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Gadolinium(III) Bromide
Gadolinium(III) bromide is a crystalline compound of gadolinium atoms and three bromine atoms. This salt is hygroscopic. Preparation Gadolinium(III) bromide can be obtained by the reaction between gadolinium and hydrobromic acid:Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: ''Handbuch der Präparativen Anorganischen Chemie.'' 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1077. :\mathrm The anhydrous form can be obtained by heating the hydrate with ammonium bromide Ammonium bromide, NH4Br, is the ammonium salt of hydrobromic acid. The chemical crystallizes in colorless prisms, possessing a saline taste; it sublimes on heating and is easily soluble in water. On exposure to air it gradually assumes a yellow c .... References {{Lanthanide halides Bromides Gadolinium compounds Lanthanide halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gadolinium(III) Fluoride
Gadolinium(III) fluoride is an inorganic compound with a chemical formula GdF3. Preparation Gadolinium(III) fluoride can be prepared by heating gadolinium oxide and ammonium bifluoride. The reaction involves two steps: : Gd2O3 + 6 NH4HF2 → 2 NH4GdF4 + 4 NH4F + 3 H2O : NH4GdF4 → GdF3 + NH3 + HF Alternatively, reacting gadolinium chloride with hydrofluoric acid and adding hot water produces GdF3·xH2O (x＝0.53). Anhydrous gadolinium(III) fluoride can then be produced by heating the hydrate with ammonium bifluoride; without the bifluoride, GdOF is formed instead. : GdCl3 + 3 HF + x H2O → GdF3·xH2O + 3 HCl Properties Gadolinium(III) fluoride is a white solid that is insoluble in water. It has an orthorhombic crystal structure with the space group Pnma (space group no. 62). Uses Gadolinium(III) fluoride is used to produce fluoride glass Fluoride glass is a class of non-oxide optical glasses composed of fluorides of various metals. They can contain heavy metals suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gadolinium(III) Chloride
Gadolinium(III) chloride, also known as gadolinium trichloride, is GdCl3. It is a colorless, hygroscopic, water-soluble solid. The hexahydrate GdCl3∙6H2O is commonly encountered and is sometimes also called gadolinium trichloride. Gd3+ species are of special interest because the ion has the maximum number of unpaired spins possible, at least for known elements. With seven valence electrons and seven available f-orbitals, all seven electrons are unpaired and symmetrically arranged around the metal. The high magnetism and high symmetry combine to make Gd3+ a useful component in NMR spectroscopy and MRI. Preparation GdCl3 is usually prepared by the " ammonium chloride" route, which involves the initial synthesis of (NH4)2 dCl5 This material can be prepared from the common starting materials at reaction temperatures of 230 °C from gadolinium oxide: ::10 NH4Cl + Gd2O3 → 2 (NH4)2 dCl5 + 6 NH3 + 3 H2O from hydrated gadolinium chloride: ::4 NH4Cl + 2 GdCl3∙6H2O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gadolinium
Gadolinium is a chemical element with the symbol Gd and atomic number 64. Gadolinium is a silvery-white metal when oxidation is removed. It is only slightly malleable and is a ductile rare-earth element. Gadolinium reacts with atmospheric oxygen or moisture slowly to form a black coating. Gadolinium below its Curie point of is ferromagnetic, with an attraction to a magnetic field higher than that of nickel. Above this temperature it is the most paramagnetic element. It is found in nature only in an oxidized form. When separated, it usually has impurities of the other rare-earths because of their similar chemical properties. Gadolinium was discovered in 1880 by Jean Charles de Marignac, who detected its oxide by using spectroscopy. It is named after the mineral gadolinite, one of the minerals in which gadolinium is found, itself named for the Finnish chemist Johan Gadolin. Pure gadolinium was first isolated by the chemist Paul-Émile Lecoq de Boisbaudran around 1886. Gadolini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromine
Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek (bromos) meaning "stench", referring to its sharp and pungent smell. Elemental bromine is very reactive and thus does not occur as a native element in nature but it occurs in colourless soluble crystalline mineral halide salts, analogous to table salt. In fact, bromine and all the halogens are so reactive that they form bonds in pairs—never in single atoms. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br) has caused its accumulation in the oceans. Commer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopy
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g., changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment. ''Deliquescent'' materials are sufficiently hygroscopic that they absorb so much water that they become liquid and form an aqueous solution. Etymology and pronunciation The word ''hygroscopy'' () uses combining forms of '' hygro-'' and '' -scopy''. Unlike any other ''-scopy'' word, it no longer refers to a viewing or imaging mode. It did begin that way, with the word ''hygroscope'' referring in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrobromic Acid
Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide (HBr) in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at and contains 47.6% HBr by mass, which is 8.77 mol/L. Hydrobromic acid has a p''K''a of −9, making it a stronger acid than hydrochloric acid, but not as strong as hydroiodic acid. Hydrobromic acid is one of the strongest mineral acids known. Uses Hydrobromic acid is mainly used for the production of inorganic bromides, especially the bromides of zinc, calcium, and sodium. It is a useful reagent for generating organobromine compounds. Certain ethers are cleaved with HBr. It also catalyzes alkylation reactions and the extraction of certain ores. Industrially significant organic compounds prepared from hydrobromic acid include allyl bromide, tetrabromobis(phenol), and bromoacetic acid. HBr almost uniquely participates in anti-Markovnikov hydrohalogenation of alkenes. The resulting 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Brauer
Georg Karl Brauer (born 11. April 1908 in Bochum, died 26. February 2001 in Freiburg im Breisgau) was a German chemist. Life Brauer was the son of the chemist Eberhard Brauer and Elisabeth Brauer, a daughter of Wilhelm Ostwald. From 1926 to 1932, Brauer studied in Leipzig and Freiburg. He received his doctorate under supervision of Eduard Zintl in Freiburg in 1933. In 1941, he received is habilitation at the TH Darmstadt. In 1946, he became an extraordinary professor in Freiburg. From 1959 to 1976, he was a full professor. Starting in 1976, he was a emeritus professor. Research Brauer's research included the chemistry and crystal chemistry of intermetallic compounds and alloys. He investigated binary systems of transition metals, in particular of oxides, nitrides, carbides, and hydrides of niobium, tantalum, and vanadium. His research also focused on oxides of rare-earth metals. Many new compounds and several new structure types (Li3N, Li3Bi, Al3Zr, ThSi2, NbO) were discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marianne Baudler
Marianne Baudler (27 April 1921 – 5 March 2003) was a German chemist. She is known for her research on phosphorus. Life Marianne Baudler was born in Stettin. She started studying Chemistry at the TH Dresden in April 1940 and finished her studies with a Diplom in 1943. From 1943 to 1946, she worked on her dissertation in the group of Franz Fehér Franz may refer to: People * Franz (given name) * Franz (surname) Places * Franz (crater), a lunar crater * Franz, Ontario, a railway junction and unorganized town in Canada * Franz Lake, in the state of Washington, United States – see ... at the University of Göttingen. Starting in 1949, Baudler performed research at the University of Cologne. In 1952, she finished her habilitation. In 1963 she became extraordinary professor at the University of Cologne. In 1968, the full professorship followed. From 1986 on, she was an emeritus professor. Research Her research focused on: * Small-ring phosphorus compounds * Phosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Bromide
Ammonium bromide, NH4Br, is the ammonium salt of hydrobromic acid. The chemical crystallizes in colorless prisms, possessing a saline taste; it sublimes on heating and is easily soluble in water. On exposure to air it gradually assumes a yellow color because of the oxidation of traces of bromide (Br−) to bromine (Br2). Preparation Ammonium bromide can be prepared by the direct action of hydrogen bromide on ammonia. : NH3 + HBr → NH4Br It can also be prepared by the reaction of ammonia with iron(II) bromide or iron(III) bromide, which may be obtained by passing aqueous bromine solution over iron filings. : 2 NH3 + FeBr2 + 2 H2O → 2 NH4Br + Fe(OH)2 Reactions Ammonium bromide is a weak acid with a pKa of ~5 in water. It is an acid salt because the ammonium ion hydrolyzes slightly in water. Ammonium Bromide is strong electrolyte when put in water: :NH4Br(s) → NH4+(aq) + Br−(aq) Ammonium bromide decomposes to ammonia and hydrogen bromide when heated at elevated tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromides
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation and rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gadolinium Compounds
Gadolinium is a chemical element with the symbol Gd and atomic number 64. Gadolinium is a silvery-white metal when oxidation is removed. It is only slightly malleable and is a ductile rare-earth element. Gadolinium reacts with atmospheric oxygen or moisture slowly to form a black coating. Gadolinium below its Curie point of is ferromagnetic, with an attraction to a magnetic field higher than that of nickel. Above this temperature it is the most paramagnetic element. It is found in nature only in an oxidized form. When separated, it usually has impurities of the other rare-earths because of their similar chemical properties. Gadolinium was discovered in 1880 by Jean Charles de Marignac, who detected its oxide by using spectroscopy. It is named after the mineral gadolinite, one of the minerals in which gadolinium is found, itself named for the Finnish chemist Johan Gadolin. Pure gadolinium was first isolated by the chemist Paul-Émile Lecoq de Boisbaudran around 1886. Gadolinium p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
