Methyl nitrite

Structural formula
General
Surname	Methyl nitrite
other names	Methyl nitrous acid
Molecular formula	CH 3 NO 2
Brief description	colorless gas
External identifiers / databases
EC number	210-870-5
ECHA InfoCard	100,009,882
PubChem	12231
Wikidata	Q2730177
properties
Molar mass	61.04 g · mol -1
Physical state	gaseous
density	0.991 g cm −3
Melting point	−40.2 ° C
boiling point	−6.42 ° C
solubility	very poorly soluble
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
Thermodynamic properties
ΔH f 0	−66.1 kJ / mol
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Methyl nitrite , is an ester of nitrous acid with methanol and is a colorless, extremely flammable and poisonous gas at room temperature. It is the most simply structured alkyl nitrite.

presentation

Methyl nitrite is formed when cold, dilute sulfuric acid acts on a water- methanol solution of sodium nitrite . Methyl nitrite (mixed with nitromethane) can also be produced by reacting silver nitrite with iodomethane .

Another manufacturing option is the addition of a mixture of nitrosylsulfuric acid and sulfuric acid in aqueous methanol.

properties

Methyl nitrite has a melting point of −40.2 ° C and a boiling point of −6.42 ° C. In the older literature these are given as −16 ° C (m.p.) and −12 ° C (b.p.). According to August, the vapor pressure function results according to lg (P) = −A / T + B (P in Torr, T in K) with A = 1365 and B = 8.102 in the temperature range from 154 K to 225 K. From the vapor pressure function a Derive the molar enthalpy of vaporization of 26.15 kJ mol ⁻¹ . As is usual with alkyl nitrites, the action of nascent hydrogen on the compound produces methanol, ammonia and water.

{\ displaystyle \ mathrm {CH_ {3} ONO \ + \ 6 [H] \ longrightarrow \ CH_ {3} OH \ + \ NH_ {3} \ + \ H_ {2} O}}

structure

At room temperature, methyl nitrite consists of a mixture of the cis - and the trans - conformer . The cis conformer is 3.13 kJ mol ^−1, more stable than the trans form. The energy barrier for the internal rotation is 45.3 kJ · mol ⁻¹ .

cis methyl nitrite	trans methyl nitrite

Explosion limits

Lower explosion limit: 5.3 vol%, 137 g / m ³
Upper explosion limit: 100% by volume, upper explosion limit does not exist as the substance decomposes.

use

For nitrosation in organic synthesis z. B. for the representation of isonitrosopropiophenone.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Entry for CAS no. 624-91-9 in the GESTIS substance database of the IFA , accessed on June 19, 2013(JavaScript required) .
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.
↑ ^a ^b L. F. Fieser, M. Fieser: Organic chemistry. 2nd edition, Verlag Chemie, 1975.
↑ Tarte, P .: Rotational Isomerism as a General Property of Alkyl Nitrites in J. Chem. Phys., 1952, 20, pp. 1570-1575. doi : 10.1063 / 1.1700218 .
^ Donald L. Pavia, Gary M. Lampman, George S. Kriz: Organic Chemistry , Volume 2. Thompson Custom Publishing, Mason, Ohio 2004, ISBN 0-03-014813-8 .
↑ ^a ^b ^c Rook, FL: Preparation, Vapor Pressure, and Infrared Spectrum of Methyl Nitrite in J. Chem. Eng. Data 27 (1982) pp. 72-73, doi : 10.1021 / je00027a022 .
^ Beyer / Walter: Textbook of Organic Chemistry , 22nd edition, S. Hirzel Verlag, Stuttgart 1991, p. 154.
↑ BJ Van der Veken, R. Maas, GA Guirgis, HD Stidham, TG Sheehan, JR Durig: Infrared spectrum, ab initio calculations, barriers to internal rotation and structural parameters for methyl nitrite . In: J. Phys. Chem. . 94, No. 10, 1990, pp. 4029-4039. doi : 10.1021 / j100373a028 .
^ Walter H. Hartung, Frank Crossley: Isonitrosopropiophenone In: Organic Syntheses . 16, 1936, p. 44, doi : 10.15227 / orgsyn.016.0044 ; Coll. Vol. 2, 1943, p. 363 ( PDF ).

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Entry for CAS no. 624-91-9 in the GESTIS substance database of the IFA , accessed on June 19, 2013(JavaScript required) .

[NV-2] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[CRC90_5_20-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.

[Fieser-4] L. F. Fieser, M. Fieser: Organic chemistry. 2nd edition, Verlag Chemie, 1975.

[5] Tarte, P .: Rotational Isomerism as a General Property of Alkyl Nitrites in J. Chem. Phys., 1952, 20, pp. 1570-1575. doi : 10.1063 / 1.1700218 .

[organic-6] Donald L. Pavia, Gary M. Lampman, George S. Kriz: Organic Chemistry , Volume 2. Thompson Custom Publishing, Mason, Ohio 2004, ISBN 0-03-014813-8 .

[Rook-7] Rook, FL: Preparation, Vapor Pressure, and Infrared Spectrum of Methyl Nitrite in J. Chem. Eng. Data 27 (1982) pp. 72-73, doi : 10.1021 / je00027a022 .

[8] Beyer / Walter: Textbook of Organic Chemistry , 22nd edition, S. Hirzel Verlag, Stuttgart 1991, p. 154.

[9] BJ Van der Veken, R. Maas, GA Guirgis, HD Stidham, TG Sheehan, JR Durig: Infrared spectrum, ab initio calculations, barriers to internal rotation and structural parameters for methyl nitrite . In: J. Phys. Chem. . 94, No. 10, 1990, pp. 4029-4039. doi : 10.1021 / j100373a028 .

[10] Walter H. Hartung, Frank Crossley: Isonitrosopropiophenone In: Organic Syntheses . 16, 1936, p. 44, doi : 10.15227 / orgsyn.016.0044 ; Coll. Vol. 2, 1943, p. 363 ( PDF ).