Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. A hydroxide attached to a strongly electropositive center may itself ionize, liberating a hydrogen cation (H+), making the parent compound an acid.
A ketene is an organic compound of the form R′R″C=C=O, where R and R' are two arbitrary monovalent chemical groups. The name may also refer to the specific compound ethenone H
2C=C=O, the simplest ketene.
An acid dissociation constant, Ka, is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction
Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid, is a weak acid with the chemical formula H
3PO
4. It is normally encountered as a colorless syrup of 85% concentration in water. The pure compound is a colorless solid.
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon). Elemental fluorine is produced from it. Solutions of HF are colourless, acidic and highly corrosive. It is commonly used to etch glass and silicon wafers.
An isocyanide is an organic compound with the functional group -N≡C. It is the isomer of the related nitrile (-C≡N), hence the prefix is isocyano. The organic fragment is connected to the isocyanide group through the nitrogen atom, not via the carbon. They are used as building blocks for the synthesis of other compounds.
Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.
Phosphorous acid, is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in the preparation of other phosphorus compounds. Organic derivatives of phosphorous acid, compounds with the formula RPO3H2, are called phosphonic acids.
Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group R−N+
2X−
where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halogen.
Fluorosulfuric acid (IUPAC name: sulfurofluoridic acid) is the inorganic compound with the chemical formula HSO3F. It is one of the strongest acids commercially available. The formula HSO3F emphasizes its relationship to sulfuric acid, H2SO4; HSO3F is a tetrahedral molecule. It is a colourless liquid, although commercial samples are often yellow.
Fluoroboric acid or tetrafluoroboric acid (archaically, fluoboric acid) is an inorganic compound with the chemical formula [H+][BF4-], where H+ represents the solvated proton. The solvent can be any suitably Lewis basic entity. For instance, in water, it can be represented by H
3OBF
4 (oxonium tetrafluoroborate), although more realistically, several water molecules solvate the proton: [H(H2O)n+][BF4-]. The ethyl ether solvate is also commercially available: [H(Et2O)n+][BF4-], where n is most likely 2. Unlike strong acids like H2SO4 or HClO4, the pure unsolvated substance does not exist (see below).
Lithium carbide, Li
2C
2, often known as dilithium acetylide, is a chemical compound of lithium and carbon, an acetylide. It is an intermediate compound produced during radiocarbon dating procedures. Li
2C
2 is one of an extensive range of lithium-carbon compounds which include the lithium-rich Li
4C, Li
6C
2, Li
8C
3, Li
6C
3, Li
4C
3, Li
4C
5, and the graphite intercalation compounds LiC
6, LiC
12, and LiC
18.
Li
2C
2 is the most thermodynamically-stable lithium-rich compound and the only one that can be obtained directly from the elements. It was first produced by Moissan, in 1896 who reacted coal with lithium carbonate.
Disilyne is a silicon hydride with the formula Si
2H
2. Several isomers are possible, but none are sufficiently stable to be of practical value. Substituted disilynes contain a formal silicon–silicon triple bond and as such are sometimes written R2Si2 (where R is a substituent group). They are the silicon analogues of alkynes.
Disulfur difluoride is a halide of sulfur, with the chemical formula S2F2.
Difluorophosphate or difluorodioxophosphate or phosphorodifluoridate is an anion with formula PO
2F−
2. It has a single negative charge and resembles perchlorate (ClO−
4) and monofluorosulfonate (SO3F−) in shape and compounds. These ions are isoelectronic, along with tetrafluoroaluminate, phosphate, orthosilicate, and sulfate. It forms a series of compounds. The ion is toxic to mammals as it causes blockage to iodine uptake in the thyroid. However it is degraded in the body over several hours.
Fluorophosphoric acid is the inorganic compound with the formula H2PO3F. It is a colorless viscous liquid that solidified to a glass upon cooling.
Difluorophosphoric acid is an inorganic compound with the formula HPO2F2. It is a colorless liquid. The acid has limited applications, in part because it is thermally and hydrolytically unstable.
The Nickel ternary chalcogenides are a class of chemical compounds that contains nickel, a chalcogenide, and another element. Nickel forms a series of double nickel oxides with other elements, which may be termed "nickelates". These double nickel oxides are not listed on this page. There are also many well defined double compounds with sulfur, selenium and tellurium which are listed here.
The telluride phosphides are a class of mixed anion compounds containing both telluride and phosphide ions. The phosphidotelluride or telluridophosphide compounds have a [TeP]3− group in which the tellurium atom has a bond to the phosphorus atom. A formal charge of −2 is on the phosphorus and −1 on the tellurium. There is no binary compound of tellurium and phosphorus. Not many telluride phosphides are known, but they have been discovered for noble metals, actinides, and group 4 elements.
Peroxymonophosphoric acid is an oxyacid of phosphorus. Its salts are called peroxymonophosphates. It is one of two known peroxyphosphoric acids, along with peroxydiphosphoric acid.
