New phase transition of p-cresol studied by DSC analysis and FT-IR spectroscopy.

We have investigated polymorphism in p-cresol using the FT-IR spectroscopy and differential scanning calorimetry. The present results show that in addition to the well-known two crystalline phases of p-cresol, which melts at 307.6 and 309.2 K, we discovered the existence of a new crystalline phase, which melts at 302.9 K. For the first time we have received the FT-IR spectra of three polymorphs and their temperature dependencies in the region 300-12 K. Comparison between the FT-IR spectra of three polymorphs shows that they are completely different.