Hydrogen anion
| Names | |
|---|---|
| Systematic IUPAC name
Hydride[1] | |
| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChemSpider | |
| 14911 | |
PubChem CID
|
|
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| H− | |
| Molar mass | 1.00794 g mol−1 |
| Thermochemistry | |
Std molar
entropy (S⦵298) |
108.96 J K−1 mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
The hydrogen anion is a negative ion of hydrogen, H−. The hydrogen anion is an important constituent of the atmosphere of stars, such as the Sun. In chemistry, this ion is called hydride.
Occurrence
The hydrogen anion is the dominant absorber of photons in the interstellar medium. It absorbs energies in the range 0.75–4.0 eV, which ranges from the infrared into the visible spectrum (Rau 1999, Srinivasan 1999). It also occurs in the Earth's ionosphere (Rau 1999).
Its existence was first proven theoretically by Hans Bethe in 1929 (Bethe 1929). H− is unusual because, in its free form, it has no bound excited states, as was finally proven in 1977 (Hill 1977). It has been studied experimentally using particle accelerators (Bryant 1977).
In chemistry, the hydride anion is hydrogen that has the oxidation state −1. Hydride compounds formally contain a hydrogen anion. Most such compounds are in fact rather covalent. An example of a hydride is borohydride (BH−
4).
Sources and references
- Bethe, H. (1929). Z. Phys. 57: 815. Bibcode:1929ZPhy...57..815B. doi:10.1007/BF01340659.
{{cite journal}}: Invalid|ref=harv(help); Missing or empty|title=(help) - Bryant, H. C. (1977). Phys. Rev. Lett. 38: 228. Bibcode:1977PhRvL..38..228B. doi:10.1103/PhysRevLett.38.228.
{{cite journal}}: Invalid|ref=harv(help); Missing or empty|title=(help) - Hill, R. N. (1977). Phys. Rev. Lett. 38: 643. Bibcode:1977PhRvL..38..643H. doi:10.1103/PhysRevLett.38.643.
{{cite journal}}: Invalid|ref=harv(help); Missing or empty|title=(help) - Rau, A. R. P. (1996). "The Negative Ion of Hydrogen" (PDF). J. Astrophys. Astr. 17: 113.
{{cite journal}}: Invalid|ref=harv(help) - Rau, A. (1999). The Negative Ion of Hydrogen.
{{cite book}}: Invalid|ref=harv(help) - Srinivasan, G. (1999). "Chapter 5". From White Dwarfs to Black Holes: The Legacy of S. Chandrasekhar. Chicago: University of Chicago Press.
{{cite book}}: Invalid|ref=harv(help)
See also
- Hydron (hydrogen cation)
- Electride, another very simple anion
- Hydrogen ion
References
- ^ "Hydride - PubChem Public Chemical Database". The PubChem Project. USA: National Center for Biotechnology Information.