Mesitylene

Structural formula
General
Surname	Mesitylene
other names	1,3,5-trimethylbenzene; sym -trimethylbenzene;
Molecular formula	C 9 H 12
Brief description	colorless liquid with an oily aromatic odor
External identifiers / databases
EC number	203-604-4
ECHA InfoCard	100.003.278
PubChem	7947
Wikidata	Q425161
properties
Molar mass	120.19 g mol −1
Physical state	liquid
density	0.87 g cm −3 (20 ° C)
Melting point	−45 ° C
boiling point	165 ° C
Vapor pressure	2.69 hPa (20 ° C); 5.06 hPa (30 ° C); 9.09 hPa (40 ° C); 15.7 hPa (50 ° C);
solubility	heavy in water (0.02 g l −1 at 25 ° C); soluble in ethanol and diethyl ether ;
Refractive index	1.49937 (20 ° C)
safety instructions
H and P phrases	H: 226-304-315-319-335-411
	P: 210-273-301 + 310-331-302 + 352-304 + 340 + 312
MAK	20 ml m −3 or 100 mg m −3
	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

Mesitylene ( 1,3,5-trimethylbenzene ) is a benzene substituted with three methyl groups and thus an alkylbenzene and an aromatic hydrocarbon . With its isomers hemellitol (1,2,3-trimethylbenzene) and pseudocumene (1,2,4-trimethylbenzene) it belongs to the group of trimethylbenzenes and also to the group of C ₃ -benzenes .

history

Mesitylene was first made in 1837 by Irish chemist Robert Kane by heating acetone with concentrated sulfuric acid. He named the new substance “mesitylene” because the German chemist Carl Reichenbach had called acetone “mesite” (from the Greek μεσίτης , the mediator ” ); and Kane believed that his reaction had dehydrated mesite, converting it to an alkene called "mesitylene". But Kane's determination of the chemical composition of the mesitylene was incorrect. The correct empirical formula was found by August Wilhelm von Hofmann in 1849. In 1866, Adolf von Baeyer showed that the structure of mesitylene corresponds to that of 1,3,5-trimethylbenzene. The conclusive proof that mesitylene was identical to 1,3,5-trimethylbenzene was provided by Albert Ladenburg in 1874.

The compounds mesitol ( 2,4,6-trimethylphenol ) and mesidine ( 2,4,6-trimethylaniline ), among others, are derived from mesitylene in terms of name and structure .

Occurrence and representation

Mesitylene is found in petroleum and coal tar . It is obtained from acetone by distillation with sulfuric acid.

properties

Physical Properties

Mesitylene is a colorless liquid with a melting point of −45 ° C and a boiling point of 165 ° C at normal pressure . According to Antoine, the vapor pressure function results from log ₁₀ (P) = A− (B / (T + C)) (P in bar, T in K) with A = 4.19927, B = 1569.622 and C = −63.572 in the temperature range from 354.64 to 438.87 K. It has an oily aromatic odor. It is insoluble in water; it is readily soluble in benzene , ether and ethanol .

Safety-related parameters

Mesitylene forms flammable vapor-air mixtures above the flash point temperature. The compound has a flash point of 44 ° C. The explosion range is between 0.96% by volume (48 g / m ³ ) as the lower explosion limit (LEL) and 7.3% by volume (365 g / m ³ ) as the upper explosion limit (UEL). According to the vapor pressure function, the lower explosion point is 39 ° C. The limit gap width was determined to be 0.98 mm. This results in an assignment to explosion group IIA. The ignition temperature is 550 ° C. The substance therefore falls into temperature class T1.

use

Mesitylene is used as a solvent for resins and rubber as well as for organic synthesis (e.g. of antioxidants). Mesitylene sulfochloride can be obtained by reaction with sulfuryl chloride and aluminum chloride .

Health hazards

Inhalation and ingestion lead to drowsiness, headache, cough, fatigue and sore throat. The substance irritates the skin (it is degreased by the substance), eyes and respiratory organs. The vapors have a narcotic effect in higher concentrations.

literature

HW Earhart, Andrew P. Komin: Polymethylbenzenes . In: Kirk-Othmer Encyclopedia of Chemical Technology , 2000, doi: 10.1002 / 0471238961.1615122505011808.a01

Web links

Commons : Mesitylene - collection of images, videos and audio files

Entry on mesitylene . In: P. J. Linstrom, W. G. Mallard (Eds.): NIST Chemistry WebBook, NIST Standard Reference Database Number 69 . National Institute of Standards and Technology , Gaithersburg MD, accessed December 30, 2012.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q Entry on 1,3,5-trimethylbenzene in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
^ Entry on mesitylene. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2014.
↑ 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. 3-504.
↑ Entry on mesitylene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers and / or distributors can expand the harmonized classification and labeling .
^ Robert Kane: On a Series of Combinations derived from Pyroacetic Spirit . In: Transactions of the Royal Irish Academy , 1839, 18, pp. 99–125 ( limited preview in Google book search).
↑ C. Reichenbach: About mesite (vinegar spirit) and wood spirit . In: Annalen der Pharmacie , 1834, 10 (3), pp. 298-314 ( limited preview in the Google book search).
^ Henry E. Roscoe: A Treatise on Chemistry . D. Appleton and Co., New York NY 1889, Vol. III, p. 102, footnote 2.
^ AW Hofmann: On the Composition of Mesitilole, and some of its derivatives . In: The Quarterly Journal of the Chemical Society of London , 1849, 2, pp. 104-115 ( limited preview in Google book search). (Note: The empirical formula of mesitylene - as stated in Hofmann's paper with C ₁₈ H ₁₂ - is wrong, because Hofmann used the 6 as the atomic weight of carbon instead of the correct atomic weight of 12. As soon as the correct atomic weight is used in Hofmann's calculations , his results give the correct molecular formula of C ₉ H _12. )
^ Adolf von Baeyer: About the Condensationsproducte des Acetons . In: Annalen der Chemie und Pharmacie , 1866, 140, pp. 297–306 ( limited preview in the Google book search).
↑ Albert Ladenburg: About the Mesitylene . In: Reports of the German Chemical Society , 1874, 7, pp. 1133–1137 ( digitized on Gallica ).
↑ R. Adams, RW Hufferd: mesitylenes In: Organic Synthesis . 2, 1922, p. 41, doi : 10.15227 / orgsyn.002.0041 ; Coll. Vol. 1, 1941, p. 341 ( PDF ).
↑ Forziati, AF; Norris, WR; Rossini, FD: Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons in J. Res. Natl. Bur. Stand. (US) 43 (1949) pp. 555-563 ( doi: 10.6028 / jres.043.050 ).
^ ^A ^b ^c ^d E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
↑ A. Töhl, O. Eberhard: About the action of sulfuryl chloride on aromatic hydrocarbons . In: Ber. German Chem. Ges. Volume 26 , 1893, pp. 2940-2945 , doi : 10.1002 / cber.189302603118 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q Entry on 1,3,5-trimethylbenzene in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .

[roempp-2] Entry on mesitylene. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2014.

[CRC-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. 3-504.

[CLP_100.003.278-4] Entry on mesitylene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers and / or distributors can expand the harmonized classification and labeling .

[5] Robert Kane: On a Series of Combinations derived from Pyroacetic Spirit . In: Transactions of the Royal Irish Academy , 1839, 18, pp. 99–125 ( limited preview in Google book search).

[6] C. Reichenbach: About mesite (vinegar spirit) and wood spirit . In: Annalen der Pharmacie , 1834, 10 (3), pp. 298-314 ( limited preview in the Google book search).

[7] Henry E. Roscoe: A Treatise on Chemistry . D. Appleton and Co., New York NY 1889, Vol. III, p. 102, footnote 2.

[8] AW Hofmann: On the Composition of Mesitilole, and some of its derivatives . In: The Quarterly Journal of the Chemical Society of London , 1849, 2, pp. 104-115 ( limited preview in Google book search). (Note: The empirical formula of mesitylene - as stated in Hofmann's paper with C ₁₈ H ₁₂ - is wrong, because Hofmann used the 6 as the atomic weight of carbon instead of the correct atomic weight of 12. As soon as the correct atomic weight is used in Hofmann's calculations , his results give the correct molecular formula of C ₉ H _12. )

[9] Adolf von Baeyer: About the Condensationsproducte des Acetons . In: Annalen der Chemie und Pharmacie , 1866, 140, pp. 297–306 ( limited preview in the Google book search).

[10] Albert Ladenburg: About the Mesitylene . In: Reports of the German Chemical Society , 1874, 7, pp. 1133–1137 ( digitized on Gallica ).

[11] R. Adams, RW Hufferd: mesitylenes In: Organic Synthesis . 2, 1922, p. 41, doi : 10.15227 / orgsyn.002.0041 ; Coll. Vol. 1, 1941, p. 341 ( PDF ).

[12] Forziati, AF; Norris, WR; Rossini, FD: Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons in J. Res. Natl. Bur. Stand. (US) 43 (1949) pp. 555-563 ( doi: 10.6028 / jres.043.050 ).

[Brandes-13] A ^b ^c ^d E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.

[14] A. Töhl, O. Eberhard: About the action of sulfuryl chloride on aromatic hydrocarbons . In: Ber. German Chem. Ges. Volume 26 , 1893, pp. 2940-2945 , doi : 10.1002 / cber.189302603118 .