Names | |||
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IUPAC name Nitrilooxonium | |||
Systematic IUPAC name Oxidonitrogen(1+) [1] | |||
Other names Nitrosonium Iminooxidanium | |||
Identifiers | |||
3D model (JSmol) | |||
Abbreviations | NO(+) | ||
ChEBI | |||
ChemSpider | |||
456 | |||
PubChem CID | |||
CompTox Dashboard (EPA) | |||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
The nitrosonium ion is NO+, in which the nitrogen atom is bonded to an oxygen atom with a bond order of 3, and the overall diatomic species bears a positive charge. It can be viewed as nitric oxide with one electron removed. This ion is usually obtained as the following salts: NOClO4, NOSO4H (nitrosylsulfuric acid, more descriptively written ONSO3OH) and NOBF4. The ClO−4 and BF−4 salts are slightly soluble in acetonitrile CH3CN. NOBF4 can be purified by sublimation at 200–250 °C and 0.01 mmHg (1.3 Pa). [2]
NO+ is isoelectronic with CO, CN− and N2. It arises via protonation of nitrous acid:
In its infrared spectrum of its salts, νNO is a strong peak in the range 2150-2400 cm−1. [3]
NO+ reacts readily with water to form nitrous acid:
For this reason, nitrosonium compounds must be protected from water or even moist air. With base, the reaction generates nitrite:
NO+ reacts with aryl amines, ArNH2, to give diazonium salts, ArN+2. The resulting diazonium group is easily displaced (unlike the amino group) by a variety of nucleophiles.
NO+, e.g. as NOBF4, is a strong oxidizing agent: [4]
In organic chemistry, it selectively cleaves ethers and oximes, and couples diarylamines. [5]
NOBF4 is a convenient oxidant because the byproduct NO is a gas, which can be swept from the reaction using a stream of N2. Upon contact with air, NO forms NO2, which can cause secondary reactions if it is not removed. NO2 is readily detectable by its characteristic orange color.
Electron-rich arenes are nitrosylated using NOBF4. [6] One example involves anisole:
Nitrosonium, NO+, is sometimes confused with nitronium, NO+
2, the active agent in nitrations. These species are quite different, however. Nitronium is a more potent electrophile than is nitrosonium, as anticipated by the fact that the former is derived from a strong acid (nitric acid) and the latter from a weak acid (nitrous acid).
NOBF4 reacts with some metal carbonyl complexes to yield related metal nitrosyl complexes. [7] In some cases, [NO]+ does not bind the metal nucleophile but acts as an oxidant.
Nitric acid is an inorganic compound with the formula HNO3. It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% HNO3, it is referred to as fuming nitric acid. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%.
The nitronium ion, [NO2]+, is a cation. It is an onium ion because its nitrogen atom has +1 charge, similar to ammonium ion [NH4]+. It is created by the removal of an electron from the paramagnetic nitrogen dioxide molecule NO2, or the protonation of nitric acid HNO3.
Ferrocene is an organometallic compound with the formula Fe(C5H5)2. The molecule is a complex consisting of two cyclopentadienyl rings sandwiching a central iron atom. It is an orange solid with a camphor-like odor that sublimes above room temperature, and is soluble in most organic solvents. It is remarkable for its stability: it is unaffected by air, water, strong bases, and can be heated to 400 °C without decomposition. In oxidizing conditions it can reversibly react with strong acids to form the ferrocenium cation Fe(C5H5)+2. Ferrocene and the ferrocenium cation are sometimes abbreviated as Fc and Fc+ respectively.
An oxidizing agent is a substance in a redox chemical reaction that gains or "accepts"/"receives" an electron from a reducing agent. In other words, an oxidizer is any substance that oxidizes another substance. The oxidation state, which describes the degree of loss of electrons, of the oxidizer decreases while that of the reductant increases; this is expressed by saying that oxidizers "undergo reduction" and "are reduced" while reducers "undergo oxidation" and "are oxidized". Common oxidizing agents are oxygen, hydrogen peroxide, and the halogens.
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russian rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide. Its molar mass is 92.011 g/mol.
Nitrogen dioxide is a chemical compound with the formula NO2. One of several nitrogen oxides, nitrogen dioxide is a reddish-brown gas. It is a paramagnetic, bent molecule with C2v point group symmetry. Industrially, NO2 is an intermediate in the synthesis of nitric acid, millions of tons of which are produced each year, primarily for the production of fertilizers.
In chemistry, azide is a linear, polyatomic anion with the formula N−3 and structure −N=N+=N−. It is the conjugate base of hydrazoic acid HN3. Organic azides are organic compounds with the formula RN3, containing the azide functional group. The dominant application of azides is as a propellant in air bags.
Nitrous acid is a weak and monoprotic acid known only in solution, in the gas phase, and in the form of nitrite salts. It was discovered by Carl Wilhelm Scheele, who called it "phlogisticated acid of niter". Nitrous acid is used to make diazonium salts from amines. The resulting diazonium salts are reagents in azo coupling reactions to give azo dyes.
Nitrosation and nitrosylation are two names for the process of converting organic compounds or metal complexes into nitroso derivatives, i.e., compounds containing the R−NO functionality. The synonymy arises because the R-NO functionality can be interpreted two different ways, depending on the physico-chemical environment:
Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group [R−N+≡N]X− 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 halide. The parent compound where R is hydrogen, is diazenylium.
Nitrosyl chloride is the chemical compound with the formula NOCl. It is a yellow gas that is commonly encountered as a component of aqua regia, a mixture of 3 parts concentrated hydrochloric acid and 1 part of concentrated nitric acid. It is a strong electrophile and oxidizing agent. It is sometimes called Tilden's reagent, after William A. Tilden, who was the first to produce it as a pure compound.
Silver hexafluorophosphate, sometimes referred to "silver PF-6," is an inorganic compound with the chemical formula AgPF6.
In organic chemistry, S-nitrosothiols, also known as thionitrites, are organic compounds or functional groups containing a nitroso group attached to the sulfur atom of a thiol. S-Nitrosothiols have the general formula R−S−N=O, where R denotes an organic group.
Dinitrogen trioxide is the inorganic compound with the formula N2O3. It is a nitrogen oxide. It forms upon mixing equal parts of nitric oxide and nitrogen dioxide and cooling the mixture below −21 °C (−6 °F):
Ferrocenium tetrafluoroborate is an organometallic compound with the formula [Fe(C5H5)2]BF4. This salt is composed of the cation [Fe(C5H5)2]+ and the tetrafluoroborate anion (BF−
4). The related hexafluorophosphate is also a popular reagent with similar properties. The ferrocenium cation is often abbreviated Fc+ or Cp2Fe+. The salt is deep blue in color and paramagnetic. Ferrocenium salts are sometimes used as one-electron oxidizing agents, and the reduced product, ferrocene, is inert and readily separated from ionic products. The ferrocene–ferrocenium couple is often used as a reference in electrochemistry. The standard potential of ferrocene-ferrocenium is dependent on specific electrochemical conditions.
Nitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound with the chemical formula NOBF4. This colourless solid is used in organic synthesis as a nitrosating agent, diazotizing agent and a mild oxidant.
Rhodocene is a chemical compound with the formula [Rh(C5H5)2]. Each molecule contains an atom of rhodium bound between two planar aromatic systems of five carbon atoms known as cyclopentadienyl rings in a sandwich arrangement. It is an organometallic compound as it has (haptic) covalent rhodium–carbon bonds. The [Rh(C5H5)2] radical is found above 150 °C (302 °F) or when trapped by cooling to liquid nitrogen temperatures (−196 °C [−321 °F]). At room temperature, pairs of these radicals join via their cyclopentadienyl rings to form a dimer, a yellow solid.
Zirconium nitrate is a volatile anhydrous transition metal nitrate salt of zirconium with formula Zr(NO3)4. It has alternate names of zirconium tetranitrate, or zirconium(IV) nitrate.
A transition metal nitrate complex is a coordination compound containing one or more nitrate ligands. Such complexes are common starting reagents for the preparation of other compounds.
Nitrosyl perchlorate is the inorganic compound with the formula NO(ClO4). A hygroscopic white solid, it is the salt of the nitrosonium cation with the perchlorate anion. It is an oxidant and strong electrophile, but has fallen out of use with the availability of the closely related salt nitrosonium tetrafluoroborate NO(BF4).