Hydride

In chemistry, a hydride is the anion of hydrogen, H−, or more commonly it is a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, the hydrogen atom is bonded to a more electropositive element or groups. Compounds containing hydrogen bonded to metals or metalloids may also be referred to as hydrides. Common examples are ammonia (NH3), methane (CH4), ethane (C2H6) (or any other hydrocarbon), and Nickel hydride (NiH), used in NiMH rechargeable batteries. In chemistry, a hydride is the anion of hydrogen, H−, or more commonly it is a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, the hydrogen atom is bonded to a more electropositive element or groups. Compounds containing hydrogen bonded to metals or metalloids may also be referred to as hydrides. Common examples are ammonia (NH3), methane (CH4), ethane (C2H6) (or any other hydrocarbon), and Nickel hydride (NiH), used in NiMH rechargeable batteries. Almost all of the elements form binary compounds with hydrogen, the exceptions being He, Ne, Ar, Kr, Pm, Os, Ir, Rn, Fr, and Ra. Bonds between hydrogen and other elements range from highly to somewhat covalent. Some hydrides, e.g. boron hydrides, do not conform to classical electron-counting rules and the bonding is described in terms of multi-centered bonds, whereas the interstitial hydrides often involve metallic bonding. Hydrides can be discrete molecules, oligomers or polymers, ionic solids, chemisorbed monolayers, bulk metals (interstitial), or other materials. While hydrides traditionally react as Lewis bases or reducing agents, some metal hydrides behave as hydrogen-atom donors and act as acids.