The high-pressure structural behaviour of form I of 2,2,2-trifluoroethanol

In the crystaline state, mono-alcohols (R-OH) ideally form hydrogen bonds. However, competition from a comparatively bulky R group can force the hydrogen bond motif to change from a relatively straightforward chain structure to dimer, trimer and even larger catemeric rings. We have been carrying out a series of studies on the high-pressure and low-temperature structures of monoalcohols to establish structural trends on alteration of the R group. Our most recent studies have been on the monoalcohol 2,2,2-trifluoroethanol (TFE) which exhibit a rich polymorphism at low temperature and high-pressure. So far, we have conducted high-pressure structure determinations at room temperature on compression of TFE from the liquid. Here we propose to compress the low temperature form-I phase to establish both its compressibility and whether there are any transitions to the previously observed phases.