Names | |||
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IUPAC name Tetranitromethane | |||
Other names TNM Tetan | |||
Identifiers | |||
3D model (JSmol) | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.007.359 | ||
EC Number |
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KEGG | |||
PubChem CID | |||
RTECS number |
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UNII | |||
UN number | 1510 | ||
CompTox Dashboard (EPA) | |||
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Properties | |||
C(NO2)4 | |||
Molar mass | 196.04 g/mol | ||
Appearance | Colorless to pale-yellow liquid or solid | ||
Odor | Pungent | ||
Density | 1.623 g/cm3 | ||
Melting point | 13.8 °C (56.8 °F; 286.9 K) | ||
Boiling point | 126 °C (259 °F; 399 K) | ||
insoluble | |||
Vapor pressure | 8 mmHg (20°C) [2] | ||
-43.02·10−6 cm3/mol | |||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards | Oxidant, can form explosive mixtures | ||
GHS labelling: | |||
Danger | |||
H271, H301, H315, H319, H330, H335, H351 | |||
P201, P202, P210, P220, P221, P260, P261, P264, P270, P271, P280, P281, P283, P284, P301+P310, P302+P352, P304+P340, P305+P351+P338, P306+P360, P308+P313, P310, P312, P320, P321, P330, P332+P313, P337+P313, P362, P370+P378, P371+P380+P375, P403+P233, P405, P501 | |||
NFPA 704 (fire diamond) | |||
Lethal dose or concentration (LD, LC): | |||
LC50 (median concentration) | 18 ppm (rat, 4 hr) 100 ppm (cat, 20 min) 54 ppm (mouse, 4 hr) [3] | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 1 ppm (8 mg/m3) [2] | ||
REL (Recommended) | TWA 1 ppm (8 mg/m3) [2] | ||
IDLH (Immediate danger) | 4 ppm [2] | ||
Safety data sheet (SDS) | ICSC 1468 | ||
Related compounds | |||
Related compounds | Hexanitroethane Octanitropentane Trinitromethane | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Tetranitromethane or TNM is an organic oxidizer with chemical formula C(NO2)4. Its chemical structure consists of four nitro groups attached to one carbon atom. In 1857 it was first synthesised by the reaction of sodium cyanoacetamide with nitric acid. [4]
It has been investigated for use as an oxidizer in bipropellant rockets. Highly purified tetranitromethane cannot be made to explode, but its sensitivity is increased dramatically by oxidizable contaminants, such as anti-freezing additives. [5] The pure substance also has too high a freezing point to remain reliably molten, although the eutectic with dinitrogen tetroxide freezes at the much lower −30 °C and is less explosive than nearly-pure tetranitromethane. [6] Nevertheless, the oxidizer is still too sensitive for any effective use. [5] [6]
In the laboratory it is used as a reagent for the detection of double bonds in organic compounds and as a nitrating reagent. It has also found use as an additive to diesel fuel to increase the cetane number. [7]
TNM is a pale yellow liquid that can be prepared in the laboratory by the nitration of acetic anhydride with anhydrous nitric acid (Chattaway's method). [8] This method was attempted on an industrial scale in the 1950s by Nitroform Products Company in Newark, USA, but the entire plant was destroyed by an explosion in 1953. [9]
The first industrial scale production was started in Germany during World War II in an effort to improve the cetane number of diesel fuel. This process improved the original method, which started with acetic acid and nitric acid. [10] Without regard to yield or cost, approximately 10 tons of TNM were produced in a few weeks. However, this production process has not been used again industrially after the end of the war, because of high associated costs. [11]
For commercial use a cheaper method starting from acetylene has been used. [12] First, nitric acid containing mercuric nitrate is reduced by acetylene, resulting in trinitromethane (nitroform) and a mixture of carbon dioxide and nitrogen oxide as waste gas. The nitrogen oxides are valuable and normally recovered as nitric acid in an absorption tower. The resulting nitroform is converted to TNM by adding nitric and sulfuric acid at higher temperatures. With this method a yield of 90% (based on nitric acid) before purification can be reached. [13]
TNM is a prime example of molecular flexibility. It brought structural methods to the limits of their applicability as is shown by the fact that the structure of TNM was attempted to be determined for a period of more than 70 years in various phases. [14]
Early investigations by gas electron diffractions were unable to describe the observed diffraction pattern in full and only the application of a four-dimensional model concerning the correlated movement of the four NO2 groups about the C–N bonds was able to describe the experimental observations fully. The problem occurs, because the two-fold local symmetry of the C−NO2 units versus the three-fold symmetry of the C(NO2)3 unit, as well as the close proximity of the NO2 groups hindering their free rotation, is the source for a very complicated mutually hindered movement of the NO2 groups.
The crystal structure has also been attempted several times. A first decent solution of the problem required a model describing a highly disordered high‐temperature crystalline phase of a high-temperature phase (>174.4 K) as is shown in Figure 1. Reduction of symmetry and analysis of the twinning of the crystals led finally to a resolved disorder of the structure shown in Figure 2.
The structure of an ordered low‐temperature phase contains three independent molecules in the asymmetric unit. Structural parameters of the gaseous and solid phases are listed in the following table for comparison.
Parameter | GED | XRD (range) |
rC–N | 1.509(5) | 1.502(4) – 1.554(5) |
rN–O(eclip) | 1.201(3) | 1.198(4) – 1.215(5) |
rN–O(stag) | 1.199(3) | 1.178(5) – 1.222(4) |
∡NCN_1 | 105.1(16) | 108.2(3) – 110.9(3) |
∡NCN_2 | 111.7(8) | 107.3(3) – 111.4(2) |
∡NCN_3 | 106.6(2) – 107.1(3) | |
∡ONO | 129.2(17) | 128.0(4) – 132.3(4) |
The ability of TNM to detonate is greatly affected by the presence of impurities, even in small quantities. TNM forms extremely powerful explosive mixtures when fuels are added in stoichiometric proportions. Many of these mixtures show sensitivity to impact even higher than that of nitroglycerine. [15]
Tetranitromethane can be used as a component of highly explosive liquid explosives as an oxidizing agent. It forms highly explosive mixtures with all flammable substances. When experimenting with this substance, paper filters should not be used for filtration. Even small impurities make tetranitromethane an explosive that explodes on impact or friction. A tragic lecture experiment at the University of Münster in 1920 is well known, where a small steel tube containing tetranitromethane, toluene and absorbent cotton detonated shortly before burning out in such a way that more than 30 students were injured, some seriously; [16] however, on the basis of the rector's office records, as many as 10 deaths and more than a dozen injuries are documented. [17] Thereupon the German Chemical-technical Reichsanstalt determined a detonation speed of 9300 meters per second. Alfred Stettbacher then proved comparatively that this mixture was far more explosive than hexogen, pentrite, blasting gelatine or panclastite and thus represented the most destructive explosive of all.
TNM reacts with moisture at elevated pH to produce trinitromethane (nitroform) which reacts easily with metals to form highly unstable and explosive salts. [18]
Tetranitromethane is highly toxic. Absorption of as little as 2.5 mg/kg can cause methemoglobinemia, pulmonary edema, and damage to liver, kidney, and central nervous system. It is reasonably expected to be a human carcinogen. [19]
Nitric acid is the 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%.
Trinitrotoluene, more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagent in chemical synthesis, but it is best known as an explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard comparative convention of bombs and asteroid impacts. In chemistry, TNT is used to generate charge transfer salts.
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.
Oleum, or fuming sulfuric acid, is a term referring to solutions of various compositions of sulfur trioxide in sulfuric acid, or sometimes more specifically to disulfuric acid.
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.
Nitromethane, sometimes shortened to simply "nitro", is an organic compound with the chemical formula CH
3NO
2. It is the simplest organic nitro compound. It is a polar liquid commonly used as a solvent in a variety of industrial applications such as in extractions, as a reaction medium, and as a cleaning solvent. As an intermediate in organic synthesis, it is used widely in the manufacture of pesticides, explosives, fibers, and coatings. Nitromethane is used as a fuel additive in various motorsports and hobbies, e.g. Top Fuel drag racing and miniature internal combustion engines in radio control, control line and free flight model aircraft.
Copper(II) nitrate describes any member of the family of inorganic compounds with the formula Cu(NO3)2(H2O)x. The hydrates are blue solids. Anhydrous copper nitrate forms blue-green crystals and sublimes in a vacuum at 150-200 °C. Common hydrates are the hemipentahydrate and trihydrate.
Dinitrogen pentoxide is the chemical compound with the formula N2O5. It is one of the binary nitrogen oxides, a family of compounds that only contain nitrogen and oxygen. It exists as colourless crystals that sublime slightly above room temperature, yielding a colorless gas.
Nitrobenzene is an aromatic nitro compound and the simplest of the nitrobenzenes, with the chemical formula C6H5NO2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale from benzene as a precursor to aniline. In the laboratory, it is occasionally used as a solvent, especially for electrophilic reagents.
Hexanitrobenzene, also known as HNB, is a nitrobenzene compound in which six nitro groups are bonded to all six positions of a central benzene ring. is a high-density explosive compound with chemical formula C6N6O12, obtained by oxidizing the amine group of pentanitroaniline with hydrogen peroxide in sulfuric acid.
In organic chemistry, nitro compounds are organic compounds that contain one or more nitro functional groups. The nitro group is one of the most common explosophores used globally. The nitro group is also strongly electron-withdrawing. Because of this property, C−H bonds alpha (adjacent) to the nitro group can be acidic. For similar reasons, the presence of nitro groups in aromatic compounds retards electrophilic aromatic substitution but facilitates nucleophilic aromatic substitution. Nitro groups are rarely found in nature. They are almost invariably produced by nitration reactions starting with nitric acid.
Decaborane, also called decaborane(14), is the borane with the chemical formula B10H14. This white crystalline compound is one of the principal boron hydride clusters, both as a reference structure and as a precursor to other boron hydrides. It is toxic and volatile, giving off a foul odor, like that of burnt rubber or chocolate.
Barium nitrate is the inorganic compound with the chemical formula Ba(NO3)2. It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics.
Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds.
Arsenic pentoxide is the inorganic compound with the formula As2O5. This glassy, white, deliquescent solid is relatively unstable, consistent with the rarity of the As(V) oxidation state. More common, and far more important commercially, is arsenic(III) oxide (As2O3). All inorganic arsenic compounds are highly toxic and thus find only limited commercial applications.
Hexanitroethane (HNE) is an organic compound with chemical formula C2N6O12 or (O2N)3C-C(NO2)3. It is a solid matter with a melting point of 135 °C.
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):
Trinitromethane, also referred to as nitroform, is a nitroalkane and oxidizer with chemical formula HC(NO2)3. It was first obtained in 1857 as the ammonium salt by the Russian chemist Leon Nikolaevich Shishkov (1830–1908). In 1900, it was discovered that nitroform can be produced by the reaction of acetylene with anhydrous nitric acid. This method went on to become the industrial process of choice during the 20th century. In the laboratory, nitroform can also be produced by hydrolysis of tetranitromethane under mild basic conditions.
Titanium nitrate is the inorganic compound with formula Ti(NO3)4. It is a colorless, diamagnetic solid that sublimes readily. It is an unusual example of a volatile binary transition metal nitrate. Ill defined species called titanium nitrate are produced upon dissolution of titanium or its oxides in nitric acid.
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.