Fluorinations in Organic Chemistry with Elemental Fluorine

Excerpt

There is a common belief that elemental fluorine, even when diluted, is a very dangerous material, extremely reactive, and hence completely unselective. We should be scared even when we only think of it! We can find many statements in the literature reflecting this sentiment: “Highly hazardous,” “use with great care,” “only for well-trained professionals,” “but fluorine – watch it,” “highly toxic,” and so on. (We don’t wish to mention the names of those scientists who otherwise are doing great chemistry, but such statements can be found in some of the most respected publications). Usually such statements come from people who never worked with diluted fluorine and in many cases as an “explanation” why they will work with other reagents frequently inferior to F₂/N₂ mixtures. It should be remembered that dilute fluorine is less dangerous and easier to work with than chlorine, for example, as if released it may spread to much shorter distances, its pressure regulators on the cylinders are more robust than those of the chlorine, and it is considerably less toxic than Cl₂, to say nothing about Br₂(!). Thus, for example, in order to feel “Irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape” the “Acute Exposure Guideline Levels (AEGL)” required for fluorine is 20 ppm for 10 min, while that for chlorine is only 2.8 ppm and for bromine it is enough to have 0.55 ppm! For that period of time [1]. …