The Chemical Structure and Functional Properties of Caffeine

Amirali Banani

December 26, 2022

The chemical structure of Caffeine (1,3,7-Trimethylpurine-2,6-dione) and its key functional properties.

Breakdown of Caffeine’s Chemical Name:

• 1,3,7-Trimethyl = 3 methyl (CH3) groups on the 1st, 3rd and 7th carbon atoms
• purine = the bicyclic structure (two carbon rings fused together) of the molecule
• 2,6-dione = two ketone functional groups (hence the name “dione”) on the 2nd and 6th carbon atoms

Functional Properties of Caffeine

The ketone group in Caffeine is the functional group that yields both its lipophilic and hydrophilic properties. These characteristics allow this organic molecule to surpass the blood-brain barrier and enter the brain, where it passes through interstitial fluid and binds to adenosine receptors, blocking hormones such as melatonin from eliciting their effects on the body. This is essentially the reason that caffeine keeps you awake, alert, and energetic throughout the day. Additionally, caffeine’s hydrophilicity allows the molecule to be removed by chemical solvents — such as ethyl acetate or methylene chloride — in the decaffeination process to produce decaffeinated coffee. ☕️🧠💦