Uranyl acetate

Uranyl acetate
Uranyl acetate

Hydrated crystal structure
Names
IUPAC name
Uranium bis((acetato)-O)dioxo-dihydrate
Other names
Uranyl ethanoate; Uranyl acetate dihydrate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.007.971 Edit this at Wikidata
EC Number
  • (anhydrous): 208-767-5
UNII
  • (anhydrous): InChI=1S/2C2H4O2.2O.U/c2*1-2(3)4;;;/h2*1H3,(H,3,4);;;
    Key: IXSMFXMQHOBORU-UHFFFAOYSA-N
  • (dihydrate): InChI=1S/2C2H4O2.2H2O.2O.U/c2*1-2(3)4;;;;;/h2*1H3,(H,3,4);2*1H2;;;/q;;;;;;+2/p-2
    Key: VVAHPLNXWRLLIG-UHFFFAOYSA-L
  • (anhydrous) ionic form (anhydrate): O=C(C)[O-].[O+]#[U]#[O+].O=C(C)[O-]
  • (dihydrate): CC(=O)[O-].CC(=O)[O-].O.O.O=[U+2]=O
  • coordination dimer (hydrate): O0[C-](C)O[U+6]01(=[O-2])(=[O-2])([OH2])O[C-](C)O[U+6]2(O[C-](C)O2)(=[O-2])(=[O-2])([OH2])O[C-](C)O1
  • coordination dimer (anhydrous): O0[C-](C)O[U+6]01(=[O-2])(=[O-2])O[C-](C)O[U+6]0(O[C-](C)O0)(=[O-2])(=[O-2])O[C-](C)O1
Properties
UO2(CH3COO)2 (anhydrous)
UO2(CH3COO)2·2H2O (dihydrate)
Molar mass 424.146 g/mol (dihydrate)
Appearance yellow-green crystals (dihydrate)
Density 2.89 g/cm3 (dihydrate)
Melting point decomposes at 80 °C (dihydrate)
7-8 g/100 ml
Solubility slightly soluble in ethanol
Hazards
GHS labelling:
GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
Danger
H300, H330, H373, H411
P260, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P314, P320, P321, P330, P391, P403+P233, P405, P501
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

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.

Structure

In the polymer, uranyl (UO22+) centers are bridged by acetate ligands. The remainder of each (heptacoordinate) coordination sphere is provided by an aquo ligand and a bidentate acetate ligand. One water of crystallization occupies the lattice.

Uses

Uranyl acetate is extensively used as a negative stain in electron microscopy. Most procedures in electron microscopy for biology require the use of uranyl acetate. Negative staining protocols typically treat the sample with 1% to 5% aqueous solution. Uranyl acetate staining is simple and quick to perform and one can examine the sample within a few minutes after staining. Some biological samples are not amenable to uranyl acetate staining and, in these cases, alternative staining techniques and or low-voltage electron microscopy technique may be more suitable.

1% and 2% uranyl acetate solutions are used as an indicator, and a titrant in stronger concentrations in analytical chemistry, as it forms an insoluble salt with sodium (the vast majority of sodium salts are water-soluble). Uranyl acetate solutions show evidence of being sensitive to light, especially UV, and will precipitate if exposed.

Uranyl acetate is also used in a standard test—American Association of State Highway and Transportation Officials (AASHTO) Designation T 299—for alkali-silica reactivity in aggregates (crushed stone or gravel) being considered for use in cement concrete.

Uranyl acetate dihydrate has been used as a starting reagent in experimental inorganic chemistry.

Related compounds

Uranyl carboxylates are known for diverse carboxylic acids (formate, butyrate, acrylate).

Safety

Uranyl acetate is both chemically toxic and mildly radioactive. Chronic-exposure effects may cumulate.[citation needed]

In general, uranium salts exhibit nephrotoxicity. Normal commercial stocks from depleted uranium have typical specific activity 0.37–0.51 microcuries per gram (14–19 kBq/g), too weak to harm from outside the body. However, uranyl acetate is very toxic if ingested, inhaled as dust, or absorbed through cut or abraded skin.[citation needed]

Microbiologists have developed a number of alternative stains: neodymium acetate, platinum blue, hafnium chloride, and oolong tea extracts.


This page was last updated at 2024-03-14 21:29 UTC. Update now. View original page.

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