Techniques to Identify Products of Electrophilic Aromatic Substitution (EAS) Reactions

When scientists study how certain chemical reactions happen, they use some cool tools to find out what products are made. Here are some important techniques they use:

1. Nuclear Magnetic Resonance (NMR) Spectroscopy:

   • This tool helps us understand what’s happening around hydrogen atoms in a molecule.
   • By looking at chemical shifts, scientists can figure out the substitution patterns, which can vary slightly between 0.1 and 0.2 parts per million.

2. Mass Spectrometry:

   • This technique tells us the weight of the produced molecules.
   • It can also show how the molecules break apart with a very small difference of up to 0.01 daltons.

3. Infrared (IR) Spectroscopy:

   • This helps identify special groups within the molecules.
   • When different substitutions occur, it can change the results by 10 to 20 cm$^{-1}$.

4. Chromatography (like GC or HPLC):

   • This method helps separate different products so scientists can analyze them better.
   • It can produce very pure samples, up to 99% purity for the isolated compounds.

All these techniques work together to help scientists study EAS products. They confirm what the structures look like and how they are put together.