|
Hyponitrite
In chemistry, hyponitrite may refer to the anion ( N=NOsup>2−), or to any ionic compound that contains it. In organic chemistry, it may also refer to the group −O−N=N−O−, or any organic compound with the generic formula R1−O−N=N−O−R2, where R1 and R2 are organic groups.M. N. Hughes (1968), "Hyponitrites". Quarterly Reviews of the Chemical Society, volume 22, issue 1, pages 1–13. . Such compounds can be viewed as salts and esters of respectively hyponitrous acid or HON=NOH. An acid hyponitrite is an ionic compound with the anion ( ON=NOsup>−). Hyponitrite ion Hyponitrite exhibits cis–trans isomerism.Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier The ''trans'' (''E'') form is generally found in hyponitrite salts such as sodium hyponitrite () and silver(I) hyponitrite (). The ''cis'' (''Z'') form of sodium hyponitrite can be obtained too, and it is more reactive than the ''trans'' form. The ''cis'' hyponitrite anion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hyponitrite
Sodium hyponitrite is a solid ionic compound with formula or ()2[ON=NO]2−.Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier There are ''cis'' and ''trans'' forms of the hyponitrite ion . The ''trans'' form is more common, but the ''cis'' form can be obtained too, and it is more reactive than the ''trans'' form. ''Trans'' isomer The ''trans'' isomer is colorless and soluble in water and insoluble in ethanol and diethyl ether, ether.Trambaklal Mohanlal Oza, Rajnikant Hariprasad Thaker (1955), "The Thermal Decomposition of Silver Hyponitrite". Journal of the American Chemical society, volume 77, issue 19, pages 4976–4980. Preparation Sodium hyponitrite (''trans'') is conventionally prepared by reduction (chemistry), reduction of sodium nitrite with sodium amalgam. :2 NaNO2 + 4 Na(Hg) + 2 H2O → Na2N2O2 + 4 NaOH + 4 Hg Sodium hyponitrite (''trans'') was prepared in 1927 by A. W. Scott by reacting alkyl nitrites, hydroxylammonium chloride, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver(I) Hyponitrite
Silver hyponitrite is an ionic compound with formula Ag2N2O2 or ()2 N=NOsup>2−, containing monovalent silver cations and hyponitrite anions. It is a bright canary yellow solid practically insoluble in water and most organic solvents, including DMF and DMSO.Trambaklal Mohanlal Oza, Rajnikant Hariprasad Thaker (1955), "The Thermal Decomposition of Silver Hyponitrite". Journal of the American Chemical society, volume 77, issue 19, pages 4976–4980. G. David Mendenhall (1974), "Convenient synthesis of silver hyponitrite". Journal of the American Chemical society, volume 96, issue 15, page 5000. Preparation The compound was described in 1848.(1848), "On the formation of hyponitrite of silver". Philosophical Magazine Series 3, XIII. Intelligence and miscellaneous articles, volume 33 (1848), issue 219, page 75. The salt can be precipitated from a solution of sodium hyponitrite in water by the addition of silver nitrate: : + 2 → + 2 Excess silver nitrate yields a brown or bla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyponitrous Acid
Hyponitrous acid is a chemical compound with formula or HON=NOH. It is an isomer of nitramide, H2N−NO2; and a formal dimer of azanone, HNO. Hyponitrous acid forms two series of salts, the hyponitrites containing the N=NOsup>2− anion, and the "acid hyponitrites" containing the ON=NOsup>− anion. Structure and properties There are two possible structures of hyponitrous acid, ''trans'' and ''cis''. ''trans''-Hyponitrous acid forms white crystals that are explosive when dry. In aqueous solution, it is a weak acid (p''K''a1 = 7.21, p''K''a2 = 11.54), and decomposes to nitrous oxide and water with a half life of 16 days at 25 °C at pH 1–3: : → + Since this reaction is not reversible, should not be considered as the anhydride of . The ''cis'' acid is not known, but its sodium salt can be obtained. Preparation Hyponitrous acid (''trans'') can be prepared from silver(I) hyponitrite and anhydrous HCl in ether: : + 2 HCl → + 2 AgCl Spectroscopic data indicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyponitrous Acid
Hyponitrous acid is a chemical compound with formula or HON=NOH. It is an isomer of nitramide, H2N−NO2; and a formal dimer of azanone, HNO. Hyponitrous acid forms two series of salts, the hyponitrites containing the N=NOsup>2− anion, and the "acid hyponitrites" containing the ON=NOsup>− anion. Structure and properties There are two possible structures of hyponitrous acid, ''trans'' and ''cis''. ''trans''-Hyponitrous acid forms white crystals that are explosive when dry. In aqueous solution, it is a weak acid (p''K''a1 = 7.21, p''K''a2 = 11.54), and decomposes to nitrous oxide and water with a half life of 16 days at 25 °C at pH 1–3: : → + Since this reaction is not reversible, should not be considered as the anhydride of . The ''cis'' acid is not known, but its sodium salt can be obtained. Preparation Hyponitrous acid (''trans'') can be prepared from silver(I) hyponitrite and anhydrous HCl in ether: : + 2 HCl → + 2 AgCl Spectroscopic data indicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radical (chemistry)
In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize. Most organic radicals have short lifetimes. A notable example of a radical is the hydroxyl radical (HO·), a molecule that has one unpaired electron on the oxygen atom. Two other examples are triplet oxygen and triplet carbene (꞉) which have two unpaired electrons. Radicals may be generated in a number of ways, but typical methods involve redox reactions. Ionizing radiation, heat, electrical discharges, and electrolysis are known to produce radicals. Radicals are intermediates in many chemical reactions, more so than is apparent from the balanced equations. Radicals are important in combustion, atmospheric chemistry, polymerization, plasma chemistry, biochemistry, and many other chemical processes. A majority of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxoanion
An oxyanion, or oxoanion, is an ion with the generic formula (where A represents a chemical element and O represents an oxygen atom). Oxyanions are formed by a large majority of the chemical elements. The formulae of simple oxyanions are determined by the octet rule. The corresponding oxyacid of an oxyanion is the compound . The structures of condensed oxyanions can be rationalized in terms of AO''n'' polyhedral units with sharing of corners or edges between polyhedra. The oxyanions (specifically, phosphate and polyphosphate esters) adenosine monophosphate (AMP), adenosine diphosphate ( ADP) and adenosine triphosphate (ATP) are important in biology. Monomeric oxyanions The formula of monomeric oxyanions, , is dictated by the oxidation state of the element A and its position in the periodic table. Elements of the first row are limited to a maximum coordination number of 4. However, none of the first row elements has a monomeric oxyanion with that coordination number. Instead, carbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrate
Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zero. The term molecule may or may no ... with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in water. An example of an insoluble nitrate is bismuth oxynitrate. Structure The ion is the conjugate acid, conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a formal charge of −1. This charge results from a combination formal charge in which each of the three oxygens carries a − charge, whereas the nitrogen carries a +1 charge, all these adding up to formal c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrite
The nitrite polyatomic ion, ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite also refers to organic compounds having the –ONO group, which are esters of nitrous acid. Production Sodium nitrite is made industrially by passing a mixture of nitrogen oxides into aqueous sodium hydroxide or sodium carbonate solution: : The product is purified by recrystallization. Alkali metal nitrites are thermally stable up to and beyond their melting point (441 °C for KNO2). Ammonium nitrite can be made from dinitrogen trioxide, N2O3, which is formally the anhydride of nitrous acid: :2 NH3 + H2O + N2O3 → 2 NH4NO2 Structure The nitrite ion has a symmetrical structure (C2v molecular point group, symmetry), with both N–O bonds having equal length and a bond angle of about 115°. In valence bond theory, it is des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Group
In organic chemistry, an ethyl group (abbr. Et) is an alkyl substituent with the formula , derived from ethane (). ''Ethyl'' is used in the International Union of Pure and Applied Chemistry's nomenclature of organic chemistry for a saturated two-carbon moiety in a molecule, while the prefix "''eth-''" is used to indicate the presence of two carbon atoms in the molecule. Ethylation Ethylation is the formation of a compound by introduction of the ethyl group. The most widely practiced example of this reaction is the ethylation of benzene with ethylene to yield ethylbenzene, a precursor to styrene, which is a precursor to polystyrene. Approximately 24.7 million tons of ethylbenzene were produced in 1999. :: Many ethyl-containing compounds are generated by electrophilic ethylation, i.e. treatment of nucleophiles with sources of Et+. Triethyloxonium tetrafluoroborate t3OF4 is such a reagent. For good nucleophiles, less electrophilic reagents are employed, such as ethyl h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxynitrite
Peroxynitrite (sometimes called peroxonitrite) is an ion with the formula ONOO−. It is a structural isomer of nitrate, Preparation Peroxynitrite can be prepared by the reaction of superoxide with nitric oxide: : It is prepared by the reaction of hydrogen peroxide with nitrite: : H2O2 + → ONOO− + H2O Its presence is indicated by the absorbance at 302 nm (pH 12, ''ε''302 = 1670 M−1 cm−1). Reactions Peroxynitrite is weakly basic with a p''K''a of ~6.8. It is reactive toward DNA and proteins. ONOO− reacts nucleophilically with carbon dioxide. ''In vivo'', the concentration of carbon dioxide is about 1 mM, and its reaction with ONOO− occurs quickly. Thus, under physiological conditions, the reaction of ONOO− with carbon dioxide to form nitrosoperoxycarbonate () is by far the predominant pathway for ONOO−. homolyzes to form carbonate radical and nitrogen dioxide, again as a pair of caged radicals. Approximately 6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxynitrate
Peroxynitrate (or peroxonitrate) refers to salts of the unstable peroxynitric acid, HNO4. Peroxynitrate is unstable and decomposes to nitrate and dioxygen. No solid peroxynitrate salts are known. However, there is a report that the Russian chemist Sebastian Moiseevich Tanatar produced sodium peroxynitrate octahydrate ( NaNO3. H2O2.8H2O) by evaporating a solution of sodium nitrate and hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ... until crystallisation begins and then mixing with alcohol to form crystals of the octahydrate. References Oxyanions {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
