Chemistry:Uranyl acetate
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 Hydrated crystal structure
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| Names | |
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| IUPAC name
Uranium bis((acetato)-O)dioxo-dihydrate
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| Other names
Uranyl ethanoate; Uranyl acetate dihydrate
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| Identifiers | |
3D model (JSmol)
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PubChem CID
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| 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[1] |
| Hazards | |
| Safety data sheet | External MSDS |
| GHS pictograms |   
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| GHS Signal word | Danger |
| H300, H330, H373, H411 | |
| P260, P264, P270, P271, P273, P284, P301+310, P304+340, P310, P314, P320, P321, P330, P391, P403+233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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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.[2]
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 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:[6] neodymium acetate,[7][8] platinum blue,[9] hafnium chloride,[10] and oolong tea extracts.[11][12]
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.
- ↑ Yamaguchi K, Suzuki K, Tanaka K (2010) Examination of electron stains as a substitute for uranyl acetate for the ultrathin sections of bacterial cells. J Electron Microsc (Tokyo) 59:113–118
- ↑ Kuipers, Jeroen; Giepmans, Ben N. G. (1 April 2020). "Neodymium as an alternative contrast for uranium in electron microscopy" (in en). Histochemistry and Cell Biology 153 (4): 271–277. doi:10.1007/s00418-020-01846-0. ISSN 1432-119X. PMID 32008069.
- ↑ Hosogi N, Nishioka H, Nakakoshi M (2015) Evaluation of lanthanide salts as alternative stains to uranyl acetate. Microscopy (Oxf) 64:429–435
- ↑ Inaga S, Katsumoto T, Tanaka K, Kameie T, Nakane H, Naguro T (2007) Platinum blue as an alternative to uranyl acetate for staining in transmission electron microscopy. Arch Histol Cytol 70:43–49
- ↑ Ikeda K, Inoue K, Kanematsu S, Horiuchi Y, Park P (2011) Enhanced effects of nonisotopic hafnium chloride in methanol as a substitute for uranyl acetate in TEM contrast of ultrastructure of fungal and plant cells. Microsc Res Tech 74:825–830
- ↑ Sato S, Adachi A, Sasaki Y, Ghazizadeh M (2008) Oolong tea extract as a substitute for uranyl acetate in staining of ultrathin sections. J Microsc 229:17–20
- ↑ He X, Liu B (2017) Oolong tea extract as a substitute for uranyl acetate in staining of ultrathin sections based on examples of animal tissues for transmission electron microscopy. J Microsc 267:27–33
Acetyl halides and salts of the acetate ion
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| AcOH | He | ||||||||||||||||||
| LiOAc | Be(OAc)2 BeAcOH |
B(OAc)3 | AcOAc ROAc |
NH4OAc | AcOOH | FAc | Ne | ||||||||||||
| NaOAc | Mg(OAc)2 | Al(OAc)3 ALSOL Al(OAc)2OH Al2SO4(OAc)4 |
Si | P | S | ClAc | Ar | ||||||||||||
| KOAc | Ca(OAc)2 | Sc(OAc)3 | Ti(OAc)4 | VO(OAc)3 | Cr(OAc)2 Cr(OAc)3 |
Mn(OAc)2 Mn(OAc)3 |
Fe(OAc)2 Fe(OAc)3 |
Co(OAc)2, Co(OAc)3 |
Ni(OAc)2 | Cu(OAc)2 | Zn(OAc)2 | Ga(OAc)3 | Ge | As(OAc)3 | Se | BrAc | Kr | ||
| RbOAc | Sr(OAc)2 | Y(OAc)3 | Zr(OAc)4 | Nb | Mo(OAc)2 | Tc | Ru(OAc)2 Ru(OAc)3 Ru(OAc)4 |
Rh2(OAc)4 | Pd(OAc)2 | AgOAc | Cd(OAc)2 | In | Sn(OAc)2 Sn(OAc)4 |
Sb(OAc)3 | Te | IAc | Xe | ||
| CsOAc | Ba(OAc)2 | Hf | Ta | W | Re | Os | Ir | Pt(OAc)2 | Au | Hg2(OAc)2, Hg(OAc)2 |
TlOAc Tl(OAc)3 |
Pb(OAc)2 Pb(OAc)4 |
Bi(OAc)3 | Po | At | Rn | |||
| Fr | Ra | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og | |||
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| La(OAc)3 | Ce(OAc)x | Pr | Nd | Pm | Sm(OAc)3 | Eu(OAc)3 | Gd(OAc)3 | Tb | Dy(OAc)3 | Ho(OAc)3 | Er | Tm | Yb(OAc)3 | Lu(OAc)3 | |||||
| Ac | Th | Pa | UO2(OAc)2 | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | |||||
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