Educator Indian Journal of Chemical Technology Vol. 9. July 2002. pp. 363-372 The History of Fluorine-From discovery to commodity Jaime Wisniak* Department of Chemical Engineering. Ben-Gurian University of the Negev. Beer-Sheva. Israel 84105 Fluorine was the last of the halogens to be isolated. The extreme difficulties and dangers of handling it retarded substantial commercial applications until World War II when it became essential for the development of nuclear devices. Development of industrial processes for the manufacture of hydrogen Duoride and chloroDuorinated hydrocarbons turned Duorine and its derivatives into a major chemical commodity. The end use pattern of Duorine has reDected the changes in social appreciation of environmental protection and safety. Discovery offluorine An interesting aspect of the history of fluorine is The first historical reference regarding the use of that Andre-Marie Ampere (1775-1831) coined its fluorine compounds seems to be in the books of name before it was isolated. Ampere's interest in George Agricola (1494-1555), particularly in De Re chemistry led him to deduce that hydrogen fluoride l Metallica • When describing the manufacturing of was analogous to hydrogen chloride. He believed that metals, particularly iron, he wrote: Finally there now "silicated fluoric acid"(hydrofluoric acid) contained a remains those stones which I call stones which easiLy peculiar principle, analogous to chlorine and oxygen, meLt in the fire, because when thrown into hot united to the basis or silica, or silicum; the fluoboric furnaces they flow. According to Hoover and Hooverl acid of the same principle united to boron; and the there is little doubt that some of these stones included pure liquid fluoric acid as this principle united to fluorspar. Agricola derived the names fluorine and hydrogen. During the Napoleonic wars with England fluorspar from the Latinfluere meaning flow or flux. Ampere succeeded in sending two letters to Humphry The systematic study of fluorine chemistry began in Davy (1778-1819) in which he exposed his ideas 5 1764 when Andreas Sigmund Marggraff (1709-1782) regarding fluorine . The first letter contained a attempted to determine the composition of fluorspar suggestion that the unknown substance combined by heating a mixture of it with sulphuric acid in a with hydrogen in hydrogen fluoride might be glass retort. He found a white saline sublimate separated by electrolysis of the anhydrous acid using suspended in the water of the receiver and concluded a carbon anode: it rests to know if electricity will that sulphuric acid separates a volatile earth from decompose hydrogen fluoride in the liquid state, after fluorspar. In addition, he remarked that the retort was most the water has been eliminated, delivering corroded into hoLes in several placei. In 1771, Carl hydrogen on one side and hydrofluoric acid on the Wilhelm Scheele (1742-1786) repeated Marggraffs other. experiment and concluded that sulphuric acid In his second letter Ampere changed the name of liberated a peculiar acid, which was combined with the element from term oxy-fluorique to fluorine, to lime in fluorspar; he also noted that the distillation harmonize it with the then recently adopted name flask was heavily corroded. The acid was called chlorine. Shortly thereafter, Ampere abandoned the flussaiire and fluorspar was designated flussaurer term le fluore in favour of le phtore (from the Greek kalk. Scheele also observed that heating caused phtoros, destructive): I have selected the name phtore fluorspar to lose its property of fluorescence, without from the Greek adjective ¢tJopWS (also ¢tJoPOS, change in weight. Scheele was perplexed by the that is simultaneously a noun and an adjective), deposit of silica obtained in the receiver and thought meaning to delete, that has the force to ruin, to 5 that flussalire had the property of forming silica when destroy, to corrupt . 3 in contact with water .4. After Scheele's preparation of impure hydrogen fluoride in 1771, it fell on Davy to recognize the *For correspondence: (E-mail: [email protected]) presence of a new element in the compound. In a Educator Indian J. Chern. Techno!.. July 2002 paper presented to the Royal Society of London he through heating fluorspar with boric oxide in an iron 6 wrote : It appears reasonable to conclude that there tube. exists in the fluorine compounds a peculiar substance. Louyet experimented on the possibility of isolating possessed of strong interaction for metallic bodies and putting in evidence Ie radical de l'acide and hydrogen and which combined with certain fluorhydrique by heating sheets of transparent inflammable bodies forms a peculiar acid. which. in fluorspar in a vase made of fluorspar. He found that consequence of its strong affinities and high fluorine was a colourless gas that did not bleach decomposition agencies. it will be very difficult to vegetable colours, decomposed water without the examine in a pure form. and for the sake of avoiding assistance of light, attacked glass, and acted on all circumlocutioll it may be denominated fluorine. a metals except gold and platinum (except when in the 6 Ilam.e suggested to me by A. Ampere . nascent state). In addition, while other silver halides were insoluble when anhydrous and did not Davy tried to electrolyse hydrogen fluoride (which decompose on heating, silver fluoride was he called fluoric acid and its salts fluates) without deliquescent, decomposed on heating, and was success, because his material contained an appreciable impossible to dehydrate it completely. Similarly, amount of water and thus no fluorine was formed. He calcium halides were deliquescent, while calcium did, however, observe that the electrical resistivity of 8 fluoride was insoluble in water . the electrolyte increased considerably as the water Louyet also determined the equivalent (atomic) content decreased. He attempted to overcome this weight of fluorine as 239.81 (based on oxygen as 1.0) difficulty by trying to decompose the acid by passing in comparison with the value of 233.801 that had been electrical sparks produced by the "great Voltaic determined by Berzelius. He was unable to explain batteries. of the Royal Institution", but could not the difference. examine the results properly because the "sulTounding atmosphere became filled with the fumes of fluoric He ended hi s memoir with a warning regarding the acid." He remarked th at as a result of the fumes hi s problems of experimenting with fluorine and fingers became sore under the nails, producing a most hydrogen fluoride and emphasizing the need to take 6 extreme safety precautions: In relation to the nature painful sensation in hi s eyes that lasted for hours . offluorine. I must remark that if there are still doubts Davy also noticed that liquid fluoric acid about it. these are due to the imperfections of the immediately destroyed glass and all animal and equipment we have been forced to use. It is necessary vegetable substances and acted on all bodies to take extreme precautions to avoid the action of containing metallic oxides. He remarked that he did hydrogen fluoride vapours because they seriously not know of any other substances that are not rapidly affect the human body. All the chemists that have di ssolved or decomposed by fluoric acid, except dealt witlzfluorine have suffered its dangerous effects. metals, charcoal, phosphorus, sulphur, and certain Gay Lussac and Thenard have strongly insisted about combinations of chlorine. He found that the specific its dangerous effects; among them. acute pain under gravity of the acid was 1.0609 when distilled in a pure th e nails. temporary eye inflammation. eye fatigue. silver alembic and that it increased to 1.25 when chest pain. prolonged pharynx irritation. heavy di ssolved in water. He also estimated that the atomic spitting. many times bloody. all of these symptoms weight of fluorine was less than one-half that of requiring a long time for their recovery. Very seldom chlorine (the actual ratio is 0.535). these effects are of short duration. Th. Knox felt that Joseph-Louis Gay-Lussac (1778-1850) and Louis­ he was about to die, the effects disappeared only (ifter Jacques Thenard (1777-1857) reported? that they had using hydrogen cyanide for six months. His brother prepared concentrated hydrogen fluoride by heating a George J. Knox felt the effects of fluorine for more mixture of virtually silica-free white fluorspar with than three years and had to move to Naples to concentrated sulphuric acid in a lead apparatus and recover. Regarding myself, my health has been condensing the vapours at O°c. Their product fumed affected seriously and I have spit blood in several 8 strongly in air, dissolved glass easily and fast, opportunities . Louyet passed away a short time after possessed a great affinity for water, and caused writing these words. painful burns on contact with the skin. Gay-Lussac Domange described the difficulties related to the and Thenard elucidated the action of hydrogen isolation of fluorine as follows: It is very clear that fluoride on silica and also discovered boron trifluoride the isolation of fluorine could not be the result of a 364 Wisniak: History of Fluorine Educator well-reasoned experiment. At that time the properties Henri Moissan (1852-1907; 1906 Nobel Prize for of fluorine were unknown. Hydrogen fluoride is very Chemistry) is usually considered the first to isolate dangerous and hard to manipulate in the anhydrous fluorine and the first to develop a method capable of state, barring any possibility of obtaining fluorine as preparing the gas in appreciable quantity II. However, 9 the result of a chance experiment. This same chance as pointed out by Domange , it appears certain that had, in the past, allowed the discovery of other Fremy was successful in producing a small amount of 9 elements . fluorine some 30 years before Moissan.