[danceislife]

Hello,

I am a grade 12 chemistry student, and for a culminating assignment we were told to choose a topic we are interested in and explain the chemistry behind it. It is going to be a presentation in the style of a TEDtalk as those presentations find creative ways to educate people on a topic they are passionate about. We have to relate it to the grade 12 curriculum and we have covered everything EXCEPT organic chemistry.
My presentation is going to be on the chemical reactions involved in permanent box hair dye, and after many hours of research I have realized that the only way to explain why hair color forms during the process is through organic chemistry :/ Color is formed by joining colourless molecules (a primary intermediate and a coupler) to form color during the dying process. In simplest terms, the monomers join together to create a polymer that is too large to escape the cuticle making it permanent. These are the steps involved in colouring the hair (not bleaching the hair which happens prior to this):

-The primary intermediate is oxidized by the H202
-The oxidized intermediate joins the coupler in "electrophilic aromatic substitution"
-The product of this (oxidized intermediate-coupler polymer) is oxidized to create the final hair dye

THIS IS WHAT I KNOW:

Primary intermediations are: ortho or para diaminobenzenes, aminohydoxybenzenes, and dihydroxybenzenes

Couplers are: phenols, meta distributed phenylenediamines, phenyleneaminophenols, resorcinols (1, 3-dihydroxybenzene) derivatives

Amino and hydroxy groups are rich in electrons, so when present alongside a series of double bonds this causes the molecules to become coloured.

Oxidation in terms of organic chemistry is a rxn in which a carbon atom forms more bonds to oxygen atoms or fewer bonds to hydrogen atoms.

Para, meta, and ortho have to do with positions of atoms in a compound

WHAT I WANT TO KNOW:

Oxidation a little more in depth in terms of organic chemistry and the differences compared to oxidation in electrochemistry?

Is what I said above correct?

And the main thing I need to know is, what is "electrophilic aromatic substitution"!?!?!??!?!??

I do not have to include organic chemistry in my presentation and should not go into dramatic detail if I do because we haven't learned it yet. But the only way to really understand the reactions taking place when color is formed and bonds to your hair is by looking at the organic structure of the compound and how the primary intermediates and couplers are monomers that form a polymer. I feel that just calling the second step a synthesis reaction would be bad as I am already talking about organic chemistry and my resources have been saying it is electrophilic aromatic substitution rather than synthesis. So what is electrophilic aromatic substitution and how does it relate to the chemistry in hair dye? Is it really that much different from a synthesis rxn? What is it and why is it important? THANK U IN ADVANCE!!