Chemistry:Rubidium superoxide
| Names | |
|---|---|
| Other names
Rubidium hyperoxide
| |
| Identifiers | |
3D model (JSmol)
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|
| |
| |
| Properties | |
| RbO 2 | |
| Molar mass | 117.466 g·mol−1 |
| Appearance | Bright yellow[1] |
| Structure | |
| Distorted CaC 2 structure[2] | |
| Related compounds | |
Other cations
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Rubidium superoxide or rubidium hyperoxide is a chemical compound with the chemical formula RbO
2. In terms of oxidation states, the negatively charged superoxide and positively charged rubidium give it a structural formula of Rb+
[O
2]−
.[2]
Chemistry
It can be created by slowly exposing elemental rubidium to oxygen gas:[3]
- Rb(s) + O
2(g) → RbO
2(s)
Like other alkali metal hyperoxides, crystals can also be grown in liquid ammonia.[4]
Between 280 and 360 °C, Rubidium superoxide will decompose, leaving not rubidium sesquioxide (Rb
2O
3), but rather rubidium peroxide (Rb
2O
2).[3]
- 2 RbO
2(s) → Rb
2O
2(s) + O
2(g)
An even more oxygen rich compound, that of rubidium ozonide (RbO
3) can be created using RbO
2.[5]
Properties
Roughly speaking, RbO
2 has a crystal structure similar to tetragonal calcium carbide, but is rather distorted due to the Jahn–Teller effect, which makes the crystal structure less symmetrical.[2]
RbO
2 is stable in dry air, but is extremely hygroscopic.[3]
The compound has been studied as an example of magnetism arising intrinsically from the p-shell.[6] RbO
2 has been predicted to be a paramagnetic Mott insulator.[7] At low temperatures, it transitions to antiferromagnetic order, with a Neel temperature of 15 K.[2]
See also
References
- ↑ Astuti, Fahmi; Miyajima, Mizuki; Fukuda, Takahito; Kodani, Masashi; Nakano, Takehito; Kambe, Takashi; Watanabe, Isao (2019). "Synthesis and Characterization of Magnetic Rubidium Superoxide, RbO2". Materials Science Forum (Trans Tech Publications, Ltd.) 966: 237–242. doi:10.4028/www.scientific.net/msf.966.237. ISSN 1662-9752.
- ↑ 2.0 2.1 2.2 2.3 Labhart, M.; Raoux, D.; Känzig, W.; Bösch, M. A. (1979-07-01). "Magnetic order in 2p-electron systems: Electron paramagnetic resonance and antiferromagnetic resonance in the alkali hyperoxides KO2, RbO2, and CsO2". Physical Review B (American Physical Society (APS)) 20 (1): 53–70. doi:10.1103/physrevb.20.53. ISSN 0163-1829.
- ↑ 3.0 3.1 3.2 Kraus, D. L.; Petrocelli, A. W. (1962). "The Thermal Decomposition of Rubidium Superoxide". The Journal of Physical Chemistry (American Chemical Society (ACS)) 66 (7): 1225–1227. doi:10.1021/j100813a003. ISSN 0022-3654.
- ↑ Busch, G., ed (1974). "Magnetische und kalorische Eigenschaften von Alkali-Hyperoxid-Kristallen". Physics of Condensed Matter. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 267–291. doi:10.1007/978-3-662-39595-0. ISBN 978-3-662-38713-9.
- ↑ Vol'nov, I. I.; Dobrolyubova, M. S.; Tsentsiper, A. B. (1966). "Synthesis of rubidium ozonide via rubidium superoxide". Bulletin of the Academy of Sciences, USSR Division of Chemical Science (Springer Science and Business Media LLC) 15 (9): 1611–1611. doi:10.1007/bf00848934. ISSN 0568-5230.
- ↑ Kováčik, Roman; Ederer, Claude (2009-10-26). "Correlation effects in p-electron magnets: Electronic structure of RbO2 from first principles". Physical Review B (American Physical Society (APS)) 80 (14): 140411. doi:10.1103/physrevb.80.140411. ISSN 1098-0121.
- ↑ Kováčik, Roman; Werner, Philipp; Dymkowski, Krzysztof; Ederer, Claude (2012-08-17). "Rubidium superoxide: A p-electron Mott insulator". Physical Review B (American Physical Society (APS)) 86 (7): 075130. doi:10.1103/physrevb.86.075130. ISSN 1098-0121.
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