Triphenylmethane

• Tritan
• Triarylmethane

Crystalline, colorless solid

Fixed

1.01 g · cm -3

93 ° C.

359 ° C

• Insoluble in water
• Soluble in hot ethanol, diethyl ether and chloroform

1.5839 ( 99 ° C)

Template: Infobox chemical / molecular formula search available

Triphenylmethane also Tritan ( derived from the trityl triphenylmethyl ) referred to, is an organic compound, are grouped in the three phenyl rings to a central carbon atom. Triphenylmethane is the parent substance of the triphenylmethane dyes.

Synthesis

Triphenylmethane can be synthesized by Friedel -Crafts alkylation of benzene and trichloromethane (chloroform ), or a much better yield of benzal chloride and benzene. It is an electrophilic aromatic substitution. For both reactions, the Lewis acid is aluminum trichloride ( AlCl 3 ) is required as a catalyst. As a byproduct hydrogen chloride.

Properties

Triphenylmethane is colorless, however, in the dyes is a delocalized electron system of the appropriate cation or anion before, which is stabilized by mesomeric effect of the substituents. One then speaks of a conjugated π -electron system.

Since disrupt the hydrogen atoms of the phenyl groups spatially, a planar arrangement of the rings is not possible, they are therefore like a propeller twisted to each other before.

Triphenylmethane can be easily oxidized to triphenylmethanol. Triphenylmethane also acts as a very weak acid, for example, it can respond to Triphenylmethanid anion, which is likewise resonance-stabilized with a strong base ( alkali metals or with the elimination of hydrogen).

Use

Triphenylmethane forms the base for the group of triphenylmethane dyes ( eg indicators, textile and food dyes ). These include, inter alia, fuchsin, crystal violet, phenolphthalein, fluorescein, eosin, bromophenol blue, etc.