Methyl nitrate is the methyl
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
of
nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...
and has the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
CH
3NO
3. It is a colourless explosive volatile liquid.
Synthesis
It can be produced by the
condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to ...
of
nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...
and
methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...
:
:CH
3OH + HNO
3 → CH
3NO
3 + H
2O
A newer method uses
methyl iodide and
silver nitrate
Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar caustic' ...
:
CH
3I + AgNO
3 → CH
3NO
3 + AgI
Methyl nitrate can be produced on a laboratory or industrial scale either through the
distillation
Distillation, or classical distillation, is the process of separation process, separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distilla ...
of a mixture of methanol and nitric acid, or by the
nitration
In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters between alcohols and ...
of methanol by a mixture of
sulfuric and nitric acids. The first procedure is not preferred due to the great explosion danger presented by the methyl nitrate
vapour
In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Herr ...
. The second procedure is essentially identical to that of making
nitroglycerin. However, the process is usually run at a slightly higher temperature and the mixture is stirred mechanically on an industrial scale instead of with compressed air.
Explosive properties
Methyl nitrate is a sensitive
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...
. When ignited it burns extremely fiercely with a gray-blue flame. Methyl nitrate is a very strong explosive, like
nitroglycerin,
ethylene glycol dinitrate
Ethylene glycol dinitrate, abbreviated EGDN and NGC, also known as Nitroglycol, is a colorless, oily, explosive liquid obtained by nitration, nitrating ethylene glycol. It is similar to nitroglycerine in both manufacture and properties, though it ...
, and other
nitrate ester
In organic chemistry, a nitrate ester is an organic functional group with the formula , where R stands for any organic residue. They are the esters of nitric acid and alcohols. A well-known example is nitroglycerin, which is not a ''nitro'' co ...
s. The sensitivity of methyl nitrate to initiation by
detonation
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with ...
is among the greatest known, with even a number one
blasting cap
A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common.
The commercial use of explosives uses electri ...
, the lowest power available, producing a near full detonation of the explosive.
Despite the superior explosive properties of methyl nitrate, it has not received application as an explosive due mostly to its high
volatility, which prevents it from being stored or handled safely.
Safety
As well as being an explosive, methyl nitrate is
toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
and causes headaches when inhaled.
History
Methyl nitrate has not received much attention as an explosive, but as a mixture containing 25% methanol it was used as rocket fuel and volumetric explosive under the name Myrol in
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. This mixture would
evaporate
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...
at a constant rate and so its composition would not change over time. It presents a slight explosive danger (it is somewhat difficult to detonate) and does not detonate easily via shock.
According to A. Stettbacher, the substance was used as a combustible during the
Reichstag fire in 1933. Gartz shows in a recent work that only methyl nitrate with its production and explosion potential can represent the famous and mysterious "shooting water" from the German ''Feuerwerkbuch'' ("fireworks book") of about 1420 (the oldest technical text in
German language
German ( ) is a West Germanic languages, West Germanic language mainly spoken in Central Europe. It is the most widely spoken and Official language, official or co-official language in Germany, Austria, Switzerland, Liechtenstein, and the Ita ...
, handwritten in
Dresden
Dresden (, ; Upper Saxon: ''Dräsdn''; wen, label=Upper Sorbian, Drježdźany) is the capital city of the German state of Saxony and its second most populous city, after Leipzig. It is the 12th most populous city of Germany, the fourth larg ...
and later printed in
Augsburg
Augsburg (; bar , Augschburg , links=https://en.wikipedia.org/wiki/Swabian_German , label=Swabian German, , ) is a city in Swabia, Bavaria, Germany, around west of Bavarian capital Munich. It is a university town and regional seat of the ' ...
).
An extract of the text from the 1420 ''Feuerwerkbuch'' is as follows (written in
Early New High German
Early New High German (ENHG) is a term for the period in the history of the German language generally defined, following Wilhelm Scherer, as the period 1350 to 1650.
The term is the standard translation of the German (Fnhd., Frnhd.), introduce ...
):
Translated:
Structure
The structure of methyl nitrate has been studied experimentally in the gas phase (combined
gas-electron diffraction and
microwave spectroscopy
Microwave spectroscopy is the spectroscopy method that employs microwaves, i.e. electromagnetic radiation at GHz frequencies, for the study of matter.
History
The ammonia molecule NH3 is shaped like a pyramid 0.38 Å in height, with an equilatera ...
, GED/MW) and in the crystalline state (
X-ray diffraction, XRD) (see Table 1).
In the solid state there are weak interactions between the O and N atoms of different molecules (see figure).
References
External links
*{{cite web , url=https://webbook.nist.gov/cgi/cbook.cgi?ID=C598583 , title=Methyl nitrate , work=Webbook , publisher=NIST
Alkyl nitrates
Explosive chemicals
Liquid explosives
Methyl esters