dihydrogencontaining

Dihydrogen-containing refers to chemical species that include one or more dihydrogen units (H2) as part of their structure. The term is used to describe molecules or materials in which the H–H unit remains intact or is only partially activated, rather than merely containing hydrogen atoms bonded to other elements. This descriptor is common in coordination chemistry and materials science, where H2 can interact with a metal center or be incorporated into a lattice or storage medium.

In organometallic chemistry, dihydrogen ligands describe H2 bonded to a metal in a manner that preserves the H–H bond to some extent (often described as an η2-H2 ligand). Such dihydrogen complexes are frequently transient intermediates in catalytic cycles for hydrogenation, dehydrogenation, or hydride transfer, and their properties depend on the metal, ligands, and back-donation from the metal into the H2 σ* orbital.

In materials and energy contexts, dihydrogen-containing compounds include hydrogen storage materials and certain hydride forms that reversibly uptake H2. These systems are described as containing dihydrogen units when H2 is bound or intercalated rather than fully dissociated into protons and hydrides. The term emphasizes the presence of intact H2 during storage, release, or reaction steps.

Because dihydrogen-containing is not a standard IUPAC category, scientists often prefer more specific terms such as dihydrogen complex, H2 adduct, or hydrogen storage material.