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.