Heterometallic

Heterometallic refers to chemical systems in which the metal centers are composed of at least two different metallic elements. In contrast, homometallic compounds contain metal centers of a single element. The term is widely used in inorganic, organometallic, and materials chemistry to describe discrete molecules, clusters, coordination polymers, and extended solids that incorporate two or more distinct metals.

Structural types include multinuclear coordination complexes with mixed metal centers (for example, Fe–Cu or Mo–Fe), heterometallic clusters, and metal–organic frameworks or inorganic frameworks that incorporate different metals in separate nodes or mixed-occupancy sites. Heterometallic systems can also arise in polynuclear clusters where different metals occupy defined positions and interact magnetically or electronically, influencing properties such as redox behavior, catalysis, and magnetism.

Synthesis and design strategies emphasize selective incorporation of different metals into a single framework or cluster. Approaches include stepwise assembly using pre-formed metal fragments, transmetalation between metal precursors, one-pot reactions with complementary metals, and templated or directed assembly by ligands that favor distinct metals. Controlling stoichiometry, metal distribution, and site selectivity remains a central challenge.

Properties and applications are often enhanced by the presence of multiple metals. Heterometallic systems can exhibit tunable redox potentials, cooperative catalysis, enhanced magnetic coupling, and unique optical or electronic features.Applications span catalysis (electrocatalysis, small-molecule activation), energy storage and conversion, magnetic materials, luminescent materials, and catalysis-driven synthesis. The term highlights the deliberate combination of different metal elements to achieve properties not accessible in single-metal systems.