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Vanadium Tribromide
Vanadium(III) bromide, also known as vanadium tribromide, describes the inorganic compounds with the formula VBr3 and its hydrates. The anhydrous material is a green-black solid. In terms of its structure, the compound is polymeric with octahedral vanadium(III) surrounded by six bromide ligands. Preparation VBr3 has been prepared by treatment of vanadium tetrachloride with hydrogen bromide: ::2 VCl4 + 8 HBr → 2 VBr3 + 8 HCl + Br2 The reaction proceeds via the unstable vanadium(IV) bromide (VBr4), which releases Br2 near room temperature. It is also possible to prepare vanadium(III) bromide by reacting bromine with vanadium or ferrovanadine: :: 2 V + 3 Br2 → 2 VBr3 ::2 VFe + 6 Br2 → 2 VBr3 + FeBr3 Properties Physical Vanadium(III) bromide is present in the form of black, leafy, very hygroscopic crystals with a sometimes greenish sheen. It is soluble in water with green color. Its crystal structure is isotypic to that of vanadium(III) chloride with space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium(III) Chloride
Vanadium(III) chloride describes the inorganic compound with the formula VCl3 and its hydrates. It forms a purple anhydrous form and a green hexahydrate Cl2(H2O)4l·2H2O. These hygroscopic salts are common precursors to other vanadium(III) complexes and is used as a mild reducing agent. Structure and electronic configuration VCl3 has the common layered BiI3 structure, a motif that features hexagonally closest-packed chloride framework with vanadium ions occupying the octahedral holes. VBr3 and VI3 adopt the same structure, but VF3 features a structure more closely related to ReO3. The V3+cation has a ''d''2 electronic configuration with two unpaired electrons, making the compound paramagnetic.Greenwood, N. N. and Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. p. 990 . VCl3 is a Mott insulator and undergoes an antiferromagnetic transition at low temperatures. Solid hexahydrate, Cl2(H2O)4l·2H2O, has a monoclinic crystal structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium(III) Bromide
Titanium(III) bromide is the inorganic compound with the formula TiBr3. It is a blue black paramagnetic solid with a reddish reflection. It has few applications, although it is a catalyst for the polymerization of alkenes. Production and structure TiBr3 can be produced by heating the tetrabromide in an atmosphere of hydrogen: :2TiBr4 + H2 → 2TiBr3 + 2HBr It can also be produced by comproportionation Comproportionation or symproportionation is a chemical reaction where two reactants containing the same element but with different oxidation numbers, form a compound having an intermediate oxidation number. It is the opposite of disproportionatio ... of titanium metal and titanium tetrabromide. :Ti + 3TiBr4 → 4TiBr3 Two polymorphs of TiBr3 are known, each exhibiting octahedral Ti centers.Troyanov, S. I.; Rybakov, V. B.; Ionov, V. M. "Preparation and crystal structure of titanium tetrabromide, titanium tribromide and titanium(2+) tetrabromoaluminate(1-)" Zhurnal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molybdenum(III) Bromide
Molybdenum(III) bromide is the inorganic compound with the formula MoBr3. It is a black solid that is insoluble in most solvents but dissolves in donor solvents such as pyridine. Preparation Molybdenum(III) bromide is produced by the reaction of elemental molybdenum and bromine at .F. Hein, S. Herzog "Molybdenum(III) Bromide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1407. :\mathrm It can also be prepared from the reduction of molybdenum(IV) bromide with molybdenum metal, hydrogen gas, or a hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain .... It has a structure consisting of infinite chains of face-sharing octahedra with alternatingly short and long Mo-Mo contacts. The same structure is adopted by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium(II) Bromide
Vanadium(II) bromide is a inorganic compound with the formula VBr2. It adopts the cadmium iodide structure, featuring octahedral V(II) centers. A hexahydrate is also known. The hexahydrate undergoes partial dehydration to give the tetrahydrate. Both the hexa- and tetrahydrates are bluish in color. The compound is produced by the reduction of vanadium(III) bromide with 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 .... Further reading *Stebler, A.; Leuenberger, B.; Guedel, H. U. "Synthesis and crystal growth of A3M2X9 (A = Cs, Rb; M = Ti, V, Cr; X = Cl, Br)" Inorganic Syntheses (1989), volume 26, pages 377–85. References {{Bromides Bromides Metal halides Vanadium(II) compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep Mantle (geology), mantle remain active areas of investigation. All allotropes (structurally different pure forms of an element) and some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, graphene, etc.), carbon monoxide , carbon dioxide , carbides, and salt (chemistry), salts of inorganic anions such as carbonates, cyanides, cyanates, thiocyanates, isothiocyanates, etc. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it cannot occur within life, living things. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordination Polymers
Coordination may refer to: * Coordination (linguistics), a compound grammatical construction * Coordination complex, consisting of a central atom or ion and a surrounding array of bound molecules or ions ** A chemical reaction to form a coordination complex * Coordination number or ligancy of a central atom in a molecule or crystal is the number of atoms, molecules or ions bonded to it * Language coordination, the tendency of people to mimic the language of others * Coordination (political culture), a Utopian form of political regime * Motor coordination, in animal motion * ''Gleichschaltung'' the process of Nazification in Germany after 1933, often translated as "coordination" See also * Coordinate (other) Coordinate may refer to: * An element of a coordinate system in geometry and related domains ** Coordinate space in mathematics ** Cartesian coordinate system ** Coordinate (vector space) ** Geographic coordinate system * Coordinate structure in ... * Coordinator ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium Tetrachloride
Vanadium tetrachloride is the inorganic compound with the formula V Cl4. This reddish-brown liquid serves as a useful reagent for the preparation of other vanadium compounds. Synthesis, bonding, basic properties With one more valence electron than diamagnetic TiCl4, VCl4 is a paramagnetic liquid. It is one of only a few paramagnetic compounds that is liquid at room temperature. VCl4 is prepared by chlorination of vanadium metal. VCl5 does not form in this reaction; Cl2 lacks the oxidizing power to attack VCl4. VCl5 can however be prepared indirectly from VF5 at −78 °C. Reactions Consistent with its high oxidizing power, VCl4 reacts with HBr at -50 °C to produce VBr3. The reaction proceeds via VBr4, which releases Br2 during warming to room temperature. :2 VCl4 + 8 HBr → 2 VBr3 + 8 HCl + Br2 VCl4 forms adducts with many donor ligands, for example, VCl4(THF)2. It is the precursor to vanadocene dichloride. Organic chemistry In organic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Bromide
Hydrogen bromide is the inorganic compound with the formula . It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room temperature. Aqueous solutions that are 47.6% HBr by mass form a constant-boiling azeotrope mixture that boils at . Boiling less concentrated solutions releases H2O until the constant-boiling mixture composition is reached. Hydrogen bromide, and its aqueous solution, hydrobromic acid, are commonly used reagents in the preparation of bromide compounds. Reactions Organic chemistry Hydrogen bromide and hydrobromic acid are important reagents in the production of organobromine compounds.Greenwood, N. N.; Earnshaw, A. Chemistry of the Elements; Butterworth-Heineman: Oxford, Great Britain; 1997; pp. 809–812.Vollhardt, K. P. C.; Neil E. Schore, Schore, N. E. Organic Chemistry: Structure and Function; 4th Ed.; W. H. Freeman and Company: New York, N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromine
Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It 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 , referring to its sharp and pungent smell. Elemental bromine is very reactive and thus does not occur as a free element in nature. Instead, it can be isolated from colourless soluble crystalline mineral halide Ionic salt, salts analogous to table salt, a property it shares with the other halogens. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br) has caused its Bromine cycle, accumulation in the oceans. Commercially the element is easily extracted from brine evaporation ponds, mostly in the United States and Israel. The mass of bromine in the oce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium(III) Chloride
Vanadium(III) chloride describes the inorganic compound with the formula VCl3 and its hydrates. It forms a purple anhydrous form and a green hexahydrate Cl2(H2O)4l·2H2O. These hygroscopic salts are common precursors to other vanadium(III) complexes and is used as a mild reducing agent. Structure and electronic configuration VCl3 has the common layered BiI3 structure, a motif that features hexagonally closest-packed chloride framework with vanadium ions occupying the octahedral holes. VBr3 and VI3 adopt the same structure, but VF3 features a structure more closely related to ReO3. The V3+cation has a ''d''2 electronic configuration with two unpaired electrons, making the compound paramagnetic.Greenwood, N. N. and Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. p. 990 . VCl3 is a Mott insulator and undergoes an antiferromagnetic transition at low temperatures. Solid hexahydrate, Cl2(H2O)4l·2H2O, has a monoclinic crystal structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordination Complex
A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many metal-containing chemical compound, compounds, especially those that include transition metals (elements like titanium that belong to the periodic table's d-block), are coordination complexes. Nomenclature and terminology Coordination complexes are so pervasive that their structures and reactions are described in many ways, sometimes confusingly. The atom within a ligand that is bonded to the central metal atom or ion is called the donor atom. In a typical complex, a metal ion is bonded to several donor atoms, which can be the same or different. A Ligand#Polydentate and polyhapto ligand motifs and nomenclature, polydentate (multiple bonded) ligand is a molecule or ion that bonds to the central atom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
