Gelation Landscape Engineering Using a Multi-Reaction Supramolecular Hydrogelator System

Simultaneous
control of the kinetics and thermo­dynamics of
two different types of covalent chemistry allows pathway selectivity
in the formation of hydro­gelating molecules from a complex reaction
network. This can lead to a range of hydrogel materials with vastly
different properties, starting from a set of simple starting compounds
and reaction conditions. Chemical reaction between a tri­aldehyde
and the tuberculosis drug iso­niazid can form one, two, or three
hydrazone connectivity products, meaning kinetic gelation pathways
can be addressed. Simultaneously, thermo­dynamics control the
formation of either a keto or an enol tautomer of the products, again
resulting in vastly different materials. Overall, this shows that
careful navigation of a reaction landscape using both kinetic and
thermo­dynamic selectivity can be used to control material selection
from a complex reaction network.