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Vanadium Oxydichloride
Vanadium oxydichloride is the inorganic compound with the formula VOCl2. One of several oxychlorides of vanadium, it is a hygroscopic green solid. It is prepared by comproportionation of vanadium trichloride and vanadium(V) oxides: :V2O5 + VOCl3 + 3 VCl3 → 6 VOCl2 As verified by X-ray crystallography, vanadium oxydichloride adopts a layered structure, featuring octahedral vanadium centers linked by doubly bridging oxide and chloride ligands. From VOCl2, various blue or green-colored oxotri- and oxotetrachloride salts can be prepared. Examples include N(CH3)4VOCl3 and the pyridinium Pyridinium refers to the cation . It is the conjugate acid of pyridine. Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines. They are prepared by treating pyridine with acids. As pyridine is oft ... derivative (C5H5NH)2VOCl4. References {{Vanadium compounds Vanadium(IV) compounds Oxychlorides Metal halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that 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 remain active areas of investigation. Some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon ( graphite, diamond, buckminsterfullerene, etc.), carbon monoxide, carbon dioxide, carbides, and the following salts of inorganic anions: carbonates, cyanides, cyanates, and thiocyanates. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it does not occur within living things. History Friedrich Wöhler's conversion of ammonium cyanate into urea in 1828 is often cited as the starting p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxychloride
In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula , where X = fluorine (F), chlorine (Cl), bromine (Br), and/or iodine (I). The element A may be a main group element, a transition element or an actinide. The term ''oxohalide'', or ''oxyhalide'', may also refer to minerals and other crystalline substances with the same overall chemical formula, but having an ionic structure. Synthesis Oxohalides can be seen as compounds intermediate between oxides and halides. There are three general methods of synthesis: *Partial oxidation of a halide: *:2 PCl3 + O2 -> 2 POCl3 **In this example, the oxidation state increases by two and the electrical charge is unchanged. *Partial halogenation of an oxide: *:2 V2O5 + 6 Cl2 + 3 C -> 4 VOCl3 + 3 CO2 *Oxide replacement: *: rO42- + 2 Cl- + 4 H+ -> CrO2Cl2 + 4 H2O In addition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comproportionation
Comproportionation or synproportionation 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 disproportionation.Shriver, D. F.; Atkins, P. W.; Overton, T. L.; Rourke, J. P.; Weller, M. T.; Armstrong, F. A. “Inorganic Chemistry” W. H. Freeman, New York, 2006. . Frost diagrams The tendency of two species to disproportionate or comproportionate can be determined by examining the Frost diagram of the oxidation states; if a species' value of Δ''G''/''F'' is lower than the line joining the two oxidation numbers on either side of it, then it is more stable and if in a solution, these two species will undergo comproportionation. A Frost Diagram is another way of displaying the reduction potentials for the various oxidation states of a given element, X. It shows nE against the oxidation number N: here, E is the reduction potential for the X(N)/X(0) c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium Trichloride
Vanadium trichloride is the inorganic compound with the formula VCl3. This purple salt is a common precursor to other vanadium(III) complexes. Structure VCl3 has the common 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. VCl3 is paramagnetic and has two unpaired electrons. Preparation and reactions VCl3 is prepared by heating VCl4 at 160–170 °C under a flowing stream of inert gas, which sweeps out the Cl2. The bright red liquid converts to a purple solid. Heating of VCl3 decomposes with volatilization of VCl4, leaving VCl2. Upon heating under H2 at 675 °C (but less than 700 °C), VCl3 reduces to greenish VCl2. :: 2 VCl3 + H2 → 2 VCl2 + 2 HCl Comproportionation of vanadium trichloride and vanadium(V) oxides gives vanadium oxydichloride: :V2O5 + VOCl3 + 3 VCl3 → ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridinium
Pyridinium refers to the cation . It is the conjugate acid of pyridine. Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines. They are prepared by treating pyridine with acids. As pyridine is often used as an organic base in chemical reactions, pyridinium salts are produced in many acid-base reactions. Its salts are often insoluble in the organic solvent, so precipitation of the pyridinium leaving group complex is an indication of the progress of the reaction. Pyridinium cations are aromatic, as determined through Hückel's rule. They are isoelectronic with benzene. ''N''-Alkylpyridinium cations When the acidic proton is replaced by alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloal ..., the compounds are called ''N''-alky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium(IV) Compounds
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer ( passivation) somewhat stabilizes the free metal against further oxidation. Spanish scientist Andrés Manuel del Río discovered compounds of vanadium in 1801 in Mexico by analyzing a new lead-bearing mineral he called "brown lead". Though he initially presumed its qualities were due to the presence of a new element, he was later erroneously convinced by French chemist Hippolyte Victor Collet-Descotils that the element was just chromium. Then in 1830, Nils Gabriel Sefström generated chlorides of vanadium, thus proving there was a new element, and named it "vanadium" after the Scandinavian goddess of beauty and fertility, Vanadís (Freyja). The name was based on the wide range of colors found in vanadium compounds. Del Rio's lead mineral was u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
