Dicyanoethine

Structural formula
General
Surname	Dicyanoethine
other names	2-butynedinitrile ( IUPAC ) ; Dicyanoacetylene; Dicyanoacetylene; Carbon subnitride;
Molecular formula	C 4 N 2
Brief description	colorless liquid
External identifiers / databases
PubChem	14068
ChemSpider	13449
Wikidata	Q903293
properties
Molar mass	76.06 g mol −1
Physical state	liquid
density	0.97 g cm −3
Melting point	20.5 ° C
boiling point	76.5 ° C
Vapor pressure	140 Torr (22.8 ° C)
solubility	soluble in all organic solvents
Refractive index	1.4647 (25 ° C)
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Dicyanoethine ( dicyanacetylene , butynedinitrile ) is a chemical compound that is composed only of carbon and nitrogen . As the nitrile of acetylenedicarboxylic acid , the compound can be regarded as an organic substance. It burns with up to 6100 K and thus produces the hottest currently (2012) known flame based on a chemical reaction.

It was first synthesized by Charles Moureu in 1916 .

Occurrence

Natural occurrences of dicyanoethine have been detected on Saturn's moon Titan .

Presentation and extraction

An early production method is based on the acetylenedicarboxylic acid dimethyl ester , which is first converted into the acid amide with ammonia water . Dehydration using phosphorus pentoxide gives the target compound.

properties

Physical Properties

Dicyanoethine is a clear, colorless liquid which, due to its melting point at 20.5 ° C below room temperature, solidifies to a colorless solid. The normal pressure boiling point is 76.5 ° C. The Sublimationsdruckfunktion results after August corresponding to ( P in Torr T in K) with A = 2312, and B = 10.0115 in the temperature range from -10 ° C to 20 ° C. The vapor pressure function results from ( P in Pa, T in K) with A = 51707, B = 1093.4 and C = 6.4308 in the temperature range from 22 ° C to 76 ° C. A molar enthalpy of sublimation of 44.28 kJ mol ⁻¹ , a molar evaporation enthalpy of 28.78 kJ mol ⁻¹ and a molar enthalpy of fusion of 15.49 kJ mol ⁻¹ can be derived from the sublimation and vapor pressure functions . The standard molar enthalpy of formation for the liquid is 500.4 kJ · mol ⁻¹ , the molar combustion enthalpy is –2074.4 kJ · mol ⁻¹ . ${\ displaystyle \ lg (P) = {\ frac {-A} {T}} + B}$ ${\ displaystyle \ lg (P) = {\ frac {-A} {T ^ {2}}} - {\ frac {B} {T}} + C}$

Chemical properties

Dicyanoethine is very reactive. As one of the strongest known dienophiles , it is able to enter into Diels-Alder reactions with extremely inert substances such as durol (1,2,4,5-tetramethylbenzene). When it is burned with oxygen , temperatures occur at a pressure of 1 atm up to 5260 K, at 40 atm up to 5750 K. According to calculations, the oxidation of dicyanoethine with ozone at 40 atm reaches temperatures of 6100 K and thus produces the hottest currently (2012) known flame based on a chemical reaction.

use

Dicyanoethine is used in organic synthesis as a reagent for nucleophilic addition reactions or [4 + 2] cycloaddition reactions. It can also be used as a fuel additive. Its toxic and tear-irritating effects and its explosive properties must be taken into account during handling.

Individual evidence

↑ ^a ^b ^c ^d Entry on dicyanoacetylene. In: Römpp Online . Georg Thieme Verlag, accessed on November 12, 2014.
↑ ^a ^b ^c ^d ^e ^f Saggiomo, AJ: The Dinitriles of Acetylenedicarboxylic and Polyacetylenedicarboxylic Acids. I. Dicyanoacetylene and Dicyanodiacetylene in J. Org. Chem. 22 (1957) 1171-1175, doi : 10.1021 / jo01361a009 .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-84.
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
^ RE Samuelson et al .: C ₄ N ₂ ice in Titan's north polar stratosphere. Planetary and Space Science. 45/8/1977. Pp. 941-948. doi : 10.1016 / S0032-0633 (97) 00088-3 .
↑ Moureu, C .; Bongrand, JC: Bull. Soc. Chem. (V) 846 (1909).
↑ ^a ^b e-EROS Encyclopedia of Reagents for Organic Synthesis , 1999-2013, John Wiley and Sons, Inc., entry for Dicyanoacetylene, accessed May 18, 2017 .
↑ Armstrong, GT; Marantz, S .: The heat of combustion of dicyanoacetylene in J. Phys. Chem. 64 (1960) 1776-1778, doi : 10.1021 / j100840a514 .
↑ Armstrong, GT; Marantz, S .: The heat of combustion of dicyanoacetylene [Correction Ref. 60ARM / MAR] in J. Phys. Chem. 67 (1963) 2888, doi : 10.1021 / j100806a601 .
↑ ^a ^b Kirshenbaum, AD; Grosse, AV: The Combustion of Carbon Subnitride, C ₄ N ₂ , and a Chemical Method for the Production of Continuous Temperatures in the Range of 5000-6000 ° K. in J. Am. Chem. Soc. 78 (1956) S. 2020, doi : 10.1021 / ja01590a075 .

[roempp-1] Entry on dicyanoacetylene. In: Römpp Online . Georg Thieme Verlag, accessed on November 12, 2014.

[Saggiomo-2] ↑ ^a ^b ^c ^d ^e ^f Saggiomo, AJ: The Dinitriles of Acetylenedicarboxylic and Polyacetylenedicarboxylic Acids. I. Dicyanoacetylene and Dicyanodiacetylene in J. Org. Chem. 22 (1957) 1171-1175, doi : 10.1021 / jo01361a009 .

[CRC90_3_84-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-84.

[NV-4] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[5] RE Samuelson et al .: C ₄ N ₂ ice in Titan's north polar stratosphere. Planetary and Space Science. 45/8/1977. Pp. 941-948. doi : 10.1016 / S0032-0633 (97) 00088-3 .

[6] Moureu, C .; Bongrand, JC: Bull. Soc. Chem. (V) 846 (1909).

[eEROS-7] -EROS Encyclopedia of Reagents for Organic Synthesis , 1999-2013, John Wiley and Sons, Inc., entry for Dicyanoacetylene, accessed May 18, 2017 .

[8] Armstrong, GT; Marantz, S .: The heat of combustion of dicyanoacetylene in J. Phys. Chem. 64 (1960) 1776-1778, doi : 10.1021 / j100840a514 .

[9] Armstrong, GT; Marantz, S .: The heat of combustion of dicyanoacetylene [Correction Ref. 60ARM / MAR] in J. Phys. Chem. 67 (1963) 2888, doi : 10.1021 / j100806a601 .

[Kirshenbaum-10] Kirshenbaum, AD; Grosse, AV: The Combustion of Carbon Subnitride, C ₄ N ₂ , and a Chemical Method for the Production of Continuous Temperatures in the Range of 5000-6000 ° K. in J. Am. Chem. Soc. 78 (1956) S. 2020, doi : 10.1021 / ja01590a075 .