2,2-dimethylpentane

Structural formula
General
Surname	2,2-dimethylpentane
Molecular formula	C 7 H 16
Brief description	highly flammable colorless liquid
External identifiers / databases
CAS number 590-35-2 EC number 209-680-5 ECHA InfoCard 100.008.801 PubChem 11542 Wikidata Q2813768
properties
Molar mass	100.21 g mol −1
Physical state	liquid
density	0.67 g cm −3
Melting point	−123 ° C
boiling point	79 ° C
Vapor pressure	111 mbar (20 ° C)
solubility	practically insoluble in water
Refractive index	1.3822 (20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 225-304-315-336-410 P: 210-261-273-301 + 310-331-501
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

2,2-Dimethylpentane is a chemical compound from the group of aliphatic saturated hydrocarbons . It is one of the nine constitutional isomers of heptane .

Extraction and presentation

2,2-Dimethylpentane can be obtained by the isomerization of n -heptane , where the compound has to be separated from the resulting mixture of isomers. A laboratory synthesis takes place via the conversion of the Grignard compound from n -propyl bromide with tert-butyl chloride .

properties

Physical Properties

2,2-Dimethylpentane is a highly flammable and colorless liquid. The vapor pressure function results according to Antoine according to log ₁₀ (P) = A− (B / (T + C)) (P in bar, T in K) with A = 3.93999, B = 1190.298 and C = −49.807 in the temperature range from 288 to 353 K.

The most important thermodynamic properties are listed in the following table:

property	Type	value
Standard enthalpy of formation	Δ f H 0 gas Δ f H 0 liquid	−206.2 kJ mol −1 −238.7 kJ mol −1
Enthalpy of combustion	Δ c H 0 liquid	−4802.6 kJ mol −1
Heat capacity	c p	221.12 J mol −1 K −1 (25 ° C) as a liquid
Enthalpy of fusion	Δ f H 0	5.824 kJ mol −1 at the melting point
Entropy of fusion	Δ f S 0	38.98 kJ mol −1 at the melting point
Enthalpy of evaporation	Δ V H 0	29.23 kJ mol −1 at the normal pressure boiling point 32.56 kJ mol −1 at 25 ° C
Critical temperature	T C	247.4 ° C
Critical pressure	P C	27.7 bar
Critical volume	V C	0.416 l mol −1
Critical density	ρ C	2.41 mol·l −1

Safety-related parameters

2,2-Dimethylpentane forms highly flammable vapor-air mixtures. The compound has a flash point of −21 ° C. The explosion range is between 0.9% by volume (40 g / m ³ ) as the lower explosion limit (LEL) and 6.9% by volume (285 g / m ³ ) as the upper explosion limit (UEL). The ignition temperature is 320 ° C. The substance therefore falls into temperature class T3.

Individual evidence

1. ↑ ^{a b c d e f g h i j} Entry on 2,2-dimethylpentane in the GESTIS substance database of the IFA , accessed on January 8, 2018(JavaScript required) .
2. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 88th edition. (Internet version: 2008), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-206.
3. ↑ Patent application US2004059174A1 : C7 + paraffin isomerization process and catalyst therefore. Published on 2004 , Inventors: J. Houzvicka, NJ Blom. ‌
4. ↑ Patent application US2004249231A1 : Isomerization catalyst and processes. Published on 2004 , Inventor: Gillespie, RD. ‌
5. ↑ Patent application US2007123745A1 : Process for the preparation of a paraffin isomerization catalys. Published on 2007 , Inventors: K. Herbst, P. Stern, NJ Blom, G. Starch-Hytoft, KG Knudsen. ‌
6. ↑ Russell E. Marker, Thomas S. Oakwood: Hexamethylethane and Tetraalkylmethanes . In: Journal of the American Chemical Society . tape 60 , no. November 11 , 1938, pp. 2598-2598 , doi : 10.1021 / ja01278a011 .
7. ↑ ^{a b c d e} Thomas E. Daubert: Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes . In: Journal of Chemical & Engineering Data . tape 41 , no. 3 , May 1996, pp. 365-372 , doi : 10.1021 / je9501548 .
8. ↑ ^{a b c} E. J. Rossini, FD Prosen: Heats of combustion and formation of the paraffinic hydrocarbons at 25 C . In: The Journal of Research of the National Institute of Standards and Technology . Vol. 34, No. 3 , 1945, p. 263-267 ( facsimile ).
9. ↑ ^{a b c} H. M. Huffman, ME Gross, DW Scott, JP McCullough: Low temperature thermodynamic properties of six isomeric heptanes . In: The Journal of Physical Chemistry . tape 65 , no. 3 , March 1961, p. 495-503 , doi : 10.1021 / j100821a026 .
10. ^ ^{A b} V. Majer, V. Svoboda: Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation . Blackwell Scientific, Oxford 1985, p. 300.
11. ↑ ^{a b} E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases . Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.