Tetranitromethane

Tetranitromethane
Tetranitromethane
General
Abbreviations	NSC 16146, TNM
Chem. formula	C (NO 2 ) 4
Rat formula	CN 4 O 8
Physical properties
condition	colorless liquid
Molar mass	196.04 g / mol
Density	1,63944 g / cm³
Thermal properties
T. melt.	14.2 ° C
T. bale.	125.7 ° C
T. aux.	113 ° C
Enthalpy of Education	–37.29 kJ / mol
Steam pressure	8.4 mmHg Art.
Optical properties
Refractive index	1.4467
Classification
Reg. CAS number	509-14-8
PubChem
Reg. EINECS number
Smiles
Inchi
Reg. EC number	208-094-7
RTECS	PB4025000
Chebi
UN number
ChemSpider
Security
LD 50	130 mg / kg, rat, orally
Toxicity	toxic
R phrases	R8 , R25 , R26 , R36 / 37/38 , R40
S-phrases	S17 , S28 , S36 / 37 , S45
H phrases	H271 , H301 , H319 , H330 , H335 , H351
P-phrases	P220 , P260 , P281 , P284 , P301 + P310 , P305 + P351 + P338
Signal word	Dangerous
GHS icons
NFPA 704	one 3 2 Ox

Tetranitromethane (obsolete name: nitroform ) is a chemical compound with the formula C (NO ₂ ) ₄ related to aliphatic nitro compounds . The tetranitromethane molecule is symmetrical and has the shape of a tetrahedron , in the center of which there is a carbon atom, and at the top there are four nitro groups NO ₂ . Under normal conditions, pure tetranitromethane is a colorless, oily liquid with a pungent odor. It can be used as a strong oxidizing agent or nitrating agent ; therefore, it is mainly used in the chemical industry and as a component of rocket fuels. In mixtures with other organic substances, it forms highly sensitive and powerful explosives . Toxic by inhalation and in contact with skin.

Content

1 Physical properties
2 Chemical properties
3 Getting
- 3.1 Destructive nitration of acetic anhydride
- 3.2 Destructive nitration of acetylene
4 Application
5 Security
6 Toxicity
7 notes
8 Literature
9 References

Physical Properties

Tetranitromethane is a colorless, oily, highly volatile liquid with a pungent odor. In various directories, the physicochemical parameters of tetranitromethane differ; This section contains data accepted by the International Bureau of Physicochemical Standards and presented in the review on the chemistry of tetranitromethane in 1976 ^[1] . Density at 20 ° C: 1.63944 g / cm ³ . Melting point: 13.9 ° C, boiling point at normal pressure: 127.5 ° C.

It does not dissolve in water, nor does it dissolve in sulfuric acid and polyhydric alcohols. Soluble in a large number of organic solvents and in concentrated nitric acid. During distillation, it partially decomposes; it is distilled with water vapor.

Chemical Properties

Due to the presence of four nitro groups in one molecule, tetranitromethane is a strong oxidizing agent. Pure tetranitromethane is a weak explosive, however, with organic substances it forms explosive mixtures, the power of which is greater than that of nitroglycerin.

Tetranitromethane in water or alcohol solutions of alkalis undergoes hydrolysis with the formation of trinitromethane or its salts:

{\mathsf {C(NO_{2})_{4}+H_{2}O\rightleftarrows CH(NO_{2})_{3}+HNO_{3}}}

{\ displaystyle {\ mathsf {C (NO_ {2}) _ {4} + H_ {2} O \ rightleftarrows CH (NO_ {2}) _ {3} + HNO_ {3}}}}

{\mathsf {C(NO_{2})_{4}+KOH+C_{2}H_{5}OH\rightarrow C(NO_{2})_{3}K+C_{2}H_{5}NO_{2}K+H_{2}O}}

{\ displaystyle {\ mathsf {C (NO_ {2}) _ {4} + KOH + C_ {2} H_ {5} OH \ rightarrow C (NO_ {2}) _ {3} K + C_ {2} H_ {5} NO_ {2} K + H_ {2} O}}}

Aqueous alkaline solutions completely hydrolyze tetranitromethane:

{\mathsf {C(NO_{2})_{4}+6KOH\rightarrow K_{2}CO_{3}+4KNO_{2}+3H_{2}O}}

{\ displaystyle {\ mathsf {C (NO_ {2}) _ {4} + 6KOH \ rightarrow K_ {2} CO_ {3} + 4KNO_ {2} + 3H_ {2} O}}}

Tetranitromethane in the presence of pyridine in an alkaline medium nitrates organic compounds. Under the action of tetranitromethane, copper and iron corrode, aluminum , stainless alloys and glass are stable.

However, iron is resistant to tetranitromethane if 0.2% by weight sulfuric acid is added to the latter. This circumstance allows the storage and transportation of tetranitromethane in an iron container.

Getting

It was first synthesized by the Russian chemist L. N. Shishkov in 1857 by nitration of trinitromethane ^[2] . Tetranitromethane is produced by various methods ^[3] ^[4] , among which the most famous are the destructive nitration reactions of acetylene , ketene or acetic anhydride with concentrated nitric acid .

Destructive nitration of acetic anhydride

The destructive nitration reaction of acetic anhydride proceeds according to the equation:

{\mathsf {4(CH_{3}CO)_{2}O+4HNO_{3}\rightarrow C(NO_{2})_{4}+7CH_{3}COOH+CO_{2}}}

{\ displaystyle {\ mathsf {4 (CH_ {3} CO) _ {2} O + 4HNO_ {3} \ rightarrow C (NO_ {2}) _ {4} + 7CH_ {3} COOH + CO_ {2}} }}

The reagents are mixed in a stoichiometric ratio and aged for 5-7 days at a temperature of 25-28 ° C. The product yield is 70-75%. Formed in the form of a heavy oily liquid, tetranitromethane is separated by decantation , distilled with water vapor and dried over calcium chloride . This method is convenient in the laboratory. Its disadvantage is the duration of the nitration process ^[5] . The method was also used on an industrial scale in the USA by Nitroform Products, however, in 1953 the tetranitromethane plant was completely destroyed by an explosion, the probable cause of which was an increase in temperature in the reacting mixture due to malfunction of the mixer or sensitization of the mixture with catalyst impurities ^[6] .

Destructive nitration of acetylene

The destructive nitration reaction of acetylene with concentrated nitric acid proceeds in accordance with the following global equation:

{\mathsf {5C_{2}H_{2}+38HNO_{3}\rightarrow 3C(NO_{2})_{4}+24H_{2}O+7CO_{2}+26NO_{2}}}

{\ displaystyle {\ mathsf {5C_ {2} H_ {2} + 38HNO_ {3} \ rightarrow 3C (NO_ {2}) _ {4} + 24H_ {2} O + 7CO_ {2} + 26NO_ {2}} }}

The yield of tetranitromethane is approximately 60%. This method was used during the Second World War, while the nitration process itself took place in two stages. First, acetylene was nitrated to trinitromethane, which was not isolated from the reaction mixture. Then, in the second stage, carried out with the addition of concentrated sulfuric acid, trinitromethane was converted to tetranitromethane, which was separated from the acid by separation. The reaction is carried out at a temperature of 45-50 ° C (but not higher than 60 ° C) in the presence of a catalyst ( mercury (II) nitrate ) ^[7] .

Application

In 1948, a liquid-propellant rocket engine using tetranitromethane as an oxidizing agent was tested at NII-4 of the Academy of Artillery Sciences of the USSR Ministry of Armed Forces. The supervisor of the work was N. G. Chernyshev . The specific impulse was 20% higher than that of kerosene-oxygen engines.

On September 1, 1949, a pilot plant of the Ministry of Agricultural Engineering began to work in Chapaevsk (it was it that engaged in the production of rockets in those years) for the production of tetranitromethane.

The use of tetranitromethane as rocket fuel is hindered by its high melting point.

Tetranitromethane is mainly used to produce trinitromethane and in nitration reactions in laboratory practice.

Security

Pure tetranitromethane is a weak explosive substance, insensitive to shock and other methods of initiation. However, when working with it, it is necessary to strictly observe safety measures that exclude the ingress of organic impurities into it. Mixtures of tetranitromethane with organic substances are powerful and highly sensitive explosives, extremely dangerous to handle ^[8] .

Toxicity

Tetranitromethane is a highly toxic substance. The threshold concentration in the air is 0.003 mg / l, the maximum permissible concentration is 0.001 mg / l ^[9] . If inhaled, causes respiratory irritation. With prolonged exposure, it causes methemoglobinemia , pulmonary edema , affects the liver, kidneys and central nervous system. Harmful in contact with mucous membranes and skin, with subcutaneous injection can cause tissue necrosis.

Experiments have shown that tetranitromethane pairs can cause the formation of malignant tumors in the lungs (alveolar and bronchial adenomas and carcinomas) in rats and mice. The occurrence of a rare form of cancer, was also noted. As a result of this, despite the absence of direct experimental evidence, tetranitromethane is also considered to be a carcinogen with a significant degree of probability for humans ^[10] .

Notes

↑ Altukhov, Perekalin, Chemistry of tetranitromethane, 1976 , p. 2052-2053.
↑ Altukhov, Perekalin, Chemistry of tetranitromethane, 1976 , p. 2051.
↑ Syntheses of organic preparations. Collection 3. / Ed. Acad. B.A. Kazansky. - M .: Publishing house of foreign literature, 1952. - S. 411-413. - 581 p.
↑ Poe Liang. Tetranitromethane // Org. Synth .. - 1941.- T. 21 . - S. 105 . - DOI : 10.15227 / orgsyn.021.0105 .
↑ Orlova, Chemistry and technology of high explosives and explosives, 1973 , p. 407.
↑ Urbansky, 1964 , p. 593.
↑ Urbansky, 1964 , p. 594.
↑ Orlova, Chemistry and technology of high explosives and explosives, 1973 , p. 406.
↑ Altukhov, Perekalin, Chemistry of tetranitromethane, 1976 , p. 2054.
↑ Tetranitromethane. (English) // Report on carcinogens: carcinogen profiles / US Dept. of Health and Human Services, Public Health Service, National Toxicology Program. - 2011. - Vol. 12. - P. 402-403. - PMID 21863104 .

Literature

Altukhov K.V., Perekalin V.V. Chemistry of tetranitromethane // Advances in Chemistry. - 1976. - T. 45 , No. 11 . - S. 2050-2076 .
Chemical Encyclopedia in five volumes. Paul - Three. - M .: "The Big Russian Encyclopedia", 1995. - V. 4. - S. 1102. - ISBN 5-85270-092-4 .
Kantemirov B.N. Nikolay Gavrilovich Chernyshev. - M .: Nauka, 2012 .-- 175 p. - ISBN 978-5-02-037988-6 .
Neyland O. Ya. Organic chemistry: Textbook. for chem. specialist. universities. - M .: High School, 1990. - 751 p. - ISBN 5-06-001471-1 .
Orlova E. Yu. Chemistry and technology of high explosives and explosives. - 2nd edition, revised and supplemented. - L .: Chemistry, 1973.- 688 p.
CRC Handbook of Chemistry and Physics / Ed. by D. R. Lide .. - 90th Edition. - CRC Press (Taylor and Francis Group), 2009 .-- 2804 p. - ISBN 978-1-4200-9084-0 .
Urbansky T. Chemistry and Technology of Explosives. Vol. 1 . - Pergamon Press, 1964 .-- 635 p. - ISBN 978-0080102382 .

Links

Sigma-Aldrich. IR spectrum of tetranitromethane (neopr.) . Date of treatment December 5, 2014.

[_4478ac0924a0d6d9-1] Altukhov, Perekalin, Chemistry of tetranitromethane, 1976 , p. 2052-2053.

[_178413ca98778af1-2] Altukhov, Perekalin, Chemistry of tetranitromethane, 1976 , p. 2051.

[3] Syntheses of organic preparations. Collection 3. / Ed. Acad. B.A. Kazansky. - M .: Publishing house of foreign literature, 1952. - S. 411-413. - 581 p.

[4] Poe Liang. Tetranitromethane // Org. Synth .. - 1941.- T. 21 . - S. 105 . - DOI : 10.15227 / orgsyn.021.0105 .

[_f846f226c3377f5a-5] Orlova, Chemistry and technology of high explosives and explosives, 1973 , p. 407.

[_a046db759014a691-6] Urbansky, 1964 , p. 593.

[_a046db759014a696-7] Urbansky, 1964 , p. 594.

[_f846f226c3377f5b-8] Orlova, Chemistry and technology of high explosives and explosives, 1973 , p. 406.

[_178413ca98778af4-9] Altukhov, Perekalin, Chemistry of tetranitromethane, 1976 , p. 2054.

[10] Tetranitromethane. (English) // Report on carcinogens: carcinogen profiles / US Dept. of Health and Human Services, Public Health Service, National Toxicology Program. - 2011. - Vol. 12. - P. 402-403. - PMID 21863104 .