organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...

, a nitrate ester is an organic

functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...

with the formula , where R stands for any

organic residue Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have c ...

. They are the

esters 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 are ...

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

alcohols In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. The term ''alcohol'' originally referred to the primary alcohol ethanol (ethyl alcohol), which is ...

. A well-known example is nitroglycerin, which is not a ''nitro'' compound, despite its name. :

Synthesis and reactions

Nitrate esters are typically prepared by condensation of nitric acid and the alcohol: For example, the simplest nitrate ester,

methyl nitrate Methyl nitrate is the methyl ester of nitric acid and has the chemical formula CH3NO3. It is a colourless explosive volatile liquid. Synthesis It can be produced by the condensation of nitric acid and methanol: :CH3OH + HNO3 → CH3NO3 + H2O A ...

, is formed by reaction of

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 ...

and

in the presence of sulfuric acid: :CH3OH + HNO3 -> CH3ONO2 + H2O This condensation is sometimes called "nitroxylation".

Explosive properties

The thermal decomposition of nitrate esters mainly yields the gases molecular

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

(N₂) and carbon dioxide. The considerable chemical energy of the detonation is due to the high strength of the bond in molecular nitrogen. This stoichiometry is illustrated by the equation for the detonation of nitroglycerin. : Nitroglycerine Destruction V

Illustrative of the highly sensitive nature of some organic nitrates is Si(CH₂ONO₂)₄.''Sila-Explosives Offer A Better Bang'' Stephen K. Ritter

Chemical & Engineering News ''Chemical & Engineering News'' (''C&EN'') is a weekly news magazine published by the American Chemical Society, providing professional and technical news and analysis in the fields of chemistry and chemical engineering.Link
/ref> A single crystal of this compound detonates even upon contact with a

teflon Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemou ...

spatula and in fact made full characterization impossible. Another contributor to its exothermic decomposition (inferred from much safer

in silico In biology and other experimental sciences, an ''in silico'' experiment is one performed on computer or via computer simulation. The phrase is pseudo-Latin for 'in silicon' (correct la, in silicio), referring to silicon in computer chips. It ...

experimentation) is the ability of silicon in its crystal phase to coordinate to two oxygen nitrito groups in addition to regular coordination to the four carbon atoms. This additional coordination would make formation of

silicon dioxide Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

(one of the decomposition products) more facile.

Medical use

The nitrate esters

isosorbide dinitrate Isosorbide dinitrate is a medication used for heart failure, esophageal spasms, and to treat and prevent chest pain from not enough blood flow to the heart. It has been found to be particularly useful in heart failure due to systolic dysfunction ...

(Isordil) and

isosorbide mononitrate Isosorbide mononitrate, sold under many brand names, is a medication used for heart-related chest pain (angina), heart failure and esophageal spasms. It can be used both to treat and to prevent heart-related chest pain; however, it is generally ...

(Imdur, Ismo, Monoket, Mononitron) are converted in the body to

nitric oxide Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its che ...

, a potent natural vasodilator. In

medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

, these esters are used as a medicine for

angina pectoris Angina, also known as angina pectoris, is chest pain or pressure, usually caused by insufficient blood flow to the heart muscle (myocardium). It is most commonly a symptom of coronary artery disease. Angina is typically the result of obstru ...

( ischemic heart disease).

Related compounds

Acetyl nitrate Acetyl nitrate is the organic compound with the formula CH3C(O)ONO2. It is classified as the mixed anhydride of nitric and acetic acids. It is a colorless explosive liquid that fumes in moist air. Synthesis and reactions It is prepared from ace ...

is a nitrate anhydride, being derived from the condensation of nitric and acetic acids.

References

{{Authority control Functional groups *