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Neodymium(II) Bromide
Neodymium(II) bromide is an inorganic compound of neodymium and bromide. Preparation Neodymium(II) bromide can be obtained via the reduction of neodymium(III) bromide with neodymium in a vacuum at 800 to 900 °C.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. 1081. : Properties Neodymium(II) bromide is a dark green solid. The compound is extremely hygroscopic and can only be stored and handled under carefully dried inert gas or under a high vacuum. In air or on contact with water, it converts to hydrates by absorbing moisture, but these are unstable and more or less rapidly transform into oxybromides with evolution of hydrogen. The compound has the same crystal structure as lead(II) chloride Lead(II) chloride (PbCl2) is an inorganic compound which is a white solid under ambient conditions. It is poorly soluble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium(II) Fluoride
Neodymium(II) fluoride is an inorganic compound with the chemical formula NdF2. It can be obtained by shock compression of neodymium(III) fluoride and neodymium at 1000 °C and above 200 kbar. It can also be obtained by reacting in a eutectic system of neodymium and lithium fluoride Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid that transitions to white with decreasing crystal size. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. ...-neodymium(III) fluoride at 1100 °C. References External reading * {{Lanthanide halides Neodymium(II) compounds Fluorides Lanthanide halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium(II) Compounds
Neodymium is a chemical element; it has Symbol (chemistry), symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth element, rare-earth metals. It is a hard (physics), hard, slightly malleable, silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly producing pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states. It is generally regarded as having one of the most complex emission spectrum, spectra of the elements. Neodymium was discovered in 1885 by the Austrian chemist Carl Auer von Welsbach, who also discovered praseodymium. Neodymium is present in significant quantities in the minerals monazite and bastnäsite. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. Neodymium is fairly common—about as common as cobalt, nickel, or copper—and is Abundance of elements in Eart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead(II) Chloride
Lead(II) chloride (PbCl2) is an inorganic compound which is a white solid under ambient conditions. It is poorly soluble in water. Lead(II) chloride is one of the most important lead-based reagents. It also occurs naturally in the form of the mineral cotunnite. Structure and properties In solid PbCl2, each lead ion is coordinated by nine chloride ions in a tricapped triangular prism formation — six lie at the vertices of a triangular prism and three lie beyond the centers of each rectangular prism face. The 9 chloride ions are not equidistant from the central lead atom, 7 lie at 280–309 pm and 2 at 370 pm. PbCl2 forms white orthorhombic needles. In the gas phase, PbCl2 molecules have a bent structure with the Cl–Pb–Cl angle being 98° and each Pb–-Cl bond distance being 2.44 Å. Such PbCl2 is emitted from internal combustion engines that use ethylene chloride-tetraethyllead additives for antiknock purposes. PbCl2 is sparingly soluble in water, solu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in a material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of principal axes/edges, of the unit cell and angles between them are lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of a crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the chemical formula, formula , called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas (dihydrogen) and in molecular forms, such as in water and organic compounds. The most common isotope of hydrogen (H) consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 understood. Chemical nature Inorganic chemistry Hydrates are not inorganic salts "containing water molecules combined in a definite ratio as an integral part of the crystal" that are either bound to a metal center or that have crystallized with the metal complex. Such hydrates are also said to contain '' water of crystallization'' or ''water of hydration''. If the water is heavy water in which the constituent hydrogen is the isotope deuterium, then the term ''deuterate'' may be used in place of ''hydrate''. A colorful example is cobalt(II) chloride, which turns from blue to red upon hydration, and can therefore be used as a water indicator. The notation "''hydrated compound''⋅''n''", where ''n'' is the number of water molecules per form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopic
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, 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 dissolve in the water they absorb, forming an aqueous solution. Hygroscopy is essential for many plant and animal species' attainment of hydration, nutrition, reproduction and/or seed dispersal. Biological evolution created hygroscopic solutions for water harvesting, filament tensile strength, ... [...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 Technische Hochschule 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 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 * Phosphorus hydrides * Polycyclic organophosphanes * Mono- and polycyclic compounds of arsenic Selected publications Awards * Alfred Stork Memorial Prize in 1986 * Member of the Academy of Sciences Leopoldina starting in 1982 * Member of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Brauer
Georg Karl Brauer (11 April 1908 in Bochum – 26 February 2001 in Freiburg im Breisgau Freiburg im Breisgau or simply Freiburg is the List of cities in Baden-Württemberg by population, fourth-largest city of the German state of Baden-Württemberg after Stuttgart, Mannheim and Karlsruhe. Its built-up area has a population of abou ...) 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium(III) Bromide
Neodymium(III) bromide is an inorganic salt of bromine and neodymium the formula NdBr3. The anhydrous compound is an off-white to pale green solid at room temperature, with an orthorhombic PuBr3-type crystal structure. The material is hygroscopicDavid R. Lide (Hrsg.): ''CRC Handbook of Chemistry and Physics.'' 90. Auflage. (Internet-Version: 2010), CRC Press/Taylor and Francis, Boca Raton, FL, ''Properties of the Elements and Inorganic Compounds,'' S. 4-77. and forms a hexahydrate in water (NdBr3· 6H2O), similar to the related neodymium(III) chloride. Preparation The direct reaction of neodymium with bromine can create neodymium(III) bromide: :2Nd + 3Br2 → 2NdBr3 In the presence of carbon, neodymium(III) oxide reacts with carbon tetrabromide to produce neodymium(III) bromide. Structure Neodymium(III) bromide adopts the plutonium(III) bromide crystal structure. The neodymium ions are 8-coordinate and adopt a bicapped trigonal prismatic geometry. The neodymium–bromine b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium(II) Chloride
Neodymium(II) chloride or neodymium dichloride is a chemical compound of neodymium and chlorine with the formula NdCl2. Preparation Neodymium(II) chloride can be prepared by reducing neodymium(III) chloride with lithium metal/naphthalene or lithium chloride in THF. Reduction of neodymium(III) chloride with neodymium metal at temperatures above 650 °C also yields neodymium(II) chloride: :2 NdCl3 + Nd → 3 NdCl2 Structure Neodymium(II) chloride adopts the PbCl2 (cotunnite) structure. Each Nd2+ ion is coordinated by nine Cl− ions in a tricapped trigonal prismatic In chemistry, the tricapped trigonal prismatic molecular geometry describes the shape of compounds where nine atoms, groups of atoms, or ligand In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a ... arrangement. Seven of the Nd-Cl distances are in the range 2.95-3.14 Å while two are longer at 3.45 Å. References Chlorides Neodymium(II) compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
