Very few molecules have shaped the world, literally, as nitrogen containing, explosive molecules. Nitro compounds are explosive because they contain at least one NO2 molecule. NO2 is present in most well-known explosives, i.e. trinitrotoluene (TNT), picric acid, and gunpowder. When the bonds of nitrogen dioxide are broken quickly, there is a very explosive effect. This molecule is necessary for something to be explosive. There is a case where an aromatic ring has a CH3 attached and an NO2 on the other end. Another has a COOH attached to the ring and an NH2 on the other. The former is explosive and the latter is used in sunscreen. Another compound, nitroglycerin, is the glycerin molecule with three NO2 molecules on the end. Nitroglycerin is highly explosive while glycerin is not. The explosiveness of a compound is determined by the number of NO2’s attached to it. For example, dinitrotoluene has two NO2 groups and nitrotoluene only has one. The latter is less explosive than the former. There are many other nitro compounds, including more recently developed molecules, but too many to name here.
Nitro compounds have been in use for thousands of years. China, India, and Arabia were the first to use gunpowder in the thousands BC. On the contrary, the ingredients and proportions of gunpowder weren’t fully found until 1910. Gunpowder is used in firearms as the tool to propel the bullets out of the cartridge. The expanding gases push the bullet through the barrel and towards the target. The first use of gunpowder in this sense was in the early 14th century. Other nitro compounds have been used in excavation and mining. The Nobel prizes are based on the endowment of Alfred Nobel who gained his riches on nitroglycerin and dynamite. Nitroglycerin is an unstable, explosive molecule that was used in mining. However, due to nitroglycerin’s instability it was extremely dangerous to be a miner. Nobel wanted to stabilize nitroglycerin to make it safer, his brother was killed in a nitroglycerin factory explosion. So Nobel added the compound kieselguhr to a sample of nitroglycerin. This caused it to become rubbery and easy to mold. After testing, Nobel found that this combination was safe and controlled and named it dynamite after the Greek dynamis meaning power.
Explosives have also been used in warfare, exploration, and settling. Picric acid was developed to explode in shells by the French and British. TNT was used in WWI by the Germans, and then the Allies, to blow up the enemy. Fritz Haber found a way to fix nitrogen to make ammonia so TNT could be produced. This discovery led to him being awarded the 1918 Nobel Prize in Chemistry. Not for the TNT and destruction but for the amount of fertilizer that could now be made for the world. More recently there have been explosives that are more explosive and deadly than ever before. Pentaerythritoltetranitrate (PETN) is a plastic explosive that is favored by terrorists. It can be formed into any shape and is extremely hard to detect. However, after all the bad that explosives can do, it’s hard for that to outweigh the good they have done and will continue to do for the world.
I believe that nitro compounds have faded a bit from the world view. People don’t look into how explosions are made and what goes into them. Also, atomic bombs have changed the way people look at explosions. I feel that it’s no longer about the explosion or the chemistry but about the destruction. On that note, in the book Napoleon’s Buttons by Penny Le Couteur and Jay Burreson the authors focus on the real chemistry behind nitro compounds. They focus more on the chemistry and history than how destructive a bomb can be. I believe the authors did a good job displaying how nitro compounds work and their importance. They provided a few hypothetical situations that I thought were great thought stimulators and they portrayed the nitro compounds for what they really are: Tools that can be used as great resource gatherers and also tools of destruction in warfare.