Single-crystal structure determination further proved the identity of Co Terpy-RF and illustrated the key role of hydrophobic interactions in its aggregation in the solid state (Fig. , Table ). The complex prefers to stack in a manner that maximizes the perfluoro-perfluoro interactions on its side chains through the formation of fluorinated domains, i.e. hydrophobic pockets. At a macroscopic level, this is similarly manifested in a spontaneous crystallization into ordered ribbons that were on the order of several microns thick and tens of microns in length upon drying a solution of the complex on a solid substrate (Fig. ). The hydrophobicity of the Co Terpy-RF film was estimated through contact angle measurements, which yielded a value of 100.7°, corresponding to an overall hydrophobic character (Fig. ).