To generate the hemiaminal, Kawamichi et al. gently passed a solution of an aldehyde over an intact crystal of their coordination network in which an amine was tightly bound as a guest molecule.

One class has been dubbed ‘hemiaminal dynamic covalent networks’ (HDCNs), formed by a reaction between paraformaldehyde and 4,4ʹ-oxydianiline (ODA). After heating to drive off trapped solvent and ...