Caesium peroxide

Caesium peroxide
Names

IUPAC name Caesium peroxide
Identifiers
CAS Number	12053-70-2
Properties
Chemical formula	Cs₂O₂
Molar mass	297.809 g·mol⁻¹
Appearance	Yellowish^[1]
Structure
Crystal structure	Orthorhombic^[2]
Related compounds
Other cations	Lithium peroxide Sodium peroxide Potassium peroxide Rubidium peroxide
Related caesium oxides	Caesium suboxide Caesium monoxide Caesium sesquioxide Caesium superoxide Caesium ozonide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

Caesium peroxide or cesium peroxide is an inorganic compound of caesium and oxygen with the chemical formula Cs₂O₂. It can be formed from caesium metal by adding a stoichiometric amount in ammonia solution, or oxidizing the solid metal directly.^[1]

2 Cs + O₂ → Cs₂O₂

It can also be formed by the thermal decomposition of caesium superoxide:^[3]

2 CsO₂ → Cs₂O₂ + O₂

Upon heating until 650 °C, the compound will decompose to caesium monoxide and atomic oxygen:^[4]

Cs₂O₂ → Cs₂O + [O]

Caesium peroxide shows a Raman vibration at 743 cm⁻¹, due to the presence of the peroxide ions.^[5] The compound is often used as a coating for photocathodes, due to its low work function.^[6]

References

^ ^a ^b I. I. Volnov (2012). Peroxides, Superoxides, and Ozonides of Alkali and Alkaline Earth Metals. Springer. p. 45. ISBN 9781468482522.
^ Band, A.; Albu-Yaron, A.; Livneh, T.; Cohen, H.; Feldman, Y.; Shimon, L.; Popovitz-Biro, R.; Lyahovitskaya, V.; Tenne, R. (2004-07-27). "Characterization of Oxides of Cesium". The Journal of Physical Chemistry B. 108 (33). American Chemical Society (ACS): 12360–12367. doi:10.1021/jp036432o. ISSN 1520-6106.
^ Berardinelli, S. P.; Kraus, D. L. (1974-01-01). "Thermal decomposition of the higher oxides of cesium in the temperature range 320-500.deg". Inorganic Chemistry. 13 (1). American Chemical Society (ACS): 189–191. doi:10.1021/ic50131a037. ISSN 0020-1669.
^ Zefirov, Nikolaj (1995). Chimičeskaja ėnciklopedija : v pjati tomach (in Bosnian). Moskva: Izdat. p. 658. ISBN 5-85270-092-4. OCLC 258155382.
^ Livneh, Tsachi; Band, Alisa; Tenne, Reshef (2002). "Raman scattering from the peroxide ion in Cs₂O₂". Journal of Raman Spectroscopy. 33 (8). Wiley: 675–676. Bibcode:2002JRSp...33..675L. doi:10.1002/jrs.900. ISSN 0377-0486.
^ Sun, Yun; Liu, Zhi; Pianetta, Piero; Lee, Dong-Ick (2007). "Formation of cesium peroxide and cesium superoxide on InP photocathodes activated by cesium and oxygen". Journal of Applied Physics. 102 (7). AIP Publishing: 074908–074908–6. Bibcode:2007JAP...102g4908S. doi:10.1063/1.2786882. ISSN 0021-8979.