|
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. :Nd + 2 NdBr3 -> 3 NdBr2 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 type. References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium(II) Fluoride
Neodymium is a chemical element with the 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, 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. It 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 Earth's crust, widely dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "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 pressure by around 20%. But hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium Compounds
Neodymium compounds are compounds formed by the lanthanide metal neodymium (Nd). In these compounds, neodymium generally exhibits the +3 oxidation state, such as NdCl3, Nd2(SO4)3 and Nd(CH3COO)3. Compounds with neodymium in the +2 oxidation state are also known, such as NdCl2 and NdI2. Some neodymium compounds have colors that vary based upon the type of lighting.Burke M.W. (1996) Lighting II: Sources. In: Image Acquisition. Springer, Dordrecht. File:Neodymium tl1.jpg, Neodymium compounds in fluorescent tube light—from left to right, the sulfate, nitrate, and chloride File:Neodymium fluorescent1.jpg, Neodymium compounds in compact fluorescent lamp light File:Neodymium daylight1.jpg, Neodymium compounds in normal daylight Halides Neodymium can form four trihalides of the form NdX3. It reacts vigorously with all the stable halogens: : violet substance: mauve substance: violet substance: green substance The dihalides NdCl2 and NdBr2 are dark green solids,Georg ... [...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. File:Cotunnite-3D-balls.png, Ball-and-stick model of part of the crystal structure of cotunnite File:Cotunnite-3D-ionic.png, Space-filling model File:Cotunnite-Pb-coordination-geometry-3D-balls.png, Coordination geometry of Pb2+ File:Cotunnite-Cl-coordination-geometry-3D-balls.png, Coordination geometry of Cl− File:Cot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystal, crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of Three-dimensional space (mathematics), three-dimensional space in matter. The smallest group of particles in the 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 (geometry), translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of the principal axes, or edges, of the unit cell and the angles between them are the lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of the crystal are described by the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
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, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...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 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 formula un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopic
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] |
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 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 the Göttingen Acade ... [...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 Eduard Zintl (21 January 1898 – 17 January 1941) was a German chemist. He gained prominence for research on intermetallic compounds. Family background After his family moved from Weiden and Bayreuth to Munich and after he had finished school ... 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 metal ... [...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 Tetrabromomethane, CBr4, also known as carbon tetrabromide, is a carbon bromide. Both names are acceptable under IUPAC nomenclature. Physical properties Tetrabromomethane has two polymorphs: crystalline II or β below 46.9 ... [...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 naphthalene, lithium metal/naphthalene or lithium chloride in Tetrahydrofuran, 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 lead(II) chloride, PbCl2 (cotunnite) structure. Each Nd2+ ion is coordinated by nine Cl− ions in a Tricapped trigonal prismatic molecular geometry, tricapped trigonal prismatic 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 compounds Lanthanide halides {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
sulfat.JPG "Click for more on -> Neodymium(II) Fluoride")
_chloride.jpg "Click for more on -> Hydrate")
