Names | |||
---|---|---|---|
IUPAC name Iodane [1] | |||
Other names Hydronium iodide | |||
Identifiers | |||
3D model (JSmol) | |||
ChEBI | |||
ChemSpider | |||
EC Number |
| ||
PubChem CID | |||
RTECS number |
| ||
UNII | |||
| |||
| |||
Properties | |||
HI(aq) | |||
Molar mass | 127.91 g/mol | ||
Appearance | colorless liquid | ||
Odor | acrid | ||
Density | 1.70 g/mL, azeotrope (57% HI by weight) | ||
Boiling point | 127 °C (261 °F; 400 K) 1.03 bar, azeotrope | ||
Aqueous solution | |||
Acidity (pKa) | -9.3 [2] | ||
Hazards | |||
GHS labelling: | |||
Danger | |||
H314 | |||
P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501 | |||
NFPA 704 (fire diamond) | |||
Flash point | Non-flammable | ||
Related compounds | |||
Other anions | Hydrofluoric acid Hydrochloric acid Hydrobromic acid | ||
Related compounds | Hydrogen iodide | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Hydroiodic acid (or hydriodic acid) is a colorless and aqueous solution of hydrogen iodide (HI). It is a strong acid, which is ionized completely in an aqueous solution. Concentrated solutions of hydroiodic acid are usually 48% to 57% HI. [3]
Hydroiodic acid reacts with oxygen in air to give iodine:
Like other hydrogen halides, hydroiodic acid adds to alkenes to give alkyl iodides. It can also be used as a reducing agent, for example in the reduction of aromatic nitro compounds to anilines. [4]
The Cativa process is a major end use of hydroiodic acid, which serves as a co-catalyst for the production of acetic acid by the carbonylation of methanol. [5] [6]
Hydroiodic acid is listed as a U.S. Federal DEA List I Chemical, owing to its use as a reducing agent related to the production of methamphetamine from ephedrine or pseudoephedrine (recovered from nasal decongestant pills). [7]
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is often written as R−COOH or R−CO2H, sometimes as R−C(O)OH with R referring to an organyl group, or hydrogen, or other groups. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.
Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F). The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης, meaning 'violet'.
Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula CH3COOCH3. It is a flammable liquid with a characteristically pleasant smell reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent, being weakly polar and lipophilic, but its close relative ethyl acetate is a more common solvent being less toxic and less soluble in water. Methyl acetate has a solubility of 25% in water at room temperature. At elevated temperature its solubility in water is much higher. Methyl acetate is not stable in the presence of strong aqueous bases or aqueous acids. Methyl acetate is not considered a VOC in the USA.
In chemistry, homogeneous catalysis is catalysis where the catalyst is in same phase as reactants, principally by a soluble catalyst a in solution. In contrast, heterogeneous catalysis describes processes where the catalysts and substrate are in distinct phases, typically solid-gas, respectively. The term is used almost exclusively to describe solutions and implies catalysis by organometallic compounds. Homogeneous catalysis is an established technology that continues to evolve. An illustrative major application is the production of acetic acid. Enzymes are examples of homogeneous catalysts.
Phosphorus triiodide (PI3) is an inorganic compound with the formula PI3. A red solid, it is too unstable to be stored for long periods of time; it is, nevertheless, commercially available. It is widely used in organic chemistry for converting alcohols to alkyl iodides. It is also a powerful reducing agent.
The Monsanto process is an industrial method for the manufacture of acetic acid by catalytic carbonylation of methanol. The Monsanto process has largely been supplanted by the Cativa process, a similar iridium-based process developed by BP Chemicals Ltd, which is more economical and environmentally friendly.
Hydrogen iodide (HI) is a diatomic molecule and hydrogen halide. Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a strong acid. Hydrogen iodide and hydroiodic acid are, however, different in that the former is a gas under standard conditions, whereas the other is an aqueous solution of the gas. They are interconvertible. HI is used in organic and inorganic synthesis as one of the primary sources of iodine and as a reducing agent.
The Cativa process is a method for the production of acetic acid by the carbonylation of methanol. The technology, which is similar to the Monsanto process, was developed by BP Chemicals and is under license by BP Plc. The process is based on an iridium-containing catalyst, such as the complex [Ir(CO)2I2]− (1).
Ammonium iodide is the inorganic compound with the formula NH4I. A white solid. It is an ionic compound, although impure samples appear yellow. This salt consists of ammonium cation and an iodide anion. It can be prepared by the action of hydroiodic acid on ammonia. It is easily soluble in water, from which it crystallizes in cubes. It is also soluble in ethanol. Ammonium iodide in aqueous solutions are observed as acidic and display elevated vapor pressures at high temperatures
Nickel(II) iodide is an inorganic compound with the formula NiI2. This paramagnetic black solid dissolves readily in water to give bluish-green solutions, from which crystallizes the aquo complex [Ni(H2O)6]I2 (image above). This bluish-green colour is typical of hydrated nickel(II) compounds. Nickel iodides find some applications in homogeneous catalysis.
Iodine compounds are compounds containing the element iodine. Iodine can form compounds using multiple oxidation states. Iodine is quite reactive, but it is much less reactive than the other halogens. For example, while chlorine gas will halogenate carbon monoxide, nitric oxide, and sulfur dioxide, iodine will not do so. Furthermore, iodination of metals tends to result in lower oxidation states than chlorination or bromination; for example, rhenium metal reacts with chlorine to form rhenium hexachloride, but with bromine it forms only rhenium pentabromide and iodine can achieve only rhenium tetraiodide. By the same token, however, since iodine has the lowest ionisation energy among the halogens and is the most easily oxidised of them, it has a more significant cationic chemistry and its higher oxidation states are rather more stable than those of bromine and chlorine, for example in iodine heptafluoride.
Acetyl iodide is an organoiodine compound with the formula CH3COI. It is a colourless liquid. It is formally derived from acetic acid. Although far rarer in the laboratory than the related acetyl bromide and acetyl chloride, acetyl iodide is produced, transiently at least, on a far larger scale than any other acid halide. Specifically, it is generated by the carbonylation of methyl iodide in the Cativa and Monsanto processes, which are the main industrial processes that generate acetic acid. It is also an intermediate in the production of acetic anhydride from methyl acetate.
In chemistry, carbonylation refers to reactions that introduce carbon monoxide (CO) into organic and inorganic substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry. The term carbonylation also refers to oxidation of protein side chains.
In organometallic chemistry, a migratory insertion is a type of reaction wherein two ligands on a metal complex combine. It is a subset of reactions that very closely resembles the insertion reactions, and both are differentiated by the mechanism that leads to the resulting stereochemistry of the products. However, often the two are used interchangeably because the mechanism is sometimes unknown. Therefore, migratory insertion reactions or insertion reactions, for short, are defined not by the mechanism but by the overall regiochemistry wherein one chemical entity interposes itself into an existing bond of typically a second chemical entity e.g.:
Acetic acid, systematically named ethanoic acid, is an acidic, colourless liquid and organic compound with the chemical formula CH3COOH. Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. It has been used, as a component of vinegar, throughout history from at least the third century BC.
Organorhodium chemistry is the chemistry of organometallic compounds containing a rhodium-carbon chemical bond, and the study of rhodium and rhodium compounds as catalysts in organic reactions.
An insertion reaction is a chemical reaction where one chemical entity interposes itself into an existing bond of typically a second chemical entity e.g.:
Iron(II) iodide is an inorganic compound with the chemical formula FeI2. It is used as a catalyst in organic reactions.
Allyl iodide (3-iodopropene) is an organic halide used in synthesis of other organic compounds such as N-alkyl-2-pyrrolidones, sorbic acid esters, 5,5-disubstituted barbituric acids, and organometallic catalysts. Allyl iodide can be synthesized from allyl alcohol and methyl iodide on triphenyl phosphite, Finkelstein reaction on allyl halides, or by the action of elemental phosphorus and iodine on glycerol. Allyl iodide dissolved in hexane can be stored for up to three months in a dark freezer at −5 °C (23 °F) before decomposition into free iodine becomes apparent.
Disulfur diiodide is an unstable inorganic chemical compound with the chemical formula S2I2. It is a red-brown solid that decomposes above −30 °C to elemental sulfur and iodine.