Caesium monoxide
 Caesium cations, Cs+ Oxide anions, O2− | |
| Names | |
|---|---|
| IUPAC name
Caesium oxide
| |
| Other names
Cesium oxide (US)
| |
| Identifiers | |
3D model (JSmol)
|
|
| ChemSpider | |
| EC Number |
|
PubChem CID
|
|
| |
| |
| Properties | |
| Cs2O | |
| Molar mass | 281.810 g·mol−1 |
| Appearance | Yellow-orange solid |
| Density | 4.65 g/cm3, solid |
| Melting point | 490 °C (914 °F; 763 K) (under N2) |
| Reacts to form CsOH | |
| 1534.0·10−6 cm3/mol | |
| Structure | |
| anti-CdCl2 (hexagonal) | |
| Thermochemistry | |
Heat capacity (C)
|
76.0 J/(K·mol) |
Std molar
entropy (S⦵298) |
146.9 J/(K·mol) |
Std enthalpy of
formation (ΔfH⦵298) |
−345.8 kJ/mol |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
|
Corrosive |
| GHS labelling: | |
 
| |
| NFPA 704 (fire diamond) | <imagemap>
File:NFPA 704.svg|80px|alt=NFPA 704 four-colored diamond poly 150 150 300 300 150 450 0 300 Health 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gas poly 300 0 450 150 300 300 150 150 Flammability 0: Will not burn. E.g. water poly 450 150 600 300 450 450 300 300 Instability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorus poly 300 300 450 450 300 600 150 450 Special hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid desc none </imagemap> |
| Flash point | non-flammable |
| Related compounds | |
Other anions
|
|
Other cations
|
|
Related compounds
|
Caesium hydroxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Caesium monoxide or caesium oxide is a chemical compound with the chemical formula Cs2O. It is the simplest and most common oxide of the caesium. It forms yellow-orange hexagonal crystals.[1]
Uses
Caesium oxide is used in photocathodes to detect infrared signals in devices such as image intensifiers, vacuum photodiodes, photomultipliers, and TV camera tubes[3] L. R. Koller described the first modern photoemissive surface in 1929–1930 as a layer of caesium on a layer of caesium oxide on a layer of silver.[4] It is a good electron emitter; however, its high vapor pressure limits its usefulness.[5]
Reactions
Elemental magnesium reduces caesium oxide to elemental caesium, forming magnesium oxide as a side-product:[6][7]
- Cs2O + Mg → 2 Cs + MgO
Cs2O is hygroscopic, forming the corrosive CsOH on contact with water.
References
- ^ 1.0 1.1 Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. pp. 451, 514. ISBN 0-8493-0487-3..
- ^ Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. pp. 97–100. ISBN 978-0-08-022057-4..
- ^ Capper, Peter; Elliott, C. T. (2000), Infrared Detectors and Emitters, Springer, p. 14, ISBN 978-0-7923-7206-6
- ^ Busch, Kenneth W.; Busch, Marianna A. (1990), Multielement Detection Systems for Spectrochemical Analysis, Wiley-Interscience, p. 12, ISBN 978-0-471-81974-5
- ^ Boolchand, Punit, ed. (2000), Insulating and Semiconducting Glasses, World Scientific, p. 855, Bibcode:2000isg..book.....B, ISBN 978-981-02-3673-1
- ^ Turner Jr., Francis M., ed. (1920), The Condensed Chemical Dictionary, New York: Chemical Catalog Co., p. 121
- ^ Arora, M.G. (1997), S-Block Elements, New Delhi: Anmol Publications, p. 13, ISBN 978-81-7488-562-3