Unveiling the Role of Macrodipolar Interactions in the Properties of Self-Assembled Supramolecular Materials.

Self-assembling of supramolecules composed of benzene and cyclohexane tricarboxamide derivatives can form highly organized 1 D fibers exhibiting macrodipoles. The way fibers pack in the condensed phase governs the final properties of the supramolecular material, in which macrodipoles can be oriented parallel or antiparallel to each other, and their magnitude can be tuned by additional intra-columnar dipole stabilization. X-ray structural elucidation of these materials remains a real challenge due to the difficulty in growing single crystals. This problem can be tackled by using atomistic molecular dynamics to simulate supramolecular materials composed of cyclohexanetricarboxamide derivatives assuming different magnitudes and orientations of macrodipoles in the condensed phase, as we show here. The results provide insight on the isotropization mechanism of the supramolecules and also reveal that the relative orientation between macrodipoles can indeed influence their stability. This work nicely complements X-ray structural characterizations of supramolecular materials, and helps understand structure-property relationships of a range of similar noncovalent materials.