ditopic

Ditopic is an adjective used in chemistry to describe molecules, ligands, or receptors that have two distinct binding sites capable of engaging with two targets simultaneously. In coordination chemistry, a ditopic ligand contains two donor sites that can coordinate to two metal centers or bridge a dinuclear or higher-nuclear assembly. The two sites may be identical or different in donor type and can be connected by a spacer that controls the geometry and distance between the binding ends.

Ditopic ligands are related to, but distinct from, other denticity concepts. They are often discussed alongside monodentate and multidentate (such as bidentate or polydentate) ligands, but the emphasis in the term ditopic is the presence of two addressable binding sites that can interact with two separate coordination environments or two recognition events. In many cases, ditopic ligands are designed to bridge two metal centers, enabling the formation of dinuclear complexes, supramolecular assemblies, or metal-organic frameworks. They can also function as ditopic receptors, with two recognition elements that cooperate to bind a single guest or two different guests.

Applications of ditopic designs include catalysis with cooperative active sites, materials chemistry for constructing extended networks, and sensing or separation technologies where simultaneous dual interactions enhance selectivity. The term is used across inorganic, organometallic, and supramolecular chemistry to emphasize the presence and dual functionality of the lip binding sites.