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 a ...

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 symbol ...

CH₃NO₃. It is a colourless explosive volatile liquid.

Synthesis

It can be produced by the condensation of

and methanol: :CH₃OH + HNO₃ → CH₃NO₃ + H₂O 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 causti ...

: CH₃I + AgNO₃ → CH₃NO₃ + AgI Methyl nitrate can be produced on a laboratory or industrial scale either through the

distillation Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the heat ...

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 an ...

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. 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 nitrating ethylene glycol. It is similar to nitroglycerine in both manufacture and properties, though it is more v ...

, 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'' com ...

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 s ...

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 subs ...

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 opposing ...

. This mixture would evaporate 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 language mainly spoken in Central Europe. It is the most widely spoken and official or co-official language in Germany, Austria, Switzerland, Liechtenstein, and the Italian province of South Tyrol. It is als ...

, 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 ...

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): 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). Methylnitrat

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