| Caesium fluoride | |
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| IUPAC name | Caesium fluoride |
| Other names | Cesium fluoride |
| Identifiers | |
| CAS number | [13400-13-0] |
| RTECS number | FK9650000 |
| Properties | |
| Molecular formula | CsF |
| Molar mass | 151. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 904 g/mol |
| Appearance | white crystalline solid |
| Density | 4. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 115 g/cm³, solid |
| Melting point | 682 °C (955 K) |
| Boiling point | 1251 °C (1524 K) |
| Solubility in water | 367 g/100 ml (18 °C) |
| Structure | |
| Crystal structure | cubic |
| Coordination geometry | Octahedral |
| Dipole moment | 7. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. The cubic crystal system (or isometric) is a Crystal system where the Unit cell is in the shape of a Cube. The term coordination geometry is used in a number of related fields of chemistry and solid state chemistry/physics An octahedron (plural octahedra is a Polyhedron with eight faces In physics there are two kinds of dipoles ( Hellènic: di(s- = two- and pòla = pivot hinge An electric dipole is a 9 D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | toxic, forms HF with acid |
| R-phrases | 23/24/25, 34 |
| S-phrases | 26, 36/37, 39, 45 |
| Related compounds | |
| Other anions | caesium chloride caesium bromide caesium iodide |
| Other cations | sodium fluoride potassium fluoride rubidium fluoride |
| Related compounds | tetra-n-butylammonium fluoride |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references | |
Caesium fluoride (cesium fluoride in North America), is an ionic compound usually found as a hygroscopic white solid. The debye (symbol D) is a non- SI, CGS unit of electrical dipole moment. A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance Occupational safety and health is a cross-disciplinary area concerned with protecting the Safety, Health and welfare of people engaged in In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Cesium chloride is the Chemical compound with the formula Cs[[Chlorine Cl]] Caesium bromide, (CsBr is an ionic compound of Caesium and Bromine. Caesium iodide (CsI is an Ionic compound often used as the input Phosphor of an X-ray image intensifier tube found in Fluoroscopy equipment An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Sodium fluoride is the Chemical compound with the formula NaF Potassium fluoride is the Chemical compound with the formula KF Rubidium fluoride (RbF is the Fluoride salt of Rubidium. It is an Octahedral Crystal. Tetra- n -butylammonium fluoride or TBAF is a Quaternary ammonium salt with the chemical formula (CH3CH2CH2CH24N+F- In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly It is more soluble and more readily dissociated than sodium fluoride or potassium fluoride. Dissociation in Chemistry and Biochemistry is a general process in which ionic compounds ( complexes, Molecules, or Salts) separate Sodium fluoride is the Chemical compound with the formula NaF Potassium fluoride is the Chemical compound with the formula KF It is available in anhydrous form, and if water has been absorbed it is easy to dry by heating at 100 °C for two hours in vacuo. The Celsius Temperature scale was previously known as the centigrade scale. [1] It is therefore a useful, less hygroscopic alternative to tetra-n-butylammonium fluoride (TBAF) and TAS-fluoride (TASF) when anhydrous "naked" fluoride ion is needed. Hygroscopy is the ability of a substance to attract Water Molecules from the surrounding environment through either absorption or Adsorption Tetra- n -butylammonium fluoride or TBAF is a Quaternary ammonium salt with the chemical formula (CH3CH2CH2CH24N+F- The TASF reagent or tris(dimethylaminosulfonium difluorotrimethylsilicate is a Reagent in Organic chemistry with Structural formula +- Fluoride is the reduced form of Fluorine. Both organic and Inorganic compounds containing the element fluorine are considered fluorides An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Like all soluble fluorides, it is mildly basic. In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and Contact with acid should be avoided, as this forms highly toxic/corrosive hydrofluoric acid. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Hydrofluoric acid is a Solution of Hydrogen fluoride in Water.
Contents |
Chemical properties
Caesium fluoride reacts usually as a source of fluoride ion, F-. It therefore undergoes all of the usual reactions associated with soluble fluorides such as potassium fluoride, for example:[2]
2 CsF (aq) + CaCl2 (aq) → 2 CsCl (aq) + CaF2 (s)
Being highly dissociated it is quite reactive as a fluoride source under anhydrous conditions too, and it will react with electron-deficient aryl chlorides to form aryl fluorides (halex reaction). Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. Cesium chloride is the Chemical compound with the formula Cs[[Chlorine Cl]] Calcium fluoride (CaF2 is an insoluble Ionic compound of Calcium and Fluorine. A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. Due to the strength of the Si–F bond, fluoride ion is useful for desilylation reactions (removal of Si groups) in organic chemistry; caesium fluoride is an excellent source of anhydrous fluoride for such reactions (vida infra). Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation As with other soluble fluorides, CsF is moderately basic, because HF is a weak acid. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. The low nucleophilicity of fluoride means it can be a useful base in organic chemistry. In Chemistry, a nucleophile (literally nucleus lover as in nucleus and phile) is a Reagent that forms a Chemical bond to [2]
Crystal structure
Caesium fluoride has the inverse halite structure, because caesium ions are larger than fluoride ions; in the lithium, sodium, potassium, and rubidium halides, the cation is smaller than the anion. The caesium ions form a cubic closest packed array with fluoride ions in the octahedral holes. [2][3]
Preparation
Caesium fluoride may be prepared by the action of hydrofluoric acid on caesium hydroxide or caesium carbonate, followed by removal of water. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. Caesium hydroxide (CsOH is a Chemical compound consisting of an atom of Caesium and a Hydroxide group (also known as Hydroxyl)
Uses
Caesium fluoride is a useful base in organic chemistry, due the fact that fluoride ion is largely unreactive as a nucleophile. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge In Chemistry, a nucleophile (literally nucleus lover as in nucleus and phile) is a Reagent that forms a Chemical bond to It is reported that CsF gives higher yields in Knoevenagel condensation reactions than KF or NaF. The Knoevenagel condensation reaction is an Organic reaction named after Emil Knoevenagel. Potassium fluoride is the Chemical compound with the formula KF Sodium fluoride is the Chemical compound with the formula NaF [4]
Removal of silicon groups (desilylation) is a major application for CsF in the laboratory, as its anhydrous nature allows clean formation of water-sensitive intermediates. As a general term a substance is said to be anhydrous if it contains no Water. Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as Caesium fluoride in THF or DMF can attack a wide variety of organosilicon compounds to produce an organosilicon fluoride and a carbanion, which can then react with electrophiles,[3] for example:[4]
Desilylation is also useful for the removal of silyl protecting groups. "THF" redirects here For other uses see THF (disambiguation. Dimethylformamide is the Organic compound with the formula ( CH3)2NC(OH Organosilicon compounds are organic compounds containing Carbon Silicon bonds. A carbanion is an Anion in which Carbon has an unshared pair of Electrons and bears a negative charge usually with three substituents for a total of eight In Chemistry, an electrophile (literally electron-lover) is a Reagent attracted to Electrons that participates in a chemical reaction by accepting Silane is a Chemical compound with Chemical formula Si[[hydrogen H]]4 A protecting group or protective group is introduced into a molecule by chemical modification of a Functional group in order to obtain Chemoselectivity
Caesium fluoride is also a popular source of fluoride in organofluorine chemistry. Fluorocarbons are chemical compounds that contain Carbon - Fluorine bonds The relatively low reactivity and high polarity of the carbon-fluorine bond imparts For example, CsF reacts with hexafluoroacetone to form a caesium perfluoroalkoxide salt which is stable up to 60 °C, unlike the corresponding sodium or potassium salt. Hexafluoroacetone is a Chemical compound with the formula CF3-CO-CF3 Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 [5]
Single crystals of the salt are transparent into the deep infrared. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of For this reason it is often used as the windows of cells used for infrared spectroscopy. Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum.
Precautions
Like other soluble fluorides, CsF is moderately toxic. [6] Contact with acid should be avoided, as this forms highly toxic/corrosive hydrofluoric acid. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. Cesium ion (Cs+), or Cesium chloride, is generally not considered toxic. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge [7]
References
- ^ Friestad, G. K. ; Branchaud, B. P. in: Handbook of Reagents for Organic Synthesis: Acidic and Basic Reagents, (Reich, H. J. ; Rigby, J. H. eds. ), Wiley, New York, 1999. pp. 99-103.
- ^ a b c Greenwood, N. N. ; Earnshaw, A. Chemistry of the Elements, Pergamon Press, Oxford, UK, 1984.
- ^ a b Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
- ^ a b Fiorenza, M. ; Mordini, A. ; Papaleo, S. ; Pastorelli, S. ; Ricci, A. 1985. Tetrahedron Letters. 26, 787.
- ^ F. W. Evans, M. H. Litt, A. M. Weidler-Kubanek, F. P. Avonda "Reactions Catalyzed by Potassium Fluoride. 111. The Knoevenagel Reaction. " 1968. Journal of Organic Chemistry. 33, 1837-1839. Retrieved on September 7, 2007. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.
- ^ "MSDS Listing for cesium flouride. " www.hazard.com. MSDS Date: April 27, 1993. Events 1124 - David I becomes King of Scotland. 1296 - Battle of Dunbar: The Scots are defeated Year 1993 ( MCMXCIII) was a Common year starting on Friday (link will display full 1993 Gregorian calendar) Retrieved on September 7, 2007. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.
- ^ "MSDS Listing for cesium chloride. " www.jtbaker.com. MSDS Date: January 16, 2006. Events 27 BC - The title Augustus is bestowed upon Gaius Julius Caesar Octavian by the Roman Senate. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Retrieved on September 7, 2007. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.
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