Hydride

The hydrogen anion ${\mathrm{H}}^{-}$, or a hydride equivalent transferred from a reagent with its bonding electron pair. Bonded hydride transfer does not imply freely solvated ${\mathrm{H}}^{-}$ is present.

A hydrogen ligand bonded to more than one skeletal centre. A B–H–B bridge in a borane is commonly represented as a three-centre two-electron bond; it is not two independent ordinary B–H single bonds.