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Ball-and-stick model of [UO2]2+
Ball-and-stick model of [UO2]2+
The uranyl ion, showing the U-O bond order of 3
The uranyl ion, showing the U-O bond order of 3
Diagram of a uranyl ion. The formation of two short U-O bonds in the uranyl ion prevents the closer approach of a third oxygen atom.
Diagram of a uranyl ion. Ball-and-stick models and Space-filling models (also known as Calotte models) are 3D or spatial Molecular models which serve to display the structure The formation of two short U-O bonds in the uranyl ion prevents the closer approach of a third oxygen atom. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the [1]

The uranyl ion is the dipositive cation [UO2]2+, which forms salts with acids. 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 this ion, uranium is in its +6 oxidation state. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. The other common oxidation state of uranium is uranium(IV), called uranous. Uranous is the Chemical term for the reduced tetrapositive Cation of Uranium that exhibits the valence U4+ The uranyl ion is the most common species encountered in the aqueous chemistry of uranium. Solid uranyl compounds are often colored red, yellow, orange or green. Like all uranium compounds, uranyl compounds are toxic. The toxicity of soluble uranyl salts is higher due to their faster incorporation into tissues.

Contents

Examples

Examples of uranyl compounds include:

Minerals

Such minerals occur in oxidised portions of uranium ore deposits. Uranium trioxide (UO3, also called Uranyl oxide, uranium(VI oxide, and uranic oxide, is the hexavalent Oxide of Uranyl acetate (UO2(CH3COO2·2H2O is a yellow free-flowing crystalline solid of yellow rhombic Crystals with a slight acetic odor Ammonium uranyl carbonate (UO2CO3·2(NH42CO3 is known in the Uranium processing industry as AUC and is also Uranium carbonate, UO2(CO3 is a Carbonate of Uranium that forms the backbone of several uranyl mineral species such as Andersonite Uranyl chloride, UO2Cl2 is an unstable bright yellow coloured chemical compound of Uranium. Uranyl hydroxide is a Hydroxide of Uranium with the chemical formula UO2(OH2 in the monomeric form and (UO22(OH2 Uranyl nitrate ( U[[oxygen O]]2( N[[oxygen O]]32 is a Water Soluble yellow Uranium salt Uranyl sulfate (UO2SO4 a Sulfate of Uranium presents as an odorless lemon-yellow sand-like solid in its pure crystalline form Uranyl zinc acetate (ZnUO2(CH3COO4is a compound of Uranium. Uranyl zinc acetate is used as a laboratory reagent in the determination of Common uranyl minerals include tyuyamunite (Ca(UO2)2V2O8·8H2O), autunite (Ca(UO2)2(PO4)2·8-12H2O), torbernite (Cu(UO2)2 (PO4)·8-12H2O) and uranophane (H3O)2Ca (UO2)2(SiO4)·3H2O) (Hutchinson and Blackwell, 1984). Carnotite is a Potassium Uranium Vanadate Mineral with Chemical formula: K 2( U[[oxygen O]]22( Autunite (hydrated calcium uranyl phosphate with formula Ca(UO22(PO42·10-12H2O is a yellow - greenish Fluorescent Torbernite, whose name derives from the Swedish chemist Torbern Bergman (1735-1784 is a Radioactive, green Phosphate Mineral, found in Uranophane Ca ( U[[oxygen O]]22( SiO sub>3O H)2·5 H2O is a rare calcium uranium Uranyl minerals, which contain uranium(VI) can help show the genesis of uranium deposits and the water-rock interactions that occur in uranium-rich mineral seams.

Chemistry

Uranium chemistry has traditionally revolved around the aqueous chemistry of the uranyl ion, and related molecular species. One important use of this chemistry is for preparation of uranium dioxide ceramic pellets that are used as the fuel in light water nuclear reactors. Uranium dioxide (2 an Oxide of Uranium, also known as urania or uranic oxide is a black radioactive crystalline powder See also Nuclear power "LWR" redirects here See also LWR (disambiguation A light water reactor or LWR is Often the fuel materials start to break down chemically before the uranium is completely spent, and this too is an active area of investigation, as many of the corrosion products are of the uranyl group.

Uses

Partially soluble uranyl salts such as uranyl acetate are used for microscopy stains. Uranyl acetate (UO2(CH3COO2·2H2O is a yellow free-flowing crystalline solid of yellow rhombic Crystals with a slight acetic odor These stains are used for electron and electromagnetic microscopy studies of DNA. [2]

Structure

The geometry of the uranyl ion has been the subject of much debate. The close approach of two oxygen atoms to uranium, with each linear O-U-O bond from 1. 7 to 1. 9 Å, prevents the close approach of a third or more. d-p and f-p bonding have been suggested to explain the short U-O bonds. [1]

Health and environmental issues

Uranyl nitrate is an oxidizing and highly toxic compound and should not be ingested; it causes severe renal insufficiency and acute tubular necrosis and is a lymphocyte mitogen. Ingestion is the consumption of a substance by an Organism. In Animals it normally is accomplished by taking in the substance through the Mouth into the Renal failure or kidney Acute tubular necrosis or ( ATN) is a medical condition involving the death of tubular cells that form the Tubule that transports Urine to the Ureters A lymphocyte is a type of White blood cell in the Vertebrate Immune system. A mitogen is a Chemical substance, usually some form of a Protein, that encourages a cell to commence Cell division, triggering Mitosis.

Target organs include the kidneys, liver, lungs and brain. The kidneys are complicated organs that have numerous biological roles The liver is a vital organ in the human body and is present in Vertebrates and some other animals lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain Uranyl ion accumulation in tissues including gonocytes[3] produces congenital disorders, and in white blood cells causes immune system damage. A congenital disorder is a disease or disorder that is present at birth [4] Uranyl compounds are also neurotoxins. A neurotoxin is a Toxin that acts specifically on nerve cells ( Neurons, usually by interacting with Membrane proteins such as Ion channels

Combustion of uranium

Aerial oxidation of any uranium compound eventually results in the formation of a uranyl compound. [1] Uranyl ion contamination has been found on and around depleted uranium targets. Depleted uranium (DU is Uranium primarily composed of the Isotope Uranium-238 (U-238 [5]

References

  1. ^ a b c Cotton, S (1991). Lanthanides and Actinides. New York: Oxford University Press, 128.  
  2. ^ Zobel, R. and Beer, M. (1961) "ELECTRON STAINS : I. Chemical Studies on the Interaction of DNA with Uranyl Salts" J. Biophys. and Biochem. Cytol. , vol. 10, pp. 335-346
  3. ^ Arfsten DP, Still KR, Ritchie GD (2001). "A review of the effects of uranium and depleted uranium exposure on reproduction and fetal development". Toxicology and Industrial Health 17: 180–191. doi:10.1191/0748233701th111oa. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  4. ^ Schröder H, Heimers A, Frentzel-Beyme R, Schott A, Hoffman W (2003). "Chromosome Aberration Analysis in Peripheral Lymphocytes of Gulf War and Balkans War Veterans". Radiation Protection Dosimetry 103: 211–219.  
  5. ^ Salbu B, Janssens K, Linda OC, Proost K, Gijsels L, Danesic PR (2004). "Oxidation states of uranium in depleted uranium particles from Kuwait". Journal of Environmental Radioactivity 78: 125–135. doi:10.1016/j.jenvrad.2004.04.001. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

Dictionary

uranyl

-noun

  1. (chemistry) The divalent radical UO22+, conveniently regarded as a residue of many uranium compounds.
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