Caesium carbonate

Caesium carbonate or cesium carbonate is a white crystalline solid compound. Caesium carbonate has a high solubility in polar solvents such as water, alcohol and DMF. Its solubility is higher in organic solvents compared to other carbonates like potassium and sodium carbonates, although it remains quite insoluble in other organic solvents such as toluene, p-xylene, and chlorobenzene. This compound is used in organic synthesis as a base. It also appears to have applications in energy conversion.

Caesium carbonate[1]
Cesiumcarbonaat
Caesium-carbonate-3D-Balls
Caesium carbonate
Names
IUPAC name
Caesium carbonate
Other names
Cesium carbonate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.007.812
EC Number 208-591-9
Properties
Cs2CO3
Molar mass 325.82 g/mol
Appearance white powder
Density 4.072 g/cm3
Melting point 610 °C (1,130 °F; 883 K) (decomposes)
2605 g/L (15 °C)
Solubility in ethanol 110 g/L
Solubility in dimethylformamide 119.6 g/L
Solubility in dimethyl sulfoxide 361.7 g/L
Solubility in sulfolane 394.2 g/L
Solubility in methylpyrrolidone 723.3 g/L
-103.6·10−6 cm3/mol
Hazards
Flash point Non-flammable
Related compounds
Other anions
Caesium bicarbonate
Other cations
Lithium carbonate
Sodium carbonate
Potassium carbonate
Rubidium carbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Preparation

Caesium carbonate can be prepared by thermal decomposition of caesium oxalate.[2] Upon heating, caesium oxalate is converted to caesium carbonate and carbon monoxide is released:

Cs2C2O4 → Cs2CO3 + CO

It can also be synthesized by reacting caesium hydroxide with carbon dioxide.[2]

2 CsOH + CO2 → Cs2CO3 + H2O

Chemical reactions

Caesium carbonate is very important for the N-alkylation of compounds such as sulfonamides, amines, β-lactams, indoles, heterocyclic compounds, N-substituted aromatic imides, phthalimides, and several similar other compounds.[3] Research on these compounds has focused on their synthesis and biological activity.[4] In the presence of sodium tetrachloroaurate (NaAuCl4), cesium 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.[5] The process of selective oxidation of alcohols to carbonyls had been quite difficult due to the nucleophilic character of the carbonyl intermediate.[4] In the past Cr(VI) and Mn(VII) reagents have been used to oxidize alcohols, however, these reagents are toxic and comparatively expensive. Cesium 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.[6] Caesium carbonate can be used for sensitive synthesis when a balanced strong base is needed.

For energy conversion

There is growing demand for cesium and its compounds for energy conversion devices such as magneto-hydrodynamic generators, thermionic emitters, and fuel cells.[2] Relatively effective polymer solar cells are built by thermal annealing of cesium carbonate. Cesium carbonate increases the energy effectiveness of the power conversion of solar cells and enhances the life times of the equipment.[7] The studies done on UPS and XPS reveal that the system will do less work due to the thermal annealing of the Cs2CO3 layer. Cesium 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.[8] 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.[9] 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.[7] Placing a Cs2CO3 layer in between the cathode and the light-emitting polymer improves the efficiency of the white OLED.

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 E. L. Simons; E. J. Cairns; L. D. Sangermano (1966). "Purification and preparation of some caesium compounds". Talanta. 13 (2): 199–204. doi:10.1016/0039-9140(66)80026-7. PMID 18959868.
  3. ^ 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.
  4. ^ 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 temperature". Chemical Communications. 5556 (55). doi:10.1039/b908964k.
  5. ^ Lie, Liand; Guodong Rao; Hao-Ling Sun; Jun-Long Zhang (2010). "Aerobic Oxidation of Primary Alcohols Catalyzed by Copper Salts and Catalytically Active m-Hydroxyl-Bridged Trinuclear Copper Intermediate" (PDF). Advances in Synthesis and Catlaysis. 352 (23). doi:10.1002/adsc.201000456. Archived from the original (reprint) on 2014-02-01. Retrieved 2012-04-27.
  6. ^ Rattan, Gujadhur; D. Venkataraman; Jeremy T. Kintigh (2001). "Formation of aryl–nitrogen bonds using a soluble copper(I) catalyst" (PDF). Tetrahedron Letters. doi:10.1016/s0040-4039(01)00888-7.
  7. ^ a b Jinsong, Huang; Zheng Xu; Yang Yang (2007). 2CO3.pdf "Low-Work-Function Surface Formed by Solution-Processed and Thermally Deposited Nanoscale Layers of Cesium Carbonate" (PDF). Advanced Functional Materials. 17 (19). doi:10.1002/adfm.200700051. Retrieved 2012-03-31.
  8. ^ Hua-Hstien, Liao; Li-Min Chen; Zheng Xu; Gang Li; Yang Yang (2008). "Highly efficient inverted polymer solar cell by low temperature annealing of Cs2CO3 interlayer" (PDF). Applied Physics Letters. 92 (17). doi:10.1063/1.2918983.
  9. ^ Jen-Chun, Wang; Wei-Tse Weng; Meng-Yen Tsai; Ming-Kun Lee; Sheng-Fu Horng; Tsong-Pyng Perng; Chi-Chung Kei; Chih-Chieh Yuc; Hsin-Fei Meng. "Highly efficient flexible inverted organic solar cells using atomic layer deposited ZnO as electron selective layer". Journal of Materials.

Further reading

External links

Caesium

Caesium (IUPAC spelling) or cesium (American spelling) is a chemical element with symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. The most reactive of all metals, it is pyrophoric and reacts with water even at −116 °C (−177 °F). It is the least electronegative element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite, while the radioisotopes, especially caesium-137, a fission product, are extracted from waste produced by nuclear reactors.

The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the newly developed method of flame spectroscopy. The first small-scale applications for caesium were as a "getter" in vacuum tubes and in photoelectric cells. In 1967, acting on Einstein's proof that the speed of light is the most constant dimension in the universe, the International System of Units used two specific wave counts from an emission spectrum of caesium-133 to co-define the second and the metre. Since then, caesium has been widely used in highly accurate atomic clocks.

Since the 1990s, the largest application of the element has been as caesium formate for drilling fluids, but it has a range of applications in the production of electricity, in electronics, and in chemistry. The radioactive isotope caesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology. Nonradioactive caesium compounds are only mildly toxic, but the pure metal's tendency to react explosively with water means that caesium is considered a hazardous material, and the radioisotopes present a significant health and ecological hazard in the environment.

Caesium acetate

Caesium acetate or cesium acetate is an ionic caesium compound with the molecular formula CH3CO2Cs. It is often used in organic synthesis especially in Perkin synthesis: the formation of unsaturated cinnamic-type acids by the condensation of aromatic aldehydes with fatty acids.It may be formed by the reaction of caesium hydroxide or caesium carbonate with acetic acid. Caesium acetate is occasionally used instead of caesium formate in petroleum drilling fluids.

Caesium bicarbonate

Caesium bicarbonate or cesium bicarbonate is a chemical compound with the chemical formula CsHCO3. It can be produced through the following reaction:

Cs2CO3 + CO2 + H2O → 2 CsHCO3The compound can be used for synthesizing caesium salts, but less common than caesium carbonate.

Caesium fluoride

Caesium fluoride or cesium fluoride is an inorganic compound usually encountered as a hygroscopic white solid. It is used in organic synthesis as a source of the fluoride anion.

Diethyl phenylmalonate

Diethyl phenylmalonate is an aromatic malonic ester used in the synthesis of moderate to long lasting barbiturates such as phenobarbital.

Glossary of chemical formulas

This is a list of common chemical compounds with chemical formulas and CAS numbers, indexed by formula. This complements alternative listing at inorganic compounds by element. There is no complete list of chemical compounds since by nature the list would be infinite.

Note: There are elements for which spellings may differ, such as aluminum/ aluminium, sulfur/ sulphur, and caesium/ cesium.

Julia olefination

The Julia olefination (also known as the Julia–Lythgoe olefination) is the chemical reaction used in organic chemistry of phenyl sulfones (1) with aldehydes (or ketones) to give alkenes (olefins)(3) after alcohol functionalization and reductive elimination using sodium amalgam[1][2] or SmI2.[3] The reaction is named after the French chemist Marc Julia.

The utility of this connective olefination reaction arises from its versatility, its wide functional group tolerance, and the mild reaction conditions under which the reaction proceeds.

All four steps can be carried out in a single reaction vessel, and use of R3X is optional. However, purification of the sulfone intermediate 2 leads to higher yield and purity. Most often R3 is acetyl or benzoyl, with acetic anhydride or benzoyl chloride used in the preparation of 2.

List of CAS numbers by chemical compound

This is a list of CAS numbers by chemical formulas and chemical compounds, indexed by formula. This complements alternative listings to be found at list of inorganic compounds, list of organic compounds and inorganic compounds by element.

List of inorganic compounds

Although most compounds are referred to by their IUPAC systematic names (following IUPAC nomenclature), "traditional" names have also been kept where they are in wide use or of significant historical interests.

Lithium carbonate

Lithium carbonate is an inorganic compound, the lithium salt of carbonate with the formula Li2CO3. This white salt is widely used in the processing of metal oxides.

For the treatment of bipolar disorder, it is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.

Oseltamivir total synthesis

Oseltamivir total synthesis concerns the total synthesis of the antiinfluenza drug oseltamivir marketed by Hoffmann-La Roche under the trade name Tamiflu. Its commercial production starts from the biomolecule shikimic acid harvested from Chinese star anise with a limited worldwide supply. Due to its limited supply, searches for alternative synthetic routes preferably not requiring shikimic acid are underway and to date several such routes have been published. Control of stereochemistry is important: the molecule has three stereocenters and the sought-after isomer is only 1 of 8 stereoisomers.

Potassium carbonate

Potassium carbonate is the inorganic compound with the formula K2CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass.

Rubidium carbonate

Rubidium carbonate, Rb2CO3, is a convenient compound of rubidium; it is stable, not particularly reactive, and readily soluble in water, and is the form in which rubidium is usually sold.

Seyferth–Gilbert homologation

The Seyferth–Gilbert homologation is a chemical reaction of an aryl ketone 1 (or aldehyde) with dimethyl (diazomethyl)phosphonate 2 and potassium tert-butoxide to give substituted alkynes 3. Dimethyl (diazomethyl)phosphonate 2 is often called the Seyferth–Gilbert reagent.

This reaction is called a homologation because the product has exactly one additional carbon more than the starting material.

Sodium carbonate

Sodium carbonate, Na2CO3, (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, water-soluble salts. All forms have a strongly alkaline taste and give moderately alkaline solutions in water. Historically it was extracted from the ashes of plants growing in sodium-rich soils. Because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process.

Thiol-yne reaction

The thiol-yne reaction (also known as alkyne hydrothiolation) is an organic reaction between a thiol and an alkyne. The reaction product is an alkenyl sulfide. The reaction was first reported in 1949 with thioacetic acid as reagent and rediscovered in 2009. It is used in click chemistry and in polymerization, especially with dendrimers.

This addition reaction is typically facilitated by a radical initiator or UV irradiation and proceeds through a sulfanyl radical species.With monoaddition a mixture of (E/Z)-alkenes form. The mode of addition is anti-Markovnikov. The radical intermediate can engage in secondary reactions such as cyclisation. With diaddition the 1,2-disulfide or the 1,1- dithioacetal forms. Reported catalysts for radical additions are triethylborane, indium(III) bromide and AIBN. The reaction is also reported to be catalysed by cationic rhodium and iridium complexes, by thorium and uranium complexes, by rhodium complexes, by caesium carbonate and by gold.

Diphenyl disulfide reacts with alkynes to a 1,2-bis(phenylthio)ethylene. Reported alkynes are ynamides. A photoredox thiol-yne reaction has been reported.

Caesium compounds

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