Uranyl acetate

Uranyl acetate
Names
	IUPAC name Uranium bis((acetato)-O)dioxo-dihydrate
	Other names Uranyl ethanoate; Uranyl acetate dihydrate
Identifiers
CAS Number	(anhydrous): 541-09-3 ; (dihydrate): 6159-44-0 ;
3D model (JSmol)	(anhydrous) ionic form (anhydrate): Interactive image; (dihydrate): Interactive image; coordination dimer (hydrate): Interactive image; coordination dimer (anhydrous): Interactive image;
ChemSpider	(anhydrous): 10468551; (dihydrate): 11567664;
ECHA InfoCard	100.007.971
EC Number	(anhydrous): 208-767-5;
PubChem CID	(anhydrous): 10915;
UNII	(anhydrous): 285PN2K1AO ; (dihydrate): KJF3TEU4G6 ;
CompTox Dashboard (EPA)	(anhydrous): DTXSID3060243 ;
	InChI (anhydrous): InChI=1S/2C2H4O2.2O.U/c21-2(3)4;;;/h21H3,(H,3,4);;; Key: IXSMFXMQHOBORU-UHFFFAOYSA-N; (dihydrate): InChI=1S/2C2H4O2.2H2O.2O.U/c21-2(3)4;;;;;/h21H3,(H,3,4);2*1H2;;;/q;;;;;;+2/p-2 Key: VVAHPLNXWRLLIG-UHFFFAOYSA-L;
	SMILES (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): [o+]0c(C)o[U-5]01(#[O+])(#[O+])([O+H2])[o+]c(C)o[U-5]0([o+]c(C)o0)(#[O+])(#[O+])([O+H2])[o+]c(C)o1; coordination dimer (anhydrous): [o+]0c(C)o[U-4]01(#[O+])(#[O+])[o+]c(C)o[U-4]0([o+]c(C)o0)(#[O+])(#[O+])[o+]c(C)o1;
Properties
Chemical formula	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)
Solubility in water	7-8 g/100 ml
Solubility	slightly soluble in ethanol
Hazards
Safety data sheet (SDS)	External MSDS
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H330, H373, H411
Precautionary statements	P260, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P314, P320, P321, P330, P391, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
	(what is ?)
	Infobox references

Uranyl acetate refers to the coordination polymer with the formula {[UO₂(CH₃CO₂)₂H₂O)]H₂O}_n. 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.^[2] It is a yellow-green solid.

Uses[]

Uranyl acetate is extensively used as a negative stain in electron microscopy.^[3] 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.^[4]

Related compounds[]

Uranyl carboxylates are known for diverse carboxylic acids (formate, butyrate, acrylate).^[5]

Safety[]

Uranyl acetate is both radioactive and toxic. Normal commercial stocks prepared from depleted uranium have a typical specific activity of 0.37–0.51 microcuries (14–19 kBq) per gram. This mild level of radioactivity is insufficient to be harmful while the material remains external to the body.

Uranyl acetate is very toxic if ingested, inhaled as dust or by skin contact if skin is cut or abraded. The toxicity is due to the combined effect of chemical toxicity and mild radioactivity and there is a danger of cumulative effects from long term exposure.

References[]

^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 3–566, ISBN 0-8493-0594-2
^ Howatson, J.; Grev, D.M.; Morosin, B. (1975). "Crystal and molecular structure of uranyl acetate dihydrate". Journal of Inorganic and Nuclear Chemistry. 37 (9): 1933–1935. doi:10.1016/0022-1902(75)80918-3.
^ "Negative Staining" University of Oxford
^ Sessler, Jonathan L.; Seidel, Daniel; Vivian, Anne E.; Lynch, Vincent; Scott, Brian L.; Keogh, D. Webster (2001). "Hexaphyrin(1.0.1.0.0.0): An Expanded Porphyrin Ligand for the Actinide Cations Uranyl (UO₂²⁺) and Neptunyl (NpO₂⁺)". Angewandte Chemie International Edition. 40 (3): 591–594. doi:10.1002/1521-3773(20010202)40:3<591::AID-ANIE591>3.0.CO;2-0.
^ Klepov, Vladislav V.; Vologzhanina, Anna V.; Alekseev, Evgeny V.; Pushkin, Denis V.; Serezhkina, Larisa B.; Sergeeva, Olga A.; Knyazev, Aleksandr V.; Serezhkin, Viktor N. (2016). "Structural diversity of uranyl acrylates". CrystEngComm. 18 (10): 1723–1731. doi:10.1039/C5CE01957E.

[hand-1] Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 3–566, ISBN 0-8493-0594-2

[2] Howatson, J.; Grev, D.M.; Morosin, B. (1975). "Crystal and molecular structure of uranyl acetate dihydrate". Journal of Inorganic and Nuclear Chemistry. 37 (9): 1933–1935. doi:10.1016/0022-1902(75)80918-3.

[NEGSTAIN-3] "Negative Staining" University of Oxford

[4] Sessler, Jonathan L.; Seidel, Daniel; Vivian, Anne E.; Lynch, Vincent; Scott, Brian L.; Keogh, D. Webster (2001). "Hexaphyrin(1.0.1.0.0.0): An Expanded Porphyrin Ligand for the Actinide Cations Uranyl (UO₂²⁺) and Neptunyl (NpO₂⁺)". Angewandte Chemie International Edition. 40 (3): 591–594. doi:10.1002/1521-3773(20010202)40:3<591::AID-ANIE591>3.0.CO;2-0.

[5] Klepov, Vladislav V.; Vologzhanina, Anna V.; Alekseev, Evgeny V.; Pushkin, Denis V.; Serezhkina, Larisa B.; Sergeeva, Olga A.; Knyazev, Aleksandr V.; Serezhkin, Viktor N. (2016). "Structural diversity of uranyl acrylates". CrystEngComm. 18 (10): 1723–1731. doi:10.1039/C5CE01957E.

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