Nitrotriazolone (NTO) is a

heterocyclic A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo ...

high 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 exp ...

first identified in 1905, but research into its explosive properties was not conducted until the 1980s. NTO is currently being used by the

US Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

in munitions, specifically

Insensitive munitions Insensitive munitions are munitions that are designed to withstand stimuli representative of severe but credible accidents. The current range of stimuli are shock (from bullets, fragments and shaped charge jets), heat (from fires or adjacent ther ...

replacing those made with legacy explosives. Nitrotriazolone is being progressively made use of in novel explosive formulations, such as

IMX-101 IMX-101 is a high-performance insensitive high explosive composite mixture developed by BAE Systems and the United States Army to replace TNT in artillery shells, starting as soon as 2011. IMX stands for "Insensitive Munitions eXplosives", which ...

, a new, safer alternative to

TNT Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagen ...

specially devised in 2010 by

BAE Systems BAE Systems plc (BAE) is a British multinational arms, security, and aerospace company based in London, England. It is the largest defence contractor in Europe, and ranked the seventh-largest in the world based on applicable 2021 revenues. ...

, where it is combined with 2,4-Dinitroanisole and

Nitroguanidine Nitroguanidine - sometimes abbreviated NGu - is a colorless, crystalline solid that melts at 257 °C and decomposes at 254 °C. Nitroguanidine is an extremely insensitive but powerful high explosive. Wetting it with > 20 wt.-% water effe ...

. As such, NTO is found in the vast majority of IMX formulations. The

Picatinny Arsenal The Picatinny Arsenal ( or ) is an American military research and manufacturing facility located on of land in Jefferson and Rockaway Township in Morris County, New Jersey, United States, encompassing Picatinny Lake and Lake Denmark. The Ars ...

has also adopted the implementation of NTO and DNAN in many of their likewise newly developed insensitive explosive mixtures, which share many of the same applications of the IMXs.

Properties

Nitrotriazolone shows keto–enol

tautomerism Tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hyd ...

through proton transfer reactions. The keto form shows significantly different stability to heat, friction, and impact. Nitrotriazolone can form either mono or a di hydrate.

Preparation

NTO was first made in 1905 in a two step process.

Semicarbazide Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea. Synthesis The compound prepared by treating urea with hydrazine:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazi ...

hydrochloride is condensed with

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Es ...

to produce 1,2,4-triazol-3-one, which is nitrated with

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 ...

to form nitrotriazolone.

Toxicity

In vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...

'' studies showed the nitrotriazolone is absorbed through the skin and

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

. In the

kidneys The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...

, NTO is broken down into 5-amino-1,2,4-triazol-3-one, which undergoes oxidative denitrification and forms urazoles and

nitrites The nitrite ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite also re ...

in rats.

References

Explosive chemicals Nitro compounds {{explosive-stub