Polymorphism in phenol under pressure: The volume compressibilities of phenol I and II at 10°C, and the phase diagram below 0°C

The volume compression and compressibility of polycrystalline phenol I and II at 10°C are presented up to 3000 bar. The phenol I-II transition below 0°C has been studied for thin samples in a parallel-plate dielectric cell. Phenol II cannot be prepared from phase I below about 1400 bar, and at 1 bar phase II reverts to phase I at −49°C.