Molecules that changed the world – Mustard Gas
Mustard gas (sulfur mustard) has a melting point of 218˚C and is therefore a liquid at room temperature. It is colourless when pure although can be seen to be yellow/brown when impure, it is very toxic . The first recorded synthesis of mustard gas was in 1822 by a French chemist, César-Mansuète Despretz who synthesised it by the following reaction:
Above, bis (2-chloroethyl) sulfide (Mustard gas) is produced from the electrophilic addition of sulfur dichloride to ethane. Its properties were first defined by Fredrick Gurthie who in his paper ‘on some derivatives of olefines’ as “smelling like mustard, tasting like garlic, and causing blisters after contact with the skin”. Historically, mustard Gas had found no significant use until World War I where interest spread in the development of new chemical weapons . Wilhelm Steinkopf, a German chemist; working under the invitation of Fritz Haber, was responsible for developing a large scale method of mustard gas production . He did this using a process developed by an English chemist; Hans Thatcher Clarke, from the Mayer method, where ethanol is reacted with hypochlorous acid and then sodium sulfide. The product of which is heated with Hydrochloric acid . This method proved most useful to the german army as it used 2-chloroethanol, which was readily available due to its large scale use in the chemical dye industry . In 1916 Steinkopf had developed a process and in 1917 mustard gas it found its first use in Ypres, Belgium against the British and Canadian forces as a chemical weapon . Steinkopf discontinued development later that year as his work had affected his own health . The German army continued using mustard gas again in Ypres, against the French army. It took a year before the British had developed their own large scale Process for mustard gas manufacture which was largely based on the Despretz method . Mustard made an effective chemical warfare agent because it’s lethality is low compared to other warfare agents causing more injury (80% of chemical warfare casualties in WWI) and further difficulty for logistical and medical parts of the military and unlike other warfare agents mustard gas couldn’t be evaded by wearing a gas mask. Mustard gas has changed the world because of the adverse way it has affected its casualties. After exposure it will cause blistering and up to second degree burns, furthermore it has carcinogenic and mutagenic affects in the long term; caused by the alkylation of base compounds in DNA, causing it to break eventually inhibiting enzymes in the body . The main cause of death from mustard gas was where it was inhaled and the vesicant effects on the respiratory system . Sulfur mustard considered that its use a...