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Ammonium Hexafluorophosphate
Ammonium hexafluorophosphate is the inorganic compound with the formula NH4PF6. It is a white water-soluble, hygroscopic solid. The compound is a salt consisting of the ammonium cation and hexafluorophosphate anion. It is commonly used as a source of the hexafluorophosphate anion, a weakly coordinating anion. It is prepared by combining neat ammonium fluoride and phosphorus pentachloride. Alternatively it can also be produced from phosphonitrilic chloride: :PCl5 + 6 NH4F → NH4PF6 + 5 NH4Cl :PNCl2 + 6 HF → NH4PF6 + 2 HCl References [...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 point of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (), where one or more hydrogen atoms are replaced by organic groups (indicated by R). Acid–base properties The ammonium ion is generated when ammonia, a weak base, reacts with Brønsted acids (proton donors): :H+ + NH3 -> H4 The ammonium ion is mildly acidic, reacting with Brønsted bases to return to the uncharged ammonia molecule: : H4 + B- -> HB + NH3 Thus, treatment of concentrated solutions of ammonium salts with strong base gives ammonia. When ammonia is dissolved in water, a tiny amount of it converts to ammonium ions: :H2O + NH3 OH- + H4 The degree to which ammonia forms the ammonium ion depends on the pH of the solution. If the pH is low, the equilibrium shifts to the right: more ammonia molecules are co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexafluorophosphate
Hexafluorophosphate is an anion with chemical formula of . It is an octahedral species that imparts no color to its salts. is isoelectronic with sulfur hexafluoride, , and the hexafluorosilicate dianion, , and hexafluoroantimonate . In this anion, phosphorus has a valence of 5. Being poorly nucleophilic, hexafluorophosphate is classified as a non-coordinating anion. Synthesis Hexafluorophosphate salts can be prepared by the reaction of phosphorus pentachloride and alkali or ammonium halide in a solution of hydrofluoric acid: : Hexafluorophosphoric acid can be prepared by direct reaction of hydrogen fluoride with phosphorus pentafluoride. It is a strong Brønsted acid that is typically generated ''in situ'' immediately before its use. : These reactions require specialized equipment to safely handle the hazards associated with hydrofluoric acid and hydrogen fluoride. Quantitative analysis Several methods of quantitative analysis for the hexafluorophosphate ion have been de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weakly Coordinating Anion
Anions that interact weakly with cations are termed non-coordinating anions, although a more accurate term is weakly coordinating anion. Non-coordinating anions are useful in studying the reactivity of electrophilic cations. They are commonly found as counterions for cationic metal complexes with an 18-Electron rule, unsaturated coordination sphere. These special anions are essential components of Homogeneous catalysis, homogeneous Ziegler–Natta catalyst, alkene polymerisation catalysts, where the active catalyst is a coordinatively unsaturated, cationic transition metal complex. For example, they are employed as counterions for the electron counting, 14 valence electron cations [(C5H5)2ZrR]+ (R = methyl or a growing polyethylene chain). Complexes derived from non-coordinating anions have been used to catalyze hydrogenation, hydrosilylation, oligomerization, and the living polymerization of alkenes. The popularization of non-coordinating anions has contributed to increased underst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Fluoride
Ammonium fluoride is the inorganic compound with the formula NH4F. It crystallizes as small colourless prisms, having a sharp saline taste, and is highly soluble in water. Like all fluoride salts, it is moderately toxic in both acute and chronic overdose. Crystal structure Ammonium fluoride adopts the wurtzite crystal structure, in which both the ammonium cations and the fluoride anions are stacked in ABABAB... layers, each being tetrahedrally surrounded by four of the other. There are N−H···F hydrogen bonds between the anions and cations. This structure is very similar to ice, and ammonium fluoride is the only substance which can form mixed crystals with water. Reactions On passing hydrogen fluoride gas (in excess) through the salt, ammonium fluoride absorbs the gas to form the addition compound ammonium bifluoride. The reaction occurring is: :NH4F + HF → NH4HF2 It sublimes when heated—a property common among ammonium salts. In the sublimation, the salt decomposes to am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus Pentachloride
Phosphorus pentachloride is the chemical compound with the formula PCl5. It is one of the most important phosphorus chlorides, others being PCl3 and POCl3. PCl5 finds use as a chlorinating reagent. It is a colourless, water-sensitive and moisture-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride. Structure The structures for the phosphorus chlorides are invariably consistent with VSEPR theory. The structure of PCl5 depends on its environment. Gaseous and molten PCl5 is a neutral molecule with trigonal bipyramidal geometry and (''D''3h) symmetry. The hypervalent nature of this species (as well as of , see below) can be explained with the inclusion of non-bonding molecular orbitals (molecular orbital theory) or resonance (valence bond theory). This trigonal bipyramidal structure persists in nonpolar solvents, such as CS2 and CCl4. In the solid state PCl5 is an ionic compound, formulated . In solutions of polar solvents, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphonitrilic Chloride
Hexachlorophosphazene is an inorganic compound with the formula . The molecule has a cyclic, unsaturated backbone consisting of alternating phosphorus and nitrogen centers, and can be viewed as a trimer of the hypothetical compound . Its classification as a phosphazene highlights its relationship to benzene. There is large academic interest in the compound relating to the phosphorus-nitrogen bonding and phosphorus reactivity. Occasionally, commercial or suggested practical applications have been reported, too, utilising hexachlorophosphazene as a precursor chemical.Mark, J. E.; Allcock, H. R.; West, R. “Inorganic Polymers” Prentice Hall, Englewood, NJ: 1992. . Derivatives of noted interest include the hexalkoxyphosphazene lubricants obtained from nucleophilic substitution of hexachlorophosphazene with alkoxides, or chemically resistant inorganic polymers with desirable thermal and mechanical properties known as polyphosphazenes produced from the polymerisation of hexach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Compounds
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (), where one or more hydrogen atoms are replaced by organic groups (indicated by R). Acid–base properties The ammonium ion is generated when ammonia, a weak base, reacts with Brønsted acids (proton donors): :H+ + NH3 -> H4 The ammonium ion is mildly acidic, reacting with Brønsted bases to return to the uncharged ammonia molecule: : H4 + B- -> HB + NH3 Thus, treatment of concentrated solutions of ammonium salts with strong base gives ammonia. When ammonia is dissolved in water, a tiny amount of it converts to ammonium ions: :H2O + NH3 OH- + H4 The degree to which ammonia forms the ammonium ion depends on the pH of the solution. If the pH is low, the equilibrium shifts to the right: more ammonia molecules are conv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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