Impact of pressure on a highly polymorphic compound, isonicotinamide

The solid state behaviour of isonicotinamide has been extensively characterised under ambient conditions. It possesses 6 polymorphs that have been access via changes to solvent, experimental conditions etc. This behaviour is, in part, due to the hydrogen bonding groups of the molecule, the amide and pyridine groups. These groups allow for different interaction of molecules leading to different behaviour. We have recently investigated one of these polymorphs (Form I) and shown that it possesses superelastic behaviour on application of pressure (~4 GPa) i.e. the shape of the crystal changes over the transition. Form I possesses different hydrogen bonding to the other forms hence in this proposal, we want to investigate the behaviour of three other polymorphs that share similar hydrogen bonding interactions (chain structure) but are different to Form I.