2-butyne

Structural formula
General
Surname	2-butyne
other names	But-2-in ( IUPAC ); Dimethylacetylene; Dimethylethine;
Molecular formula	C 4 H 6
External identifiers / databases
EC number	207-962-2
ECHA InfoCard	100.007.239
PubChem	10419
Wikidata	Q209336
properties
Molar mass	54.09 g mol −1
Physical state	liquid
density	0.69 g cm −3 (20 ° C)
Melting point	−32 ° C
boiling point	27 ° C
Vapor pressure	774 hPa (20 ° C); 1130 hPa (30 ° C); 2.165 bar (50 ° C); 3.325 bar (65 ° C);
solubility	practically insoluble in water (approx. 3.4 g l −1 )
Refractive index	1.3921 (20 ° C)
safety instructions
H and P phrases	H: 224-315-319-335
	P: 210-261-305 + 351 + 338
Thermodynamic properties
ΔH f 0	119.1 kJ / mol
	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

2-Butyne (according to IUPAC nomenclature: But-2-yne , rarely also called dimethylacetylene ) is an organic-chemical compound from the group of unsaturated , aliphatic hydrocarbons , more precisely the alkynes . With 5-decyne ( dibutylethyne ), 4-octyne ( dipropylethyne ) and 3-hexyne ( diethylethyne ), it is one of the symmetrical alkynes.

presentation

2-Butyne is obtained from the reaction of propyne with iodomethane (methyl iodide) .

properties

2-Butyne is a colorless, volatile, easily inflammable liquid at room temperature. Due to the triple bond , 2-butyne is a reactive compound; so she goes z. B. with halogen addition reactions . In 2-butyne, the triple bond is between carbon atoms 2 and 3, i.e. inside the molecule. This is why 2-butyne is called an internal alkyne. The vapor pressure function results from log (P) = 21.6295 - (2047.473 / T) - 4.8153 · log (T).

safety instructions

2-butyne is an extremely flammable and irritating substance. It can enter into violent polymerization and addition reactions .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Entry on 2-butyne in the GESTIS substance database of the IFA , accessed on April 19, 2018(JavaScript required) .
↑ 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.
↑ 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. 5-25.
↑ ^a ^b G.B. Hazy; HM Davis: Physical Constants of Dimethylacetylene . In: JACS 57 (1935), pp. 339-340, doi : 10.1021 / ja01305a031 .

Web links

Wiktionary: 2-butyne - explanations of meanings, word origins, synonyms, translations

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Entry on 2-butyne in the GESTIS substance database of the IFA , accessed on April 19, 2018(JavaScript required) .

[CRC90_3_84-2] 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.

[CRC90_5_25-3] 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. 5-25.

[Heisig-4] G.B. Hazy; HM Davis: Physical Constants of Dimethylacetylene . In: JACS 57 (1935), pp. 339-340, doi : 10.1021 / ja01305a031 .