Uranyl nitrate

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Uranyl nitrate
Uranylnitrate crystals.jpg
UranylNitrate.svg
Uranyl-nitrate-dihydrate-from-xtal-3D-bs-17.png
Names
IUPAC name
(T-4)-bis(nitrato-κO)dioxouranium
Other names
Uranium nitrate, Yellow salt
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.229 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • anhydrous:233-266-3
PubChem CID
RTECS number
  • hexahydrate:YR3850000
UNII
  • anhydrous:InChI=1S/2NO3.2O.U/c2*2-1(3)4;;;/q2*-1;;; Yes check.svgY
    Key: QWDZADMNIUIMTC-UHFFFAOYSA-N Yes check.svgY
  • dihydrate:InChI=1S/2NO3.2H2O.2O.U/c2*2-1(3)4;;;;;/h;;2*1H2;;;/q2*-1;;;;;+2
    Key: SUFYIOKRRLBZBE-UHFFFAOYSA-N
  • hexahydrate:InChI=1S/2HNO3.6H2O.2O.U/c2*2-1(3)4;;;;;;;;;/h2*(H,2,3,4);6*1H2;;;
    Key: WRIBVRZWDPGVQH-UHFFFAOYSA-N
  • anhydrous:[N+](=O)([O-])[O-].O=[U+2]=O.[O-][N+](=O)[O-]
  • dihydrate:[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].O.O.O=[U+2]=O
  • hexahydrate:[N+](=O)(O)[O-].[N+](=O)(O)[O-].O.O.O.O.O.O.O=[U]=O
Properties
UO2(NO3)2
Molar mass 394.04 g/mol
Appearanceyellow-green solid
hygroscopic
Density 3.5 g/cm3 (dihydrate) [1]
Melting point 60.2 °C (140.4 °F; 333.3 K)
Boiling point 118 °C (244 °F; 391 K) (decomposition)
g/100g H2O: 98 (0°C), 122 (20°C), 474 (100°C)<
Solubility in tributyl phosphate soluble
Hazards
GHS labelling:
GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
4
0
0
OX
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
12 mg/kg (dog, oral)
238 (cat, oral) [2]
Safety data sheet (SDS) External MSDS
Related compounds
Other anions
Uranyl chloride
Uranyl sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Uranyl nitrate is a water-soluble yellow uranium salt with the formula UO2(NO3)2·n H2O. The hexa-, tri-, and dihydrates are known. [3] The compound is mainly of interest because it is an intermediate in the preparation of nuclear fuels. In the nuclear industry, it is commonly referred to as yellow salt.

Contents

Uranyl nitrate can be prepared by reaction of uranium salts with nitric acid. It is soluble in water, ethanol, and acetone. As determined by neutron diffraction, the uranyl center is characteristically linear with short U=O distances. In the equatorial plane of the complex are six U-O bonds to bidentate nitrate and two water ligands. At 245 pm, these U-O bonds are much longer than the U=O bonds of the uranyl center. [1]

Uses

Processing of nuclear fuels

Uranyl nitrate is important for nuclear reprocessing. It is the compound of uranium that results from dissolving the decladded spent nuclear fuel rods or yellowcake in nitric acid, for further separation and preparation of uranium hexafluoride for isotope separation for preparing of enriched uranium. A special feature of uranyl nitrate is its solubility in tributyl phosphate (), which allows uranium to be extracted from the nitric acid solution. Its high solubility is attributed to the formation of the lipophilic adduct UO2(NO3)2(OP(OBu)3)2.

Archaic photography

During the first half of the 19th century, many photosensitive metal salts had been identified as candidates for photographic processes, among them uranyl nitrate. The prints thus produced were called uranium prints or uranotypes. The first uranium printing processes were invented by Scotsman J. Charles Burnett between 1855 and 1857, and used this compound as the sensitive salt. Burnett authored a 1858 article comparing "Printing by the Salts of the Uranic and Ferric Oxides" The process employs the ability of the uranyl ion to pick up two electrons and reduce to the lower oxidation state of uranium(IV) under ultraviolet light. Uranotypes can vary from print to print from a more neutral, brown russet to strong Bartolozzi red, with a very long tone grade. Surviving prints are slightly radioactive, a property which serves as a means of non-destructively identifying them. Several other more elaborate photographic processes employing the compound appeared and vanished during the second half of the 19th century with names like Wothlytype, Mercuro-Uranotype and the Auro-Uranium process. Uranium papers were manufactured commercially at least until the end of the 19th century, vanishing due to the superior sensitivity and practical advantages of silver halides. From the 1930s through the 1950s Kodak Books described a uranium toner (Kodak T-9) using uranium nitrate hexahydrate.

Stain for microscopy

Along with uranyl acetate it is used as a negative stain for viruses in electron microscopy; in tissue samples it stabilizes nucleic acids and cell membranes.

As a reagent

Uranyl nitrates are common starting materials for the synthesis of other uranyl compounds because the nitrate ligand is easily replaced by other anions. It reacts with oxalate to give uranyl oxalate. Treatment with hydrochloric acid gives uranyl chloride. [4]

Health and environmental issues

Uranyl nitrate is an oxidizing and highly toxic compound. When ingested, it causes severe chronic kidney disease and acute tubular necrosis and is a lymphocyte mitogen. Target organs include the kidneys, liver, lungs and brain. It also represents a severe fire and explosion risk when heated or subjected to shock in contact with oxidizable substances.

Related Research Articles

The actinide or actinoid series encompasses at least the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through nobelium. The actinide series derives its name from the first element in the series, actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide.

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

Lead(II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2. It commonly occurs as a colourless crystal or white powder and, unlike most other lead(II) salts, is soluble in water.

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

Uranium hexafluoride, sometimes called hex, is an inorganic compound with the formula UF6. Uranium hexafluoride is a volatile and toxic white solid that reacts with water, releasing corrosive hydrofluoric acid. The compound reacts mildly with aluminium, forming a thin surface layer of AlF3 that resists any further reaction from the compound. UF6 is used in the process of enriching uranium, which produces fuel for nuclear reactors and nuclear weapons.

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

Magnesium nitrate refers to inorganic compounds with the formula Mg(NO3)2(H2O)x, where x = 6, 2, and 0. All are white solids. The anhydrous material is hygroscopic, quickly forming the hexahydrate upon standing in air. All of the salts are very soluble in both water and ethanol.

<span class="mw-page-title-main">PUREX</span> Spent fuel reprocessing process for plutonium and uranium recovery

PUREX is a chemical method used to purify fuel for nuclear reactors or nuclear weapons. PUREX is the de facto standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium from used nuclear fuel. It is based on liquid–liquid extraction ion-exchange.

The uranyl ion is an oxycation of uranium in the oxidation state +6, with the chemical formula UO2+
2
. It has a linear structure with short U–O bonds, indicative of the presence of multiple bonds between uranium and oxygen. Four or more ligands may be bound to the uranyl ion in an equatorial plane around the uranium atom. The uranyl ion forms many complexes, particularly with ligands that have oxygen donor atoms. Complexes of the uranyl ion are important in the extraction of uranium from its ores and in nuclear fuel reprocessing.

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

Uranium trioxide (UO3), also called uranyl oxide, uranium(VI) oxide, and uranic oxide, is the hexavalent oxide of uranium. The solid may be obtained by heating uranyl nitrate to 400 °C. Its most commonly encountered polymorph, γ-UO3, is a yellow-orange powder.

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

Aluminium nitrate is a white, water-soluble salt of aluminium and nitric acid, most commonly existing as the crystalline hydrate, aluminium nitrate nonahydrate, Al(NO3)3·9H2O.

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

Uranyl acetate is the acetate salt of uranium oxide, a toxic yellow-green powder useful in certain laboratory tests. Structurally, it is a coordination polymer with formula UO2(CH3CO2)2(H2O)·H2O.

Uranyl sulfate describes a family of inorganic compounds with the formula UO2SO4(H2O)n. These salts consist of sulfate, the uranyl ion, and water. They are lemon-yellow solids. Uranyl sulfates are intermediates in some extraction methods used for uranium ores. These compounds can also take the form of an anhydrous salt.

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

Uranyl peroxide or uranium peroxide hydrate (UO4·nH2O) is a pale-yellow, soluble peroxide of uranium. It is found to be present at one stage of the enriched uranium fuel cycle and in yellowcake prepared via the in situ leaching and resin ion exchange system. This compound, also expressed as UO3·(H2O2)·(H2O), is very similar to uranium trioxide hydrate UO3·nH2O. The dissolution behaviour of both compounds are very sensitive to the hydration state (n can vary between 0 and 4). One main characteristic of uranium peroxide is that it consists of small needles with an average AMAD of about 1.1 μm.

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

Uranyl chloride refers to inorganic compounds with the formula UO2Cl2(H2O)n where n = 0, 1, or 3. These are yellow-colored salts.

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

Uranium tetrachloride is an inorganic compound, a salt of uranium and chlorine, with the formula UCl4. It is a hygroscopic olive-green solid. It was used in the electromagnetic isotope separation (EMIS) process of uranium enrichment. It is one of the main starting materials for organouranium chemistry.

Uranium compounds are compounds formed by the element uranium (U). Although uranium is a radioactive actinide, its compounds are well studied due to its long half-life and its applications. It usually forms in the +4 and +6 oxidation states, although it can also form in other oxidation states.

The plutonyl ion is an oxycation of plutonium in the oxidation state +6, with the chemical formula PuO2+
2
. It is isostructural with the uranyl ion, compared to which it has a slightly shorter M–O bond. It is easily reduced to plutonium(III). The plutonyl ion forms many complexes, particularly with ligands that have oxygen donor atoms. Plutonyl salts are important in nuclear fuel reprocessing.

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

Cerium nitrate refers to a family of nitrates of cerium in the +3 or +4 oxidation state. Often these compounds contain water, hydroxide, or hydronium ions in addition to cerium and nitrate. Double nitrates of cerium also exist.

<span class="mw-page-title-main">Actinide chemistry</span> Branch of nuclear chemistry

Actinide chemistry is one of the main branches of nuclear chemistry that investigates the processes and molecular systems of the actinides. The actinides derive their name from the group 3 element actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide. All but one of the actinides are f-block elements, corresponding to the filling of the 5f electron shell; lawrencium, a d-block element, is also generally considered an actinide. In comparison with the lanthanides, also mostly f-block elements, the actinides show much more variable valence. The actinide series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.

<span class="mw-page-title-main">Thorium(IV) nitrate</span> Chemical compound

Thorium(IV) nitrate is a chemical compound, a salt of thorium and nitric acid with the formula Th(NO3)4. A white solid in its anhydrous form, it can form tetra- and pentahydrates. As a salt of thorium it is weakly radioactive.

Rhodium(III) nitrate is a inorganic compound, a salt of rhodium and nitric acid with the formula Rh(NO3)3. This anhydrous complex has been the subject of theoretical analysis but has not been isolated. However, a dihydrate and an aqueous solution are known with similar stoichiometry; they contain various hexacoordinated rhodium(III) aqua and nitrate complexes. A number of other rhodium nitrates have been characterized by X-ray crystallography: Rb4[trans-[Rh(H2O)2(NO3)4][Rh(NO3)6] and Cs2[-[Rh(NO3)5]. Rhodium nitrates are of interest because nuclear wastes, which contain rhodium, are recycled by dissolution in nitric acid.

Radium compounds are compounds containing the element radium (Ra). Due to radium's radioactivity, not many compounds have been well characterized. Solid radium compounds are white as radium ions provide no specific coloring, but they gradually turn yellow and then dark over time due to self-radiolysis from radium's alpha decay. Insoluble radium compounds coprecipitate with all barium, most strontium, and most lead compounds.

References

  1. 1 2 Mueller, Melvin Henry; Dalley, N. Kent; Simonsen, Stanley H. (1971). "Neutron Diffraction Study of Uranyl Nitrate Dihydrate". Inorganic Chemistry. 10 (2): 323–328. doi:10.1021/ic50096a021.
  2. "Uranium (soluble compounds, as U)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. Peehs, Martin; Walter, Thomas; Walter, Sabine; Zemek, Martin (2007). "Uranium, Uranium Alloys, and Uranium Compounds". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a27_281.pub2. ISBN   978-3527306732.
  4. F. Hein, S. Herzog (1963). "Uranyl Chloride". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2. NY, NY: Academic Press. p. 1439.