chem: Add nitriles

docs/snc4mz.md

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 The course code for this page is **SNC4MZ**.
 
-CHEM!
-
 ## Organic chemistry
 
 !!! definition
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 !!! example
     <img src="/resources/images/amide-names.png" width=700>(Source: Kognity)</img>
 
+### Nitriles
+
+Nitriles consist of a cyanide(s) attached at the end of a carbon chain.
+
+$$\ce{R-C#N}$$
+
+As they can only be placed at the end of a carbon chain, a positional number is not used. These have the highest priority of all organic compounds and use the suffix **-nitrile** and the prefix **cyano-**.
+
+!!! example
+    - methanenitrile
+    - methanedinitrile
+
+Nitriles are synthesised through the nucleophilic substitution of halogenoalkanes, **extending their carbon chain**.
+$$\ce{R-X + C#N- -> R-C#N + X-}$$
+
+### Reduction reactions
+
+### Retro-synthesis
+
+### Simple polymers
+
+### Polyesters and polyamides
+
+### Stereoisomers
+
 ### Properties of organic compounds
 
 **Alcohols** are able to form hydrogen bonds, so are soluble in water. Increasing the length of the main chain decreases solubility as the rest of the molecule is non-polar, but this can be compensated by adding more hydroxyls too.