle. During this investigation we observed a new methanol solvate of paracetamol that is similar in structure to the known form. The methanol solvate is stable to 0.2 GPa before transformation to the orthorhombic form that is known to be the stable form at high pressure.
- This article is part of the themed collection: The effects of extreme conditions on molecular solids