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Europium Compounds
Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod. Properties of europium compounds Chalcogenides Oxides Europium(II) oxide can be obtained by the reduction of europium(III) oxide with metallic europium at high temperatures. It has a rock-salt structure, is a deep red solid, and is ferromagnetic at 77 K. It has the potential to become a magnetic refrigeration material (ΔSmag=−143 mg/cm3 K，50 kOe).无机化学丛书. pp 200-203. 2. 氧族化合物; pp 215. 3. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminescence Of Europium Compounds
Luminescence is spontaneous emission of light by a substance not resulting from heat; or "cold light". It is thus a form of cold-body radiation. It can be caused by chemical reactions, electric potential energy, electrical energy, subatomic motions or piezoelectricity, stress on a crystal. This distinguishes luminescence from incandescence, which is light emitted by a substance as a result of heating. Historically, radioactive decay, radioactivity was thought of as a form of "radio-luminescence", although it is today considered to be separate since it involves more than electromagnetic radiation. The dials, hands, scales, and signs of aviation and navigational instruments and markings are often coated with luminescent materials in a process known as "luminising". Types The following are types of luminescence: *Chemiluminescence, the emission of light as a result of a chemical reaction **Bioluminescence, a result of biochemical reactions in a living organism **Electrochemilumines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(III) Fluoride
Europium(III) fluoride is an inorganic compound with a chemical formula EuF3. Production Europium(III) fluoride can produced by reacting europium(III) nitrate and ammonium fluoride: : Eu(NO3)3 + 3 NH4F → EuF3 + 3 NH4NO3 Europium(III) fluoride nanoparticles can be synthesized by microwave irradiation of europium(III) acetate in an ionic liquid that has tetrafluoroborate Tetrafluoroborate is the anion . This tetrahedral species is isoelectronic with tetrafluoroberyllate (), tetrafluoromethane (CF4), and tetrafluoroammonium () and is valence isoelectronic with many stable and important species including the perchl ... as the anion. References {{Lanthanide halides Europium(III) compounds Fluorides Lanthanide halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(II) Oxide
Europium(II) oxide (EuO) is a chemical compound which is one of the oxides of europium. In addition to europium(II) oxide, there is also europium(III) oxide and the mixed valence europium(II,III) oxide. Preparation Europium(II) oxide can be prepared by the Redox, reduction of europium(III) oxide with elemental europium at 800 °C and subsequent vacuum distillation at 1150 °C. :Eu2O3 + Eu → 3 EuO It is also possible to synthesize from the reaction of europium oxychloride and lithium hydride. :2 EuOCl + 2 LiH → 2 EuO + 2 LiCl + H2 In modern research, thin films can be manufactured by molecular beam epitaxy directly from europium atoms and oxygen molecules. These films have contamination of Eu3+ of less than 1%. Properties Europium(II) oxide is a violet compound as a bulk crystal and transparent blue in thin film form. It is unstable in humid atmosphere, slowly turning into the yellow europium(II) hydroxide hydrrate and then to white europium(III) hydroxide. EuO crys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexagonal
In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A '' regular hexagon'' has Schläfli symbol and can also be constructed as a truncated equilateral triangle, t, which alternates two types of edges. A regular hexagon is defined as a hexagon that is both equilateral and equiangular. It is bicentric, meaning that it is both cyclic (has a circumscribed circle) and tangential (has an inscribed circle). The common length of the sides equals the radius of the circumscribed circle or circumcircle, which equals \tfrac times the apothem (radius of the inscribed circle). All internal angles are 120 degrees. A regular hexagon has six rotational symmetries (''rotational symmetry of order six'') and six reflection symmetries (''six lines of symmetry''), making up the dihedral group D6. The longest diagonals of a regular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(III) Hydroxide
Europium(III) hydroxide is an inorganic compound with a chemical formula Eu(OH)3. Chemical properties Europium(III) hydroxide can be prepared by reacting metallic europium with water. It reacts with acids In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ... and produces europium(III) salts: : Eu(OH)3 + 3 H+ → Eu3+ + 3 H2O Europium(III) hydroxide decomposes to EuO(OH) at elevated temperature. Further decomposition produces Eu2O3. References {{hydroxides Europium(III) compounds Hydroxides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthorhombic
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (''a'' by ''b'') and height (''c''), such that ''a'', ''b'', and ''c'' are distinct. All three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal. Bravais lattices There are four orthorhombic Bravais lattices: primitive orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic. For the base-centered orthorhombic lattice, the primitive cell has the shape of a right rhombic prism;See , row oC, column Primitive, where the cell parameters are given as a1 = a2, α = β = 90° it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length a of the primit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(II) Hydroxide
Europium(II) hydroxide is an inorganic compound, with the chemical formula of Eu(OH)2. It can exist as the dihydrate Eu(OH)2·H2O. Preparation The monohydrate of europium(II) hydroxide can be obtained by the reaction of metal europium and 10 mol/L sodium hydroxide solution. There are some sources that use europium(III) chloride as a raw material, and prepare it by reacting the Jones reductor with sodium hydroxide solution. Properties Europium(II) hydroxide belongs to the orthorhombic crystal system, a=6.701 ± 0.002, b=6.197 ± 0.002, c=3.652 ± 0.001 A. It thermally decomposes to form europium(II) oxide (EuO); it is readily oxidized to europium(III) hydroxide Europium(III) hydroxide is an inorganic compound with a chemical formula Eu(OH)3. Chemical properties Europium(III) hydroxide can be prepared by reacting metallic europium with water. It reacts with acids In computer science, ACID ( atomicity, ... in air.无机化学丛书 第七卷 钪 稀土元素. 科学出版 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(II) Hydride
Europium hydride is the most common hydride of europium with a chemical formula EuH2. In this compound, europium atom is in the +2 oxidation state and the hydrogen atoms are -1. It is a ferromagnetic semiconductor. Production Europium hydride can be produced by directly reacting europium and hydrogen gas Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, a ...: : Eu + H2 → EuH2 Uses EuH2 can be used as a source of Eu2+ to create metal-organic frameworks that have the Eu2+ ion. References {{Hydrides by group Europium(II) compounds Metal hydrides Ferromagnetic materials ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bismuth(III) Iodide
Bismuth(III) iodide is the inorganic compound with the formula Bi I3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis. Bismuth(III) iodide adopts a distinctive crystal structure, with iodide centres occupying a hexagonally closest-packed lattice, and bismuth centres occupying either none or two-thirds of the octahedral holes (alternating by layer), therefore it is said to occupy one third of the total octahedral holes. Synthesis Bismuth(III) iodide forms upon heating an intimate mixture of iodine and bismuth powder: :2Bi + 3I2 → 2BiI3 BiI3 can also be made by the reaction of bismuth oxide with aqueous hydroiodic acid: :Bi2O3(s) + 6HI(aq) → 2BiI3(s) + 3H2O(l) Reactions Since bismuth(III) iodide is insoluble in water, an aqueous solution can be tested for the presence of Bi3+ ions by adding a source of iodide such as potassium iodide. A black precipitate of bismuth(III) iodide indica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemists. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handbook'' as an incentive for any purchase of a dozen aprons. Since then the ''Rubber Handbook'' has evolved into the CRC's flagship book, the '' CRC Handbook of Chemistry and Physics''. In 1964, Chemical Rubber decided to focus on its publishing ventures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Handbook Of Chemistry And Physics
The ''CRC Handbook of Chemistry and Physics'' is a comprehensive one-volume reference resource for science research. First published in 1914, it is currently () in its 103rd edition, published in 2022. It is sometimes nicknamed the "Rubber Bible" or the "Rubber Book", as CRC originally stood for "Chemical Rubber Company". As late as the 1962–1963 edition (3604 pages) the ''Handbook'' contained myriad information for every branch of science and engineering. Sections in that edition include: Mathematics, Properties and Physical Constants, Chemical Tables, Properties of Matter, Heat, Hygrometric and Barometric Tables, Sound, Quantities and Units, and Miscellaneous. Earlier editions included sections such as "Antidotes of Poisons", "Rules for Naming Organic Compounds", "Surface Tension of Fused Salts", "Percent Composition of Anti-Freeze Solutions", "Spark-gap Voltages", "Greek Alphabet", "Musical Scales", "Pigments and Dyes", "Comparison of Tons and Pounds", "Twist Drill and St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(III) Iodide
Europium(III) iodide is an inorganic compound containing europium and iodine with the chemical formula . Preparation Europium metal reacts directly with iodine to form europium(III) iodide: : Hydrated europium(III) iodide can be prepared dissolving europium(III) oxide or europium(III) carbonate in hydroiodic acid: : Europium powder reacts with iodine in THF to form a THF adduct of europium(III) iodide: : The adduct can be formulated more simply as . Structure Europium(III) iodide adopts the bismuth(III) iodide (BiI3) crystal structure type, with octahedral coordination of each Eu3+ ion by 6 iodide ions. Reactivity Europium(III) iodide is used as the starting material for two of the main ways of preparing europium(II) iodide: Reduction with hydrogen gas at 350 °C: : Thermal decomposition at 200 °C, a disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
