Isonicotinamide self-association: the link between solvent and polymorph nucleation.

We show that, in a controlled and reproducible way, specific solvents lead to specific polymorphic forms of isonicotinamide. We argue on the basis of Raman and FTIR spectroscopy that the hydrogen bonding in solution kinetically drives the nucleation towards a specific form. This generally may lead to good understanding and control of polymorphism and crystal nucleation.