Question

What are triphenylmethane dyes? Give examples.

Answer 1

Before knowing about triphenylmethane dyes, we have to get an idea about them. A dye is a coloured substance that has an affinity to the substrate to which it is being applied. It is an aromatic compound.

Complete step by step solution:
As we know dyes are coloured substances that have an affinity to the substrate to which it is being applied. Now talk about triphenylmethane dyes, triphenylmethane dyes are amino derivatives of triphenylmethane, or it is the basic skeleton of many synthetic dyes called triphenylmethane dyes. Malachite is an example of triphenylmethane dyes. It is used to colour wool and silk.
Preparation of triphenylmethane dyes: It can be synthesized by friedel-Craft reaction from and chloroform with aluminium chloride catalyst. The reaction for this process given below;
$$ $3{C_6}{H_6} + CHC{l_3}\xrightarrow{{AlC{l_3}}}P{h_3}CH + 3HCl$

Additional information:
Triphenylmethane dyes are brilliant intense coloured synthetic organic dyes that have molecular structures based upon hydrocarbon triphenylmethane, it has poor resistance to light and chemical bleaches due to poor resistance to light and chemical bleaches triphenylmethane used mainly in copying paper, printing and hectrograph inks and it is also used in textile applications.

Note:
Dyes are classified on the source from which it is made. Accordingly the classification could be: Natural and synthetic dyes.
Natural dyes: These dyes are dyes derived from plants, invertebrates and minerals, Example of natural dyes are roots, berries, bark, leaves and wood.
Synthetic dyes: These dyes are derived from chemical reactions of chemicals. Synthetic dyes are used everywhere in everything from clothes to paper, from food to wood, Example of synthetic dyes are acid dyes, Azo dyes and basic dyes.