Hydride

This article is about binary compounds of hydrogen with another element. For the anion of hydrogen, see Hydrogen anion.

In chemistry, a hydride is formally the anion of hydrogen (H−), a hydrogen atom with two electrons.[1] In modern usage, this is typically only used for ionic bonds, but it is sometimes (and more frequently in the past) been applied to all compounds containing covalently bound H atoms. In this broad and potentially archaic sense, water (H2O) is a hydride of oxygen, ammonia is a hydride of nitrogen, etc. In covalent compounds, it implies hydrogen is attached to a less electronegative element. In such cases, the H centre has nucleophilic character, which contrasts with the protic character of acids. The hydride anion is very rarely observed.

Sodium hydride as an example of hydride salt

Almost all of the elements form binary compounds with hydrogen, the exceptions being He,[2] Ne,[3] Ar,[4] Kr,[5] Pm, Os, Ir, Rn, Fr, and Ra.[6][7][8][9] Exotic molecules such as positronium hydride have also been made.

  1. ^ "hydron (H02904)". IUPAC. 24 February 2014. doi:10.1351/goldbook.H02904. Retrieved 11 May 2021.
  2. ^ Helium hydride exists as an ion.
  3. ^ Neonium is an ion, and the HNe excimer exists also.
  4. ^ Argonium exists as an ion.
  5. ^ Kryptonium ion exist as a cation.
  6. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the elements (2nd ed.). Boston, Mass: Butterworth-Heinemann. ISBN 0-7506-3365-4. OCLC 48138330.
  7. ^ Lee, J.D. (2008). Concise Inorganic Chemistry (5th ed.). Wiley. ISBN 978-81-265-1554-7.
  8. ^ Massey, A.G. (2000). Main Group Chemistry. Inorganic Chemistry. Wiley. ISBN 978-0-471-49039-5.
  9. ^ Cite error: The named reference redbook2005 was invoked but never defined (see the help page).