caesium superoxide
{{Chembox
| ImageFile = Kristallstruktur Bariumperoxid.png
| ImageCaption = {{legend|rgb(224,224,224)|Caesium cations, {{chem2|Cs+}}}}{{legend|red|Superoxide anions, {{chem2|O2−}}}}
|Section1={{Chembox Identifiers
| CASNo = 12018-61-0
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem =
| ChemSpiderID =
| InChI=1S/Cs.HO2/c;1-2/h;1H/q+1;/p-1
| InChIKey=DZWLBLJPRRQKGB-UHFFFAOYSA-M
| SMILES =[Cs+].[O-] [O]
}}
| Section2={{Chembox Properties
| Appearance = Yellow to orange solid
| Cs=1|O=2
| Density = 3.77 g/cm3[http://www.webelements.com/compounds/caesium/caesium_superoxide.html Caesiumhyperoxid bei webelements.com.]
| BoilingPt =
| Solubility = reacts
}}
|Section8={{Chembox Related
| OtherCations={{ubl|Lithium superoxide|Sodium superoxide|Potassium superoxide|Rubidium superoxide}}
| OtherAnions={{ubl|Caesium oxide|Caesium peroxide}}
}}
}}
Caesium superoxide is a chemical compound with the chemical formula {{chem2|CsO2}}. It consists of caesium cations {{chem2|Cs+}} and superoxide anions {{chem2|O2−}}. It is an orange solid.
Preparation
Burning caesium in excess oxygen will produce caesium superoxide.
:{{chem2|Cs + O2 → CsO2}}
Properties
Caesium superoxide's crystal structure is same as calcium carbide. It contains direct oxygen-oxygen bonding.
It reacts with water to form hydrogen peroxide and caesium hydroxide.
:{{chem2|2 CsO2 + 2 H2O → O2↑ + H2O2 + 2 CsOH}}
Heating to approximately 400 °C induces thermal decomposition to caesium peroxide.{{cite journal | last1=Berardinelli | first1=S. P. | last2=Kraus | first2=D. L. | title=Thermal decomposition of the higher oxides of cesium in the temperature range 320-500.deg. | journal=Inorganic Chemistry | publisher=American Chemical Society (ACS) | volume=13 | issue=1 | date=1974-01-01 | issn=0020-1669 | doi=10.1021/ic50131a037 | pages=189–191}}
The standard enthalpy of formation ΔHf0 of caesium superoxide is −295 kJ/mol.{{cite book | last=Holleman | first=Arnold | title=Anorganische ChemienBand 1 | publisher=de Gruyter | publication-place=Berlin | year=2017 | isbn=978-3-11-049585-0 | oclc=968134975 | language=de}}
Caesium superoxide reacts with ozone to form caesium ozonide.
:{{chem2|CsO2 + O3 → CsO3 + O2}}