Cocrystallisation with carbon

While carbon is ubiquitous across organic synthesis and materials chemistry, in supramolecular chemistry the role of carbon as a target for the formation of directional interactions, such as hydrogen or halogen bonds, is less known and developed in comparison to nitrogen or oxygen. Here we provide a brief review of the opportunities for the design of multi-component crystals (cocrystals) based on the recognition of carbon-based moieties, notably non-substituted polycyclic aromatic hydrocarbons (PAHs), functionalities bearing single carbon atom recognition sites such as isonitriles or carbenes, as well as the molecules of the element carbon itself, such as fullerenes, with particular emphasis on halogen bonding and C-H⋯π interactions. By providing highlights of historical examples, as well as select recent advances including applications oriented towards carbon nanomaterials, this review illustrates the role of carbon in cocrystallisation and solid-state supramolecular chemistry, from fundamental research and materials design, to biomolecular recognition and extraterrestrial geology.