Fantastic Fluorine

By Michael Edmonds 16/06/2013

The recent debate in Hamilton over fluoridation of the water supply has resulted in a lot of misinformation about fluorine and fluoride. Elsewhere, however, fluorine is playing an important role the development of new pharmaceuticals.

However, before I get on to discussing the use of fluorine in pharmaceuticals, let’s clarify a few points, particularly about the different between fluorine and fluoride.

Fluorine, is both an element and a molecule. As an element (F) it is the smallest of the highly reactive halogen group on the periodic table. This reactivity means that it cannot readily exist as the element. It can however exist as the gas F2, where two fluorine atoms have joined together to stabilise each other. Fluorine gas (F2) is a toxic and corrosive gas.

Fluorine can also form a stable compound with metals, for example, NaF (sodium fluoride). Such compounds are referred to as ionic compounds/salts, where the fluorine atom has gained a negative charge, existing as F (fluoride). In this form it has very different properties to F2, for example, it is a solid rather than a liquid, is able to strengthen tooth enamel, and is far less toxic than F2.

Fluorine can also be attached to carbon atoms in organic molecules, including drugs, to produce new molecules with interesting properties. The carbon-fluorine bond tends to be very strong, and is able to introduce some new properties to drugs. For example, it can increase their fat solubility (allowing them to better cross cell membranes). It can also alter the 3-D shape of a drug, allowing it to better bind to receptors in the body.

At a recent medicinal conference in April, the structures of five new drugs were revealed – three of which contain fluorine. Over the past decade there has been an increase in the number of drugs containing fluorine, as chemists have become more adept at fluorine chemist.

The new drugs include:

BMS-906024, developed for the treatment of breast, lung and colon cancer, as well as leukaemia. See here for more information.


LGX818, developed for the treatment of melanoma. See here for more information.




AZD5423, developed for the treatment of chronic obstructive pulmonary disease. See here for more information.






0 Responses to “Fantastic Fluorine”

  • Hi Michael. You say, “Fluorine, is both an element and a compound.”

    Are you sure?

    Further down you are correct when you say, “Fluorine can also form a stable compound with metals, for example, NaF (sodium fluoride). ”

    A compound consists of two or more different chemical elements. There are some exceptions, but pure chemical elements such as H2 or F2 are not considered chemical compounds.

    • Well spotted RonL, that should have (and now does) read “Fluorine is both an element and a molecule.”

  • Oops, previous post sent too soon. Meant to say that not all fluorine-containing compounds are called fluorides. Personally, I’d say fluorine is an element and a component of compounds, but organofluorine is more accurate than organofluoride.

  • Bruce,
    Yes, just to clarify we can talk about fluorine as the element or the molecule.
    Fluorides commonly refer to salts containing fluorine such as NaF (sodium fluoride).
    Organic compounds containing fluorine are typically referred to as organofluorine compounds.