Caesium monoxide
 Cs+ Oxide anions, O2− | |
| Names | |
|---|---|
| IUPAC name Caesium oxide | |
| Other names Cesium oxide (US) | |
| Identifiers | |
CAS Number |
|
3D model (JSmol) |
|
| ChemSpider |
|
| ECHA InfoCard | 100.039.693  |
| EC Number |
|
PubChem CID |
|
InChI
| |
| |
| Properties | |
Chemical formula | 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) |
Solubility in water | Reacts to form CsOH |
Magnetic susceptibility (χ) | 1534.0·10−6 cm3/mol |
| Structure | |
Crystal 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: | |
Pictograms |   |
| NFPA 704 (fire diamond) |  3 0 2 W |
| 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).  Y verify (what is  Y N ?) Infobox references | |
Chemical compound
Caesium monoxide or caesium oxide is an 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
- ^ a b 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
- v
- t
- e
