Element of the Week – Fluorine

By Michael Edmonds 26/01/2014

Fluorine is a fascinating element. As a gas consisting of two fluorine atoms bonded to each other it is incredibly reactive, capable of eating into glass and igniting some substances. However, organic compounds (compounds containing carbon) containing fluorine can be incredibly stable, as the carbon fluorine bond is relatively strong.

Fluorine is a very small atom compared to most of the other elements on the periodic table, and this combined with it’s strong bonds can significantly change the properties of molecules which contain fluorine. Some of my research 5 to 10 years ago involved incorporating a single fluorine atom into biologically active molecules to explore the change in properties. For example, a single fluorine atom can either help or disrupt structures such as helices in biological molecules.

A well known organofluorine molecule (an organic molecule containing one or more fluorine atoms) is Teflon. This highly stable polymer is used to provide nonstick surfaces on fry pans as well as strong, water and chemical resistant materials such as Gore Tex.

Substances used to fluoridate water supplies contain fluorine atoms, but they are not present as the highly reactive gas, I described earlier. Instead they are present as fluorine ions, fluorine atoms which have gained an extra electron which make them far less reactive. The substances used to fluoridate water are added to give a concentration of around 0.7 ppm, a very low concentration but one shown to have a positive effect on dental health.

Fluorine is truly a fascinating element, with many applications.