Hexamethylbenzene

• Mellitol
• Melliten

Orthorhombic prisms or needles

Fixed

1.042 g · cm -3

165.5 ° C

263.4 ° C

Insoluble in water, soluble in ethanol, ether, acetone, benzene, chloroform, acetic acid and

Template: Infobox chemical / molecular formula search available

Hexamethylbenzene ( Mellitol, Melliten ) is a substituted benzene with six methyl groups and thus an aromatic hydrocarbon.

History and characteristics

In 1880, observed J. Le Bel and WH Greene, that in the reaction of methanol molten zinc chloride and hexamethylbenzene was formed.

The reaction was interpreted as dehydrocyclization of ethylene to benzene with subsequent Friedel -Crafts alkylation with methyl chloride.

Hexamethylbenzene is a solid that forms orthorhombic prisms or needles. The melting point is 165.5 ° C, making it the highest of the methyl-substituted benzenes.

The trivial name is derived from the Mellitol mellitic ( benzenehexacarboxylic ), which in turn was isolated from mellit (honey stone). In the same way, it is derived from the common name of 1,2,3- trimethylbenzene ( Hemellitol, Hemi - Mellitol ). The hemi - syllable denotes here the half of substituents.

In 1929 Kathleen Lonsdale proved for the first time the shape of the Hexamethylbenzols and thus showed that the benzene ring is hexagonal and flat.

Representation

For displaying a solution of phenol in methanol over an extended period on an activated alumina catalyst, 530 ° C, is added dropwise.

Use

Because it is rich in electrons, hexamethylbenzene can be used as a ligand in organometallic chemistry. It is used in various organometallic syntheses, for example, titanium, chromium, cobalt, rhodium and rhenium. Two other examples from the organoruthenium chemistry are the sandwich complexes Ru ( ɳ4 - C6 ( CH3 ) 6) ( ɳ6 - C6 ( CH3 ) 6) and the dication [ Ru ( ɳ6 - C6 ( CH3 ) 6) 2] 2 .

Hexamethylbenzene is also used as a solvent for the 3He NMR spectroscopy.