Europium(III) acetate is an inorganic salt of

europium Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanth ...

and

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...

with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

of Eu(CH₃COO)₃. In this compound, europium exhibits the +3

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...

. It can exist in the

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

form, sesqui

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

and tetrahydrate. Its hydrate molecule is a

dimer Dimer may refer to: * Dimer (chemistry), a chemical structure formed from two similar sub-units ** Protein dimer, a protein quaternary structure ** d-dimer * Dimer model, an item in statistical mechanics, based on ''domino tiling'' * Julius Dimer ( ...

Preparation

Europium acetate can be obtained by stirring reaction of

and

europium oxide Europium oxide is a compound from the two elements europium and oxygen. Europium oxide may refer to: * Europium(II) oxide (europium monoxide, EuO) a magnetic semiconductor. * Europium(III) oxide (europium sesquioxide, Eu2O3), the most common ...

under heating, and then diluting with water and crystallizing: : Eu₂O₃ + 6 CH₃COOH → 2 Eu(CH₃COO)₃ + 3 H₂O

Europium Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanth ...

can also directly participate in the reaction: : 2 Eu + 6 CH₃COOH → 2 Eu(CH₃COO)₃ + 3 H₂↑

Properties

Physical properties

The anhydrous europium acetate crystallizes monoclinically in the

space group In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it unchan ...

''C2/c'' (space group no. 15) with the lattice parameters ''a'' = 1126.0(3), ''b'' = 2900.5(6), ''c'' = 799.1( 2) pm and ''β'' = 132.03(2)° with four formula units per unit cell. The sesquihydrate crystallizes monoclinically in the space group Cc (No. 9) with the lattice parameters a = 1608.7(2), b = 1665.6(2), c = 839.1(1) pm and β = 115.75( 9)° with four

formula unit In chemistry, a formula unit is the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound. Exa ...

s per

unit cell In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessaril ...

. The

heat capacity Heat capacity or thermal capacity is a physical property of matter, defined as the amount of heat to be supplied to an object to produce a unit change in its temperature. The SI unit of heat capacity is joule per kelvin (J/K). Heat capacity i ...

at 280 K is 803±16 J/(mol∙K).

Chemical properties

Europium acetate can be dissolved in water, acidified with

, and the compound of divalent europium u(CH₃COO)₂(CH₃COOH)(H₂O)₂can be obtained by

electrochemical reduction Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outco ...

. Europium acetate can be crystallized in excess glacial acetic acid to give the salt u(H(CH₃COO)₂)₃H₂O).

Decomposition

Europium acetate can be decomposed by heating, and the hydrate first loses water to obtain anhydrous, and then passes through basic acetate EuOCH₃COO, basic carbonate Eu₂O₂CO₃, and finally obtains europium oxide.Ogawa M, Manabe K
Thermal Decomposition of Europium (III) Acetate Tetrahydrate
（酢酸ユウロピウム(III)4水和物の熱分解）. ''Journal of the Ceramic Society of Japan'', 1988, 96(1117): 890-893. The tetrahydrate of europium acetate decomposes in air over 6 stages to europium oxide. Stage 1 at 135 °C: :Eu(CH₃COO)₃·4H₂O → Eu(CH₃COO)₃·H₂O + 3H₂O Stage 2 at 170 °C: :Eu(CH₃COO)₃·3H₂O → Eu(CH₃COO)₃·0.5 H₂O + 0.5 H₂O Stage 3 at 210 °C: :Eu(CH₃COO)₃·0.5H₂O → Eu(CH₃COO)₃ + 0.5 H₂O Stage 4 at 310 °C: :Eu(CH₃COO)₃ → EuO(CH₃COO) + C₃H₆O + CO₂ Stage 5 at 390 °C: :2EuO(CH₃COO) → Eu₂O₂ O₃+ C₃H₆O Stage 6 at 670 °C: :Eu₂O₂ O₃→ Eu₂O₃ + CO₂

Notes

References

{{europium compounds Acetates Europium(III) compounds