User:Simish/Caesium carbonate

Cesium Carbonate (Cs2CO3) is a white crystalline solid compound. Cesium 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 synthesis various compounds. Cesium carbonate is insoluble in most other organic solvents such as toluene, p-xylene, and chlorobenzene.

Cs2CO3.png Cesium Carbonate molecular structrue



For energy conversion
There is a huge growing desire in cesium and its compounds for energy conversion devices such as magneto-hydrodynamic generators, thermionic emitters, and fuel cells. Highly 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. 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. 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. 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 cesium 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. 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. Placing a Cs2CO3 layer in between the cathode and the light-releasing polymer improvers the efficiency of the white light emission emitting diode.

Synthesis
Cesium carbonate can be prepared by thermal decomposition of cesium oxalate. Upon heating cesium oxalate is converted to cesium carbonate and carbon monoxide is released. Heat + Cs2C2O4 -> Cs2CO3 + CO

It can also be synthesized by reacting Cesium hydroxide with carbon dioxide. 2CsOH + CO2 -> Cs2CO3 + H2O

Chemical Reaction
Cesium 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. In the presence of gold sodium chloride (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. The process of selective oxidation of alcohols to carbonyls had been quite difficult due to the nucleophilic character of the carbonyl intermediate. 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. Cesium carbonate can also be used in Suzuki, Heck, and Sonogashira synthesis reactions. Cesium carbonate produces carbonylation of alcohols and carbamination of amines more efficiently than some of the mechanisms that have been introduced in the past. Cesium carbonate can be used for sensitive synthesis when a balanced strong base is needed.

Cesium compound Salts
Weak cesium salts are important to the synthesis of important compounds such as phenol, sulfonamide, thiol, carboxylic acids and 1,3-dicarbonyl compounds. Cesium carbonate produces carbon dioxide whenever it comes in contact with stomach acids. When carbonate salts reacts with hydrochloric acids carbon dioxide and water are produced. Cs2CO3 + 2HCl -> CO2 + H2O

Stability
Stability: stable under standard pressure and temperature.

Material safety
Causes eye, skin and digestive tract irritations.

Cesium
Many of the cesium carbonates properties comes form the cesium element. Cesium 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. Cesium 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.

External link

 * Material Safety Data Sheet Cesium Carbonate, 99.5%
 * Formation of aryl􏰈nitrogen bonds using a soluble copper(I) catalyst
 * Cesium
 * TOXICOLOGICAL PROFILE FOR CESIUM