In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P−O−P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate and tetrasodium pyrophosphate, among others. Often pyrophosphates are called diphosphates. The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid. The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond, a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P−O−P bond, and which mirrors the nomenclature for anhydrides of carboxylic acids. Pyrophosphates are found in ATP and other nucleotide triphosphates, which are important in biochemistry. The term pyrophosphate is also the name of esters formed by the condensation of a phosphorylated biological compound with inorganic phosphate, as for dimethylallyl pyrophosphate. This bond is also referred to as a high-energy phosphate bond.
Sulfur trioxide (alternative spelling sulphur trioxide, also known as nisso sulfan) is the chemical compound with the formula SO3. It has been described as "unquestionably the most important economically" sulfur oxide. It is prepared on an industrial scale as a precursor to sulfuric acid.
In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.
Manganese(III) fluoride (also known as Manganese trifluoride) is the inorganic compound with the formula MnF3. This red/purplish solid is useful for converting hydrocarbons into fluorocarbons, i.e., it is a fluorination agent. It forms a hydrate and many derivatives.
Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.
Molybdenum trioxide describes a family of inorganic compounds with the formula MoO3(H2O)n where n = 0, 1, 2. The anhydrous compound is produced on the largest scale of any molybdenum compound since it is the main intermediate produced when molybdenum ores are purified. The anhydrous oxide is a precursor to molybdenum metal, an important alloying agent. It is also an important industrial catalyst. It is a yellow solid, although impure samples can appear blue or green.
Calcium pyrophosphate (Ca2P2O7) is a chemical compound, an insoluble calcium salt containing the pyrophosphate anion. There are a number of forms reported: an anhydrous form, a dihydrate, Ca2P2O7·2H2O and a tetrahydrate, Ca2P2O7·4H2O. Deposition of dihydrate crystals in cartilage are responsible for the severe joint pain in cases of calcium pyrophosphate deposition disease (pseudo gout) whose symptoms are similar to those of gout. Ca2P2O7 is commonly used as a mild abrasive agent in toothpastes, because of its insolubility and nonreactivity toward fluoride.
Dicalcium phosphate is the calcium phosphate with the formula CaHPO4 and its dihydrate. The "di" prefix in the common name arises because the formation of the HPO42– anion involves the removal of two protons from phosphoric acid, H3PO4. It is also known as dibasic calcium phosphate or calcium monohydrogen phosphate. Dicalcium phosphate is used as a food additive, it is found in some toothpastes as a polishing agent and is a biomaterial.
Sodium orthovanadate is the inorganic compound with the chemical formula Na3V O4. It forms a dihydrate Na3VO4·2H2O. Sodium orthovanadate is a salt of the VO3−4 oxyanion. It is a colorless, water-soluble solid.
In chemistry, a vanadate is an anionic coordination complex of vanadium. Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5. The complexes [V(CN)6]3− and [V2Cl9]3− are referred to as hexacyanovanadate(III) and nonachlorodivanadate(III), respectively.
Sodium phosphide is the inorganic compound with the formula Na3P. It is a black solid. It is often described as Na+ salt of the P3− anion. Na3P is a source of the highly reactive phosphide anion. It should not be confused with sodium phosphate, Na3PO4.
Ammonium metavanadate is the inorganic compound with the formula NH4VO3. It is a white salt, although samples are often yellow owing to impurities of V2O5. It is an important intermediate in the purification of vanadium.
Vanadium(III) chloride describes the inorganic compound with the formula VCl3 and its hydrates. It forms a purple anhydrous form and a green hexahydrate [VCl2(H2O)4]Cl·2H2O. These hygroscopic salts are common precursors to other vanadium(III) complexes and is used as a mild reducing agent.
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.
Vanadium hexacarbonyl is the inorganic compound with the formula V(CO)6. It is a blue-black volatile solid. This highly reactive species is noteworthy from theoretical perspectives as a rare isolable homoleptic metal carbonyl that is paramagnetic. Most species with the formula Mx(CO)y follow the 18-electron rule, whereas V(CO)6 has 17 valence electrons.
Tetraphenylphosphonium chloride is the chemical compound with the formula [(C6H5)4P]Cl, abbreviated Ph4PCl or PPh4Cl or [PPh4]Cl, where Ph stands for phenyl. Tetraphenylphosphonium and especially tetraphenylarsonium salts were formerly of interest in gravimetric analysis of perchlorate and related oxyanions. This colourless salt is used to generate lipophilic salts from inorganic and organometallic anions. Thus, [Ph4P]+ is useful as a phase-transfer catalyst, again because it allows inorganic anions to dissolve in organic solvents.
Barium borate is an inorganic compound, a borate of barium with a chemical formula BaB2O4 or Ba(BO2)2. It is available as a hydrate or dehydrated form, as white powder or colorless crystals. The crystals exist in the high-temperature α phase and low-temperature β phase, abbreviated as BBO; both phases are birefringent, and BBO is a common nonlinear optical material.
Sodium decavanadate describes any member of the family of inorganic compounds with the formula Na6[V10O28](H2O)n. These are sodium salts of the orange-colored decavanadate anion [V10O28]6−. Numerous other decavanadate salts have been isolated and studied since 1956 when it was first characterized.
Vanadium phosphates are inorganic compounds with the formula VOxPO4 as well related hydrates with the formula VOxPO4(H2O)n. Some of these compounds are used commercially as catalysts for oxidation reactions.
Manganese oxalate is a chemical compound, a salt of manganese and oxalic acid with the chemical formula MnC
2O
4. The compound creates light pink crystals, does not dissolve in water, and forms crystalline hydrates. It occurs naturally as the mineral Lindbergite.
![Chain of tetrahedral vanadate [VO4] units, each sharing two corners Ammonium-metavanadate-chains-3D.png](http://upload.wikimedia.org/wikipedia/commons/thumb/7/76/Ammonium-metavanadate-chains-3D.png/200px-Ammonium-metavanadate-chains-3D.png)
