Mustard gas: name, formula, characteristics and interesting facts about the substance
The first chemical attack in history was carried out on April 22, 1915 by German troops near the Belgian city of Ypres. As that time, chlorine was used, which became the first type of chemical weapon. The first attack was followed by a second one, on May 31 of the same year, on the Eastern Front, using phosgene. And on May 12, 1917, after several more episodes of the successful use of other toxic substances (agents), a chemical attack was again carried out near Ypres - with mustard gas, later called “mustard” at the battlefield.
Homeland mustard gas can be considered Belgium. Her native, physicist Cesar Depre, for the first time in 1822 synthesized this substance. He received mustard gas when exposed to ethylene sulfur chloride (sulfur dichloride). Mustard gas was also obtained by Rich in 1854 and by Frederick Guthrie in 1860 using the same reagents.The latter in his research has already spoken about the damaging effects of gas.
For the first time pure mustard gas was obtained by the German scientist Victor Meyer. Instead of direct synthesis, he used thiodiglycol and phosphorus trichloride. Meyer described in detail the physical and chemical properties of this compound.
During the First World War and after it, Lommel and Steinkopf studied gas (then the original name of this substance, Lost, appeared). Thanks to their research, Germany was able to apply Lost as early as 1917. The method of preparation was the same as that of Meyer, only thionyl chloride was used instead of carbon trichloride.
After the gas attacks, the Entente countries realized the effectiveness of mustard gas and after a while also started its production.
In Guiller's Germany, the production of mustard gas was of great importance: the volume of OM produced was measured in hundreds of thousands of tons. Its destruction after the war took about ten years.
Value and benefits
Before the mustard gas, the Germans used poisonous chlorine and asphyxiating phosgene / diphosgene (and also their mixtures in different proportions) - gaseous OM.For all their effectiveness, they also had disadvantages: dependence on meteorological conditions, difficulties with the delivery and installation of gas cylinders, poorly controlled damage radius. With the invention of artillery firing ammunition with agents, it became possible to use toxic substances in any aggregative state: liquid, solid, gaseous. Solid compounds with arsenic have been used here. However, the Entente countries quickly improved gas masks, and these agents became ineffective.
With the advent of mustard, a new stage in the development of organic matter began. The main feature of the Lost gas was a skin-blistering action - in addition to the respiratory organs, it also affected the eyes and body areas, penetrating under clothes and shoes, but did not save gas masks. In addition, mustard gas had a low volatility - it allowed to "infect" not the living force, but entire sections of the terrain.
Due to this number of advantages over other first-generation chemical agents, mustard gas remained "in service" for a long time, its production in large volumes took place until the middle of the 20th century.
The systematic name of mustard is 2,2'-dichlorodiethylsulfide.In England and the United States, it is called "mustard gas" for its characteristic caustic garlic odor. In Germany, the gas was given the code names H (for technical), HS and later HD for distilled substance.
The formula of mustard gas is relatively uncomplicated.
Under normal conditions (atmospheric pressure, temperature 20oC) mustard gas - volatile oily liquid. The characteristic smell and yellowish color give impurities. It does not dissolve in water, but hydrolyzes (decomposes) to form thiodiglycol. It is limited in alcohol, and in organic solvents - ether, benzene, chloroform, animal and vegetable oils - very well. It is also highly soluble in other chemical agents, which allows you to create mixtures of several substances.
Chemical properties and neutralization
Although earlier in the article it was mentioned that poisonous mustard gas undergoes hydrolysis in water, in practice the following was often observed: mustard gas stored for several years in adverse conditions, in wet rooms or in damaged cylinders, lost little of its activity. This does not correspond to laboratory data: if a substance is hydrolyzed, it ceases to exist in its original molecular (for gas) form and loses its properties.This contradiction is explained by the fact that water and mustard gas are non-miscible liquids: intensive mixing occurs in the laboratory during hydrolysis, and the reaction goes through the whole volume, and in field conditions the water covers the mustard gas with a layer, and the reaction takes place only at the interface of two media, yes and that is extremely slow and reversible.
For degassing (neutralization) of mustard in large volumes of bleach, in common "bleach" is of particular importance. Apply it in the form of a concentrated aqueous solution in which infected objects are soaked in, thoroughly mixed. Hypochlorites are the most economically beneficial: they are inexpensive and are produced in large quantities.
In recent decades, chloramines have become important for degassing poisonous mustard gas. Chloramine T is one of the most important in practical application. Compared with the complex effect of bleach on mustard gas, the reaction with the sodium salt of chloramine T is simple: sulfur in dichlorodiethyl sulfide is oxidized, and the product of addition of chloroamine to it is formed. On the basis of chloramine T in the USA, a mixture was created that is suitable for degassing even instruments and cars.
The remaining degassing mixtures, although they may be more efficient, have only limited application in practice due to the high cost of raw materials and the complexity of production.
One of the qualitative reactions, which makes it possible to detect 10 mg of mustard gas in 1000 liters of air, is the reaction with gold (II) chloride, characterized by the appearance of a yellowish precipitate in chloride solution, and at high concentrations of mustard gas, reddish-yellow oily droplets.
There are three main ways to obtain mustard gas in the laboratory and on an industrial scale.
The first is the reaction of ethylene with sulfur dichloride. This method was developed by Guthrie.
The second method was discovered by Meyer and consisted in the action on thiodiglycol by chlorinating agents: phosphorus chlorides, hydrochloride, thionyl chloride.
The third method was developed in 1942 by Lazier in the USA. It is based on the interaction of hydrogen sulfide with vinyl chloride in the presence of organic peroxides as catalysts. The yield of the product can reach 75% - this is a high figure for organic synthesis.
Action on the body
Mustard gas is a poisonous and blistering poisoning agent.It acts on all parts of the body, therefore, to protect against it requires special clothing, covering the entire surface of the body.
Mustard must have a latent period of action, that is, immediately after contact with the skin, there will be no symptoms, and only after 2-6 hours the redness appears, inflammation - the epidermis is rejected. The epidermis dies off, and suppuration and ulcers appear in its place, requiring prolonged treatment. If there is no such treatment, death occurs between several hours and one month (depending on the dose of agents).
When mustard gas comes into contact with the eyes, inflammation of the anterior part of the eye, especially of the cornea, begins (even loss of vision is possible due to clouding). Next, purulent conjunctivitis and tissue necrosis develop, which requires long-term treatment.
The effect of mustard on the respiratory system is localized in the upper respiratory system. Internal bleeding appears, purulent and gangrenous foci appear, and at high concentrations pulmonary edema can develop.
The general poisoning effect of mustard gas is due to the fact that it not only interacts with the affected areas,but also absorbed into the bloodstream and spread throughout the body, which is manifested in impaired circulation, toxic renal, gastrointestinal and cerebral hemorrhages.
It is known that before the Second World War and during it, the military chemical laboratories in the USA and England were engaged in Levinstein yperite, a mixture of ordinary mustard gas with polysulfides, which contained long chains of sulfur atoms. It is difficult to judge the military significance of this substance.
After the First World War, the already mentioned Steinkopf obtained dibromo- and diiodo-diethylsulfides (the so-called bromine-Lost and iodine-Lost). They did not receive widespread use, since they correspond to conventional mustard gas in terms of efficiency, and are much more expensive in production.