Caesium carbonate[1]
IUPAC name Caesium carbonate
Other names Cesium carbonate
Identifiers
CAS number	534-17-8 Y
PubChem	10796
ChemSpider	10339 Y
EC-number	208-591-9
Jmol-3D images	Image 1
SMILES [Cs+].[Cs+].[O-]C([O-])=O
InChI InChI=1S/CH2O3.2Cs/c2-1(3)4;;/h(H2,2,3,4);;/q;2*+1/p-2 Y Key: FJDQFPXHSGXQBY-UHFFFAOYSA-L Y InChI=1/CH2O3.2Cs/c2-1(3)4;;/h(H2,2,3,4);;/q;2*+1/p-2 Key: FJDQFPXHSGXQBY-NUQVWONBAO
Properties
Molecular formula	Cs2CO3
Molar mass	325.82 g/mol
Appearance	white powder
Density	4.072 g/cm3
Melting point	610 °C (decomp.)
Solubility in water	2605 g/L (15 °C)
Solubility in ethanol	110 g/L
Solubility in DMF	119.6 g/L
Solubility in DMSO	361.7 g/L
Solubility in Sulfolane	394.2 g/L
Solubility in NMP	723.3 g/L
Hazards
EU Index	not listed
Flash point	non-flammable
Related compounds
Other anions	Caesium bicarbonate
Other cations	Lithium carbonate Sodium carbonate Potassium carbonate Rubidium carbonate
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Caesium carbonate (or cesium carbonate in the US) is a white crystalline solid compound.^[2] Caesium carbonate has a high solubility in polar solvents such as water, alcohol, Et₂O, and DMF. Its solubility is higher in organic solvents compared to other carbonates like potassium carbonate. It is important base for organic chemistry to synthesize various compounds. Caesium carbonate is insoluble in most other organic solvents such as toluene, p-xylene, and chlorobenzene.

  For energy conversion

^[3] There is a huge growing desire in caesium and its compounds for energy conversion devices such as magneto-hydrodynamic generators, thermionic emitters, and fuel cells. Relatively effective polymer solar cells are built by thermal annealing of caesium carbonate. Caesium carbonate increases the energy effectiveness of the power conversion of solar cells and enhances the life times of the equipment.^[2] The studies done on UPS and XPS reveal that the system will do less work due to the thermal annealing of the Cs₂CO₃ layer. Caesium carbonate breaks down into Cs₂O and Cs₂O₂ by thermal evaporation. It was suggested that, when Cs₂O combines with Cs₂O₂ they produce n-type dopes that supplies additional conducting electrons to the host devices. This produces a highly efficient inverted cell that can be used to further improve the efficiency of polymer solar cells or to design adequate multijunction photovoltaic cells.^[4] The nanostructure layers of Cs₂CO₃ can be used as cathodes for organic electronic materials due to its capacity to increase the kinetic energy of the electrons. The nanostructure layers of caesium carbonate had been probed for various fields using different techniques. The fields include such as photovoltaic studies, current-voltage measurements,UV photoelectron spectroscopy, X-ray photoelectron spectroscopy, and impedance spectroscopy. The n-type semiconductor produced by thermal evaporation of Cs₂CO₃ reacts intensively with metals like Al, and Ca in the cathode. This reaction will cut down the work the cathode metals.^[5] Polymer solar cells based on solution process are under extensive studies due to their advantage in producing low cost solar cells. Lithium fluoride has been used to raise the power conversion efficiency of polymer solar cells. However, it requires high temperatures (> 500 degree), and high vacuum states raise the cost of production. The devices with Cs₂CO₃ layers have produced equivalent power conversion efficiency compared with the devices that use lithium fluoride.^[2] Placing a Cs₂CO₃ layer in between the cathode and the light-releasing polymer improvers the efficiency of the white light emission emitting diode.

  Synthesis

^[3] Caesium carbonate can be prepared by thermal decomposition of caesium oxalate. Upon heating caesium oxalate is converted to caesium carbonate and carbon monoxide is released: Cs₂C₂O₄ -> Cs₂CO₃ + CO^[3] It can also be synthesized by reacting Caesium hydroxide with carbon dioxide. 2CsOH + CO₂ -> Cs₂CO₃ + H₂O

  Chemical Reaction

^[6] Caesium carbonate is very important for the N-alkylation compounds such as sulfonamides, amines, b-lactams, indoles, heterocyclic compounds, 14N-Substituted aromatic imides, phthalimides, and several similar other compounds. A research on these compounds has focused on their synthesis and biological activity.^[7] In the presence of gold sodium chloride (NaAuCl₄) caesium carbonate is very efficient mechanism for aerobic oxidation of different kinds of alcohols into ketones and aldehydes at room temperature without additional polymeric compounds. There is no acid formation produced when primary alcohols are used.^[8] The process of selective oxidation of alcohols to carbonyls had been quite difficult due to the nucleophilic character of the carbonyl intermediate.^[7] In the past Cr(VI) and Mn(VII) reagents have been used to oxidize alcohols, however, these reagents are thought to be toxic to the environment, and are pricy. Caesium carbonate can also be used in Suzuki, Heck, and Sonogashira synthesis reactions. Caesium carbonate produces carbonylation of alcohols and carbamination of amines more efficiently than some of the mechanisms that have been introduced in the past.^[9] Caesium carbonate can be used for sensitive synthesis when a balanced strong base is needed.

  Caesium compound Salts

^[10] Weak caesium salts are important to the synthesis of important compounds such as phenol, sulfonamide, thiol, carboxylic acids and 1,3-dicarbonyl compounds. Caesium carbonate produces carbon dioxide whenever it comes in contact with stomach acids. The reaction produces caesium chloride, carbon dioxide and water. Cs₂CO₃ + 2HCl -> 2CsCl + CO₂ + H₂O

  Stability

Stability: stable under standard pressure and temperature.

  Material safety

Causes eye, skin and digestive tract irritations.

  Caesium

^[11] Many of the caesium carbonates properties comes form the caesium element. Caesium is a soft, ductile, alkali and liquid metal at 28.4°C. It is one of the most electropositive and the best reactive alkali metal. It forms various compounds with different anions and alloys as well as with other alkali metals and gold. The element ignites easily in the presence of air and produces explosive reactions in water. Caesium can be used for several purposes such as for television image devices, night-vision equipment, solar photovoltaic cells, and various types of other photoelectric cells.

  References

1. ^ Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. B-91. ISBN 0-8493-0462-8. .
2. ^ ^{a b c} Jinsong, Huang; Zheng Xu, and Yang Yang (2007). ₂CO₃.pdf "Low-Work-Function Surface Formed by Solution-Processed and Thermally Deposited Nanoscale Layers of Cesium Carbonate". ADVANCED FUNCTIONALS MATERIALS 17 (19). doi:10.1002/adfm.200700051. http://yylab.seas.ucla.edu/papers/AFM%20Cs₂CO₃.pdf. Retrieved 3/31/12. 
3. ^ ^{a b c} E. L. SIMONS, E. J. CAIRNS; L. D. SANGERMANO (1966). "Purification and preparation of some caesium compounds". image/png) 13 (2): 199. PMID 18959868. http://www.ncbi.nlm.nih.gov/pubmed/18959868. 
4. ^ Hua-Hstien, Liao; Li-Min Chen, Zheng Xu, Gang Li, and Yang Yang (2008). "Highly efficient inverted polymer solar cell by low temperature annealing of Cs₂CO₃ interlayer". APPLIED PHYSICS LETTERS 92 (17). doi:10.1063/1.2918983. http://yylab.seas.ucla.edu/papers/ApplPhysLett_92_173303.pdf. 
5. ^ Jen-Chun, Wang; Wei-Tse Weng,b Meng-Yen Tsai, Ming-Kun Lee, Sheng-Fu Horng, Tsong-Pyng Perng,Chi-Chung Kei, Chih-Chieh Yuc and Hsin-Fei Meng. "Highly efficient flexible inverted organic solar cells using atomic layer deposited ZnO as electron selective layer". Journal of Materials. 
6. ^ Mercedes, Escudero; Lautaro D. Kremenchuzky,a Isabel A. Perillo, Hugo Cerecetto, María Blanco (2010). "Efficient Cesium Carbonate Promoted N-Alkylations of Aromatic Cyclic Imides Under Microwave Irradiation". SYNTHESIS 4: 571. doi:10.1055/s-0030-1258398. http://www.organic-chemistry.org/abstracts/lit3/165.shtm. Retrieved 3/31/12. 
7. ^ ^{a b} Babak, Karimi; Frahad Kabiri Estanhani (2009). "Gold nanoparticles supported on Cs2CO3 as recyclable catalyst system for selective aerobic oxidation of alcohols at room temperaturew". The Royal Society of Chemistry 5556 (55). doi:10.1039/b908964k. http://pubs.rsc.org/en/content/articlepdf/2009/cc/b908964k. 
8. ^ Lie, Liand; Guodong Rao, Hao-Ling Sun, and Jun-Long Zhang (2010). "Aerobic Oxidation of Primary Alcohols Catalyzed by Copper Salts and Catalytically Active m-Hydroxyl-Bridged Trinuclear Copper Intermediate". COMMUNICATIONS 352 (23). doi:10.1002/adsc.201000456. http://www.chem.pku.edu.cn/zhangjl/papers/adsc.201000456.pdf. Retrieved 04/06/12. 
9. ^ Rattan, Gujadhur; D. Venkataraman and Jeremy T. Kintigh (2001). "Formation of aryl􏰈nitrogen bonds using a soluble copper(I) catalyst". TETRAHEDRON LETTERS. http://people.umass.edu/dv/pdf/tetlet1.pdf. 
10. ^ Gerard, Dijkstra; Wim H. Kruizinga, and Richard M. Kellogg (1987). "An Assessment of the Causes of the "Cesium Effect"". J . Org. Chem 52 (19): 4230. http://www.umich.edu/~chemh215/CHEM216/BasicTraining/Experiment2/cesium_effect.pdf. 
11. ^ Cesium

  Further reading

• Crich, David; Banerjee, Abhisek (2006), "Expedient Synthesis of syn-β-Hydroxy-α-amino acid derivatives: Phenylalanine, Tyrosine, Histidine and Tryptophan", J. Org. Chem. 71 (18): 7106–9, doi:10.1021/jo061159i, PMC 2621330, PMID 16930077 .

  External links

• Preparations from Organic Syntheses in which caesium carbonate appears
• Caesium carbonate factsheet from Chemetall GmbH
• Material Safety Data Sheet Cesium Carbonate, 99.5%
• Formation of aryl􏰈nitrogen bonds using a soluble copper(I) catalyst
• Cesium
• TOXICOLOGICAL PROFILE FOR CESIUM