Figure 1
The pressure dependence of (a) unit-cell volume, molecular volume, and compressibility, as well as, (b) unit-cell parameters for BZC polymorphs (I) (circles) and (IV) (triangles). Unit-cell parameters for BZC polymorphs (II) (at 300 K, squares) and (III) (at 150 K, diamonds) have been included for comparison. Unit-cell volume and parameter b for polymorph (III) have been divided by two. High-pressure data collected for sample in MeOH:EtOH:H2O 16:3:1 volume hydrostatic medium is marked with full symbols, while open symbols mark data collected with the use of DMSO as a hydrostatic medium. Trend lines were extended beyond data points as dashed lines to mark pressure regions where the form of BZC crystals was preserved on compression [polymorph (I)] or decompression [polymorph (IV)]. |