Controlling supramolecular assembly using electronic effects.

Through systematic structural studies using custom designed probe molecules, it has been shown that the balance between hydrogen-bonds in the context of supramolecular chemistry and crystal engineering can be understood and guided by a semiquantitative thermodynamic assessment that integrates theoretical and experimental views of solution-based molecular recognition events. Although pKa values can be used for ranking hydrogen-bond donors/acceptors within a family of compounds, they do not offer reliable information when comparing different functional groups. However, against a backdrop of a simple electrostatic interpretation of hydrogen bonds coupled with a focus on the primary non-covalent interactions, molecular electrostatic potential surfaces can be employed for guiding the synthesis of binary- and ternary co-crystals with the desired connectivity and dimensionality.