**3. Nucleation and Crystal Growth**

Supramolecular synthons are defined as structural units within super-molecules which can be formed and/or assembled by known synthetic operations involving intermolecular interactions. Supramolecular synthons are spatial arrangements of intermolecular interactions. Therefore, the overall goal of crystal engineering is to recognise and design synthons that are robust enough to be interchanged between network structures [9]. The Cambridge Structural Database may be used to identify stable hydrogen bonding motifs with the ambition that the most robust motifs will remain intact across a family of related structures [61,62].
