Nitro Compounds
Derivatives
of certain molecules that contain the nitrate, NO2, group, possess
an explosive potential. Whenever an explosive detonates and a massive blast
wave is produced, certain gaseous products are produced that expand rapidly and
heat is also produced; these decomposition reactions tend to be exothermic
because a lot of heat is released, which contributes to the violent explosion.
The blast wave is triggered by the instantaneous expansion of the gases that
are produced during the chemical reaction. Certain chemical reactions proceed
very violently, often including explosions and expansion of gases. The main
point of explosives is to produce a violent shock wave, which would cause
damage. The chemical reaction is supposed to proceed at a sufficient and high
enough rate in order for the expansion of the gases and the heat to occur
rapidly; if the chemical reaction does not proceed quickly enough, the
resultant gases will slowly dissipate into the atmosphere and the blast wave
will not be produced. Since many explosive molecules are based on the benzene
ring, the alternating single and double bonds alter and distort the wavelength
of absorption of the ultraviolet light; molecules such as beta-carotene
contains alternating double and single bonds, which allows the molecule to
absorb ultraviolet light at certain wavelengths and emit/reflect another
wavelength that is absorbed to the lowest extent. The explosive potential of a
molecule depends on the amount of nitrate groups attached to the parent chain
of the molecule; for example, the compound, 2,4,6-trinitrotoluene contains
three nitrate groups and has a very high explosive potential. Oxygen is
obviously required as a fuel to drive the chemical reaction yet the oxygen
present in the atmosphere will not sufficiently perform this task because the
decomposition reaction will not proceed as rapidly as expected to be applied as
weapons. The oxygen atoms have to be incorporated in the molecular structure
and have to actually be attached to the nitrogen atoms so that when the
compound is detonated, those attached oxygen atoms could quickly swap places,
attach to other atoms such as carbon atoms to form new covalent bonds and the
possibly form carbon dioxide; oxygen present in the atmosphere is “too far” to
relocate this way to produce the gases and heat efficiently enough. Guncotton
or nitrocellulose has been accidentally synthesized by Fredriech; however other
chemists considered synthesizing other explosive compounds. Ascanio Sobrero,
following this incident, studied the how nitric acid influenced certain
molecules and prepared an experiment to react glycerin and nitric acid; the
glycerin could be isolated from animal fat. Glycerol (propane-1,2,3-triol)
serves as a backbone to form a triglyceride, which is the most common form of
lipids, or fats. The resultant compound that was isolated from the reaction
solution was nitroglycerin. While handling nitroglycerin, many individuals
experienced headaches due to vasodilation; this effect has provoked the usage
of nitroglycerin to prevent heart attacks and to treat the pain caused by
angina pectoris; nitroglycerin releases the small molecule, nitric oxide, NO,
which is a powerful vasodilator, which means that it causes the blood vessels
to widen and increase the surface area. The dilation of the coronary arteries
facilitated an adequate flow of oxygenated blood to the myocardium, which
decreases the pain caused by an insufficient flow of oxygenated blood to the
heart. Nitric oxide also regulates the blood pressure and transmitting signals
between cells, aiding in digestion and the establishment of long-term memory. The
first explosive, gunpowder, has been used in China ,
Arabia, and India
to produce weapons, firecrackers, and fireworks. The chemical reaction and the
characteristics of gunpowder have been studied by people such as Roger Bacon.
The demand for nitroglycerin increased, however the substance has often been
mishandled and caused many inconveniences. Nitroglycerin was often contaminated
by the acid it was stored with and decomposed slowly, popping the containers
they were stored in. In 1866, a sample of nitroglycerin detonated in a Wells
Fargo warehouse, causing fourteen casualties. During the war, heavy artillery
and cannons contained the two explosive compounds, trinitrotoluene and
trinitrophenol. Guns could not contain such explosive compounds such as
nitroglycerin because they cannot handle the force that is exerted onto the gun
during detonation, however the explosives were launched by hand. Smokeless
gunpowder has been composed of nitroglycerin and nitrocellulose.
Trinitrotoluene and picric acid (trinitrophenol) have both been applied,
however there are differences amongst the two, chemically similar molecules.
Both molecules contain three nitrate groups, however picric acid contain a
hydroxyl group on carbon 1 and TNT contains a methyl group of carbon 1. Picric
acid is very difficult to detonate during humid or rainy weather conditions and
it is slightly acidic, which causes it to react with the metal container it was
stored in, which could provoke an unanticipated detonation, which would
penetrate through armor and induce unintentional casualties. TNT is also
difficult to detonate, however it is more suitable for munitions. The TNT
molecule contains a lower amount of carbon to oxygen ratio, thus the chemical
reaction may not occur completely and it is much safer to handle than
nitroglycerin because its behavior is very unpredictable. Habor, one time,
reacted nitrogen in the air with hydrogen gas to produce ammonia, which has
been used as a fertilizer and has provided many advances and improvements in
agriculture to stimulate the rate of growth of various crops; ammonium nitrate
has also been used as a fertilizer, however it has also been applied in the
warzone as mines. In order to produce the explosive compounds, nitric acid is
required. Nitric acid has been formed by reaction sulphuric acid with sodium
nitrate to form nitric acid and sodium sulphate. Ammonium nitrate is a safe
explosive when handled properly however various incidents and terroristic
attacks have occurred, involving ammonium nitrate. For example, during 1993,
terrorist have planted a bomb in the World Trade Centre in New York City . One time, in the port of Texas City , a fire has occurred.
Immediate countermeasures have been applied and the hatches have been closed
where the ammonium nitrate has been stored; however the closed hatchets
increased the pressure, compression, and heat conditions on the ship and the
load of ammonium nitrate detonated and inflicted many casualties. Explosive
molecules have changed civilization and have impacted society due to their
applications in war as weapons, however the applications of certain explosive
compounds are different today. Nitroglycerin is used to prevent heart attacks
and is used as a treatment for the pain induced by angina pectoris. As always,
profit has been generated from the trade of explosives and the demand was high,
yet the influence on society and history of certain newly synthesized and
discovered molecules does not always impart beneficial effects. What used to be
applied as an explosive to induce casualties of opponents is now used to
support the cardiovascular system and for a different purpose.





