Cadmium fluoride

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Cadmium fluoride
Fluorite-unit-cell-3D-ionic.png
Names
IUPAC name
Cadmium fluoride
Other names
Cadmium(II) fluoride, Cadmium difluoride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.293 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 232-222-0
PubChem CID
UNII
  • InChI=1S/Cd.2FH/h;2*1H/q+2;;/p-2 Yes check.svgY
    Key: LVEULQCPJDDSLD-UHFFFAOYSA-L Yes check.svgY
  • InChI=1/Cd.2FH/h;2*1H/q+2;;/p-2
    Key: LVEULQCPJDDSLD-NUQVWONBAG
  • F[Cd]F
Properties
CdF2
Molar mass 150.41 g/mol
Appearancegrey or white-grey crystals
Density 6.33 g/cm3, solid
Melting point 1,110 °C (2,030 °F; 1,380 K)
Boiling point 1,748 °C (3,178 °F; 2,021 K)
4.35 g/100 mL
0.00644 [1]
Solubility soluble in acid
insoluble in ethanol alcohol and liquid ammonia
-40.6·10−6 cm3/mol
Structure
Fluorite (cubic), cF12
Fm3m, No. 225
Thermochemistry
-167.39 ± 0.23 kcal. mole-1 at 298.15 (K, C?)
-155.4 ± 0.3 kcal. mole-1 at 298.15 (K, C?)
Hazards
GHS labelling:
GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H301, H330, H340, H350, H360, H372, H410
P201, P202, P260, P264, P270, P271, P273, P281, P284, P301+P310, P304+P340, P308+P313, P310, P314, P320, P321, P330, P391, P403+P233, P405, P501
NIOSH (US health exposure limits):
PEL (Permissible)
[1910.1027] TWA 0.005 mg/m3 (as Cd) [2]
REL (Recommended)
Ca [2]
IDLH (Immediate danger)
Ca [9 mg/m3 (as Cd)] [2]
Related compounds
Other anions
Cadmium chloride,
Cadmium bromide
Cadmium iodide
Other cations
Zinc fluoride,
Mercury(II) fluoride,
Copper(II) fluoride,
Silver(II) fluoride,
Calcium fluoride,
Magnesium fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Cadmium fluoride (CdF2) is a mostly water-insoluble source of cadmium used in oxygen-sensitive applications, such as the production of metallic alloys. In extremely low concentrations (ppm), this and other fluoride compounds are used in limited medical treatment protocols. Fluoride compounds also have significant uses in synthetic organic chemistry. [3] The standard enthalpy has been found to be -167.39 kcal. mole−1 and the Gibbs energy of formation has been found to be -155.4 kcal. mole−1, and the heat of sublimation was determined to be 76 kcal. mole−1. [4] [5]

Contents

Preparation

Cadmium fluoride is prepared by the reaction of gaseous fluorine or hydrogen fluoride with cadmium metal or its salts, such as the chloride, oxide, or sulfate.

It may also be obtained by dissolving cadmium carbonate in 40% hydrofluoric acid solution, evaporating the solution and drying in a vacuum at 150 °C.

Another method of preparing it is to mix cadmium chloride and ammonium fluoride solutions, followed by crystallization. The insoluble cadmium fluoride is filtered from solution. [6]

Cadmium fluoride has also been prepared by reacting fluorine with cadmium sulfide. This reaction happens very quickly and forms nearly pure fluoride at much lower temperatures than other reactions used. [7]

Uses

Electronic conductor

CdF2 can be transformed into an electronic conductor when doped with certain rare earth elements or yttrium and treated with cadmium vapor under high temperature conditions. This process creates blue crystals with varying absorption coefficients depending on the concentrations of the dopant. A proposed mechanism explains that the conductivity of these crystals can be explained by a reaction of Cd atoms with Interstitial F ions. This creates more CdF2 molecules and releases electrons which are weakly bonded to trivalent dopant ions resulting in n-type conductivity and a hydrogenic donor level. [8]

Safety

Cadmium fluoride, like all cadmium compounds, is toxic and should be used with care.

Cadmium fluoride can cause potential health issues if it is not handled properly. It can cause irritation to the skin and the eyes, so gloves and protective eyewear are advised. The MSDS, or Material Safety Data Sheet, also includes warnings for ingestion and inhalation. Under acidic conditions, at high temperatures, and in moist environments, hydrogen fluoride and cadmium vapors may be released into the air. Inhalation may cause irritation of the respiratory system as well as congestion, fluorosis, and even pulmonary edema in extreme cases. Cadmium fluoride also has the same potential hazards caused by cadmium and fluoride. [9]

Related Research Articles

<span class="mw-page-title-main">Hydrofluoric acid</span> Solution of hydrogen fluoride in water

Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to etch glass and silicon wafers.

Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF2. It is a white solid that is practically insoluble in water. It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities.

<span class="mw-page-title-main">Cadmium sulfide</span> Chemical compound

Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow solid. It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores sphalerite and wurtzite, which are the major economic sources of cadmium. As a compound that is easy to isolate and purify, it is the principal source of cadmium for all commercial applications. Its vivid yellow color led to its adoption as a pigment for the yellow paint "cadmium yellow" in the 18th century.

<span class="mw-page-title-main">Oxygen difluoride</span> Chemical compound

Oxygen difluoride is a chemical compound with the formula OF2. As predicted by VSEPR theory, the molecule adopts a "bent" molecular geometry. It is strong oxidizer and has attracted attention in rocketry for this reason. With a boiling point of -144.75 °C, OF2 is the most volatile (isolable) triatomic compound. The compound is one of many known oxygen fluorides.

<span class="mw-page-title-main">Potassium fluoride</span> Ionic compound (KF)

Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide salt and occurs naturally as the rare mineral carobbiite. Solutions of KF will etch glass due to the formation of soluble fluorosilicates, although HF is more effective.

Iodine pentafluoride is an interhalogen compound with chemical formula IF5. It is one of the fluorides of iodine. It is a colorless liquid, although impure samples appear yellow. It is used as a fluorination reagent and even a solvent in specialized syntheses.

Nitryl fluoride, NO2F, is a colourless gas and strong oxidizing agent, which is used as a fluorinating agent and has been proposed as an oxidiser in rocket propellants (though never flown).

<span class="mw-page-title-main">Iron(II) fluoride</span> Chemical compound

Iron(II) fluoride or ferrous fluoride is an inorganic compound with the molecular formula FeF2. It forms a tetrahydrate FeF2·4H2O that is often referred to by the same names. The anhydrous and hydrated forms are white crystalline solids.

<span class="mw-page-title-main">Cobalt(II) fluoride</span> Chemical compound

Cobalt(II) fluoride is a chemical compound with the formula (CoF2). It is a pink crystalline solid compound which is antiferromagnetic at low temperatures (TN=37.7 K) The formula is given for both the red tetragonal crystal, (CoF2), and the tetrahydrate red orthogonal crystal, (CoF2·4H2O). CoF2 is used in oxygen-sensitive fields, namely metal production. In low concentrations, it has public health uses. CoF2 is sparingly soluble in water. The compound can be dissolved in warm mineral acid, and will decompose in boiling water. Yet the hydrate is water-soluble, especially the di-hydrate CoF2·2H2O and tri-hydrate CoF2·3H2O forms of the compound. The hydrate will also decompose with heat.

<span class="mw-page-title-main">Iron(III) fluoride</span> Chemical compound

Iron(III) fluoride, also known as ferric fluoride, are inorganic compounds with the formula FeF3(H2O)x where x = 0 or 3. They are mainly of interest by researchers, unlike the related iron(III) chlorides. Anhydrous iron(III) fluoride is white, whereas the hydrated forms are light pink.

<span class="mw-page-title-main">Copper(II) fluoride</span> Chemical compound

Copper(II) fluoride is an inorganic compound with the chemical formula CuF2. The anhydrous form is a white, ionic, crystalline, hygroscopic solid with a distorted rutile-type crystal structure, similar to other fluorides of chemical formulae MF2 (where M is a metal). The dihydrate, CuF2·2H2O, is blue in colour.

<span class="mw-page-title-main">Hydrogen fluoride</span> Chemical compound

Hydrogen fluoride (fluorane) is an inorganic compound with chemical formula HF. It is a very poisonous, colorless gas or liquid that dissolves in water to yield an aqueous solution termed hydrofluoric acid. It is the principal industrial source of fluorine, often in the form of hydrofluoric acid, and is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers, e.g. polytetrafluoroethylene (PTFE). HF is also widely used in the petrochemical industry as a component of superacids. Due to strong and extensive hydrogen bonding, it boils at near room temperature, much higher than other hydrogen halides.

<span class="mw-page-title-main">Xenon difluoride</span> Chemical compound

Xenon difluoride is a powerful fluorinating agent with the chemical formula XeF
2
, and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with water vapor, but is otherwise stable in storage. Xenon difluoride is a dense, colourless crystalline solid.

<span class="mw-page-title-main">Aluminium fluoride</span> Chemical compound

Aluminium fluoride refers to inorganic compounds with the formula AlF3·xH2O. They are all colorless solids. Anhydrous AlF3 is used in the production of aluminium metal. Several occur as minerals.

<span class="mw-page-title-main">Cadmium nitrate</span> Chemical compound

Cadmium nitrate describes any of the related members of a family of inorganic compounds with the general formula , the most commonly encountered form being the tetrahydrate. The anhydrous form is volatile, but the others are colourless crystalline solids that are deliquescent, tending to absorb enough moisture from the air to form an aqueous solution. Like other cadmium compounds, cadmium nitrate is known to be carcinogenic.

Cadmium hydride is an inorganic compound with the chemical formula (CdH
2
)
n
. It is a solid, known only as a thermally unstable, insoluble white powder.

<span class="mw-page-title-main">Cadmium tetrafluoroborate</span> Chemical compound

Cadmium tetrafluoroborate is an ionic, chemical compound with the formula Cd(BF4)2. It is a crystalline solid, which is colorless and odorless. Cadmium tetrafluoroborate is most frequently used in the industrial production of high-strength steels, its purpose being to prevent hydrogen absorption, a source of post-production cracking of the metal, in the treated steels. Another application of the chemistry of cadmium tetrafluoroborate is fine tuning of the size of cadmium telluride nanomaterials.

Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding. Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds. For many elements the highest known oxidation state can be achieved in a fluoride. For some elements this is achieved exclusively in a fluoride, for others exclusively in an oxide; and for still others the highest oxidation states of oxides and fluorides are always equal.

<span class="mw-page-title-main">Platinum tetrafluoride</span> Chemical compound

Platinum tetrafluoride is the inorganic compound with the chemical formula PtF
4
. In the solid state, the compound features platinum(IV) in octahedral coordination geometry.

<span class="mw-page-title-main">Hexafluoroarsenate</span> Chemical compound

The hexafluoroarsenate anion is a chemical species with formula AsF−6. Hexafluoroarsenate is relatively inert, being the conjugate base of the notional superacid hexafluoroarsenic acid.

References

  1. John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–188. ISBN   978-1138561632.
  2. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0087". National Institute for Occupational Safety and Health (NIOSH).
  3. "Cadmium Fluoride" . Retrieved 2009-06-06.
  4. Rudzitis, Edgars; Feder, Harold; Hubbard, Ward (November 1963). "Fluorine Bomb Calorimetry. VII. The Heat of Formation of Cadmium Difluoride". Journal of Physical Chemistry. 67 (11): 2388–2390. doi:10.1021/j100805a031.
  5. Besenbruch, G.; Kana'an, A. S.; Margrave, J. L. (March 3, 1965). "Knudson and Langmuir Measurements of the Sublimation Pressure of Cadmium (II) Fluoride". Journal of Physical Chemistry. 69 (9): 3174–3176. doi:10.1021/j100893a505.
  6. Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN   0-07-049439-8
  7. Haendler, Helmut; Bernard, Walter (November 1951). "The Reaction of Fluorine with Cadmium and Some of its Binary Compounds. The Crystal Structure, Density and Melting Points of Cadmium Fluoride". Journal of the American Chemical Society. 73. doi:10.1021/ja01155a064.
  8. Weller, Paul (June 1, 1965). "Electrical and Optical Properties of Rare Earth Doped Cadmium Fluoride Single Crystals". Inorganic Chemistry. 4 (11): 1545–1551. doi:10.1021/ic50033a004.
  9. "Cadmium Fluoride [CdF2]". MSDS Solutions Center. Advance Research Chemicals Inc. / A.R.C. 2011-04-01. Retrieved 2014-12-12.[ permanent dead link ]