Azomethane

Structural formula
	;
	cis - (top) or trans -azomethane (bottom)
General
Surname	Azomethane
other names	Dimethyldiimide; 1,2-dimethyldiazene;
Molecular formula	C 2 H 6 N 2
Brief description	colorless to pale yellow gas
External identifiers / databases
EC number	685-709-9
ECHA InfoCard	100.211.415
PubChem	10421
Wikidata	Q793997
properties
Molar mass	58.082 g mol −1
Melting point	−78 ° C (trans) ; −66 ° C (cis)
boiling point	1.5 ° C (trans) ; 95 ° C (cis)
Vapor pressure	1001 hPa (trans, 0 ° C)
safety instructions
H and P phrases	H: 220-280
	P: ?
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Azomethane is a colorless to slightly yellowish explosive gas and the simplest organic azo compound .

Extraction and presentation

Azomethane can be produced in good yield from 1,2-dimethylhydrazine by careful oxidation, for example with copper (II) chloride .

properties

There are two isomers of azomethane :

cis -azomethane, according to IUPAC : (Z) -azomethane
trans -azomethane, according to IUPAC: (E) -azomethane.

The trans isomer is 42 k J / mol more stable than the cis compound. At temperatures above 0 ° C, azomethane tautomerizes to formaldehyde methylhydrazone (CH ₃ NHN = CH ₂ ).

Tautomerization

use

The difficult handling of the connection stands in the way of a larger technical application. In the laboratory, azomethane can be used to generate methyl radicals . During pyrolysis, two methyl radicals are briefly formed in addition to the thermodynamically very stable nitrogen.

{\ displaystyle {\ ce {CH_3-N = N-CH_3 -> N_2 + 2 CH_3 ^ {.}}}}

Biological importance

During the metabolism of the highly carcinogenic 1,2-dimethylhydrazine , azomethane is formed as an intermediate product through oxidation in the liver .

literature

K. Wolter: Vibration spectroscopic investigations on a transition metal oxide / metal model catalyst system. Dissertation, TU Berlin, 2001, urn : nbn: de: kobv: 83-opus-3167 .
KS Khuong and KN Houk : One-bond, two-bond, and three-bond mechanisms in thermal deazetizations of 2,3-diazabicyclo [2.2.2] oct-2-enes, trans-azomethane, and 2,3-diazabicyclo [ 2.2.1] hept-2-ene. In: Journal of the American Chemical Society . Volume 125, 2003, pp. 14867-14883, PMID 14640664 .
EW Diau and AH Zewail : Femtochemistry of trans-azomethane: a combined experimental and theoretical study. In: ChemPhysChem. Volume 4, 2003, pp. 445-456, PMID 12785258 .
P. Cattaneo and M. Persico: Semiclassical simulations of azomethane photochemistry in the gas phase and in solution. In: Journal of the American Chemical Society. Vol. 123, 2001, pp. 7638-7645, PMID 11480986 .
NJ Gerria and F. Kaufman: The explosive decomposition of azomethane. In: Symposium (International) on Combustion. Volume 10, 1965, pp. 227-235, doi : 10.1016 / S0082-0784 (65) 80167-9 .
OK Rice: The Theory of the Decomposition of Azomethane. In: Proceedings of the National Academy of Sciences . Volume 14, 1928, pp. 118-124, PMC 1085389 (free full text).

Individual evidence

↑ Azomethane Lexicon of Chemistry
↑ ^a ^b ^c ^d Martin N. Ackermann, Norman C. Craig, Ralph R. Isberg, David M. Lauter, Richard A. MacPhail, William G. Young: cis-Dimethyldiazene . In: Journal of the American Chemical Society . tape 99 , no. 5 , 1977, pp. 1661–1663 , doi : 10.1021 / ja00447a072 .
^ H. Henkin, H. Austin Taylor: The Viscosity and Molecular Diameter of Azomethane . In: Journal of Chemical Physics . tape 7 , no. 9 , 1939, pp. 829-830 , doi : 10.1063 / 1.1750533 .
↑ Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of (E) -dimethyldiazenes in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on December 16, 2019, is reproduced from a self-classification by the distributor .
^ Francis P. Jahn: The Preparation of Azomethane. In: Journal of the American Chemical Society . Volume 59, 1937, pp. 1761-1762, doi : 10.1021 / ja01288a502 .
^ I. Vrabel et al .: Stationary Points on the Ground-State Potential Energy Surface of Dimethyldiazene. Isomerization and Decomposition in Competition. In: Journal of Physical Chemistry A . Volume 101, 1997, pp. 5805-5812, doi : 10.1021 / jp970702j .
↑ MN Ackermann et al .: Vibrational Spectra of cis-Dimethyldiazene-d0 -1,1,1-d3, and -d6. In: The Journal of Physical Chemistry. Volume 83, 1979, pp. 1190-1200, doi : 10.1021 / j100472a017 .
↑ RS Zhai et al .: Chemisorption and reaction characteristics of methyl radicals on Cu (110). In: Langmuir . Volume 20, 2004, pp. 3623-2631, PMID 15875392 .
^ S. Wolter and N. Frank: Metabolism of 1,2-dimethylhydrazine in isolated perfused rat liver. In: Chemico-Biological Interactions . Volume 42, 1982, pp. 335-244, PMID 7151235 .

[lex-1] Azomethane Lexicon of Chemistry

[Ackermann-2] Martin N. Ackermann, Norman C. Craig, Ralph R. Isberg, David M. Lauter, Richard A. MacPhail, William G. Young: cis-Dimethyldiazene . In: Journal of the American Chemical Society . tape 99 , no. 5 , 1977, pp. 1661–1663 , doi : 10.1021 / ja00447a072 .

[3] H. Henkin, H. Austin Taylor: The Viscosity and Molecular Diameter of Azomethane . In: Journal of Chemical Physics . tape 7 , no. 9 , 1939, pp. 829-830 , doi : 10.1063 / 1.1750533 .

[4] Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of (E) -dimethyldiazenes in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on December 16, 2019, is reproduced from a self-classification by the distributor .

[5] Francis P. Jahn: The Preparation of Azomethane. In: Journal of the American Chemical Society . Volume 59, 1937, pp. 1761-1762, doi : 10.1021 / ja01288a502 .

[6] I. Vrabel et al .: Stationary Points on the Ground-State Potential Energy Surface of Dimethyldiazene. Isomerization and Decomposition in Competition. In: Journal of Physical Chemistry A . Volume 101, 1997, pp. 5805-5812, doi : 10.1021 / jp970702j .

[7] MN Ackermann et al .: Vibrational Spectra of cis-Dimethyldiazene-d0 -1,1,1-d3, and -d6. In: The Journal of Physical Chemistry. Volume 83, 1979, pp. 1190-1200, doi : 10.1021 / j100472a017 .

[8] RS Zhai et al .: Chemisorption and reaction characteristics of methyl radicals on Cu (110). In: Langmuir . Volume 20, 2004, pp. 3623-2631, PMID 15875392 .

[9] S. Wolter and N. Frank: Metabolism of 1,2-dimethylhydrazine in isolated perfused rat liver. In: Chemico-Biological Interactions . Volume 42, 1982, pp. 335-244, PMID 7151235 .