Why are functional groups important?
Functional groups are the backbone of Organic Chemistry. It is the functional groups that a molecule contains which dictate how the molecule works both chemically and biologically and determines the physical properties of the molecule. For example the boiling point, density, solubility and ionisation energy, to name but a few are all dependent on the properties of the functional group. Also functional groups allow us to spot trends between molecules, since molecules containing the same group have similar chemistry. This allows us to predict how large and complex molecules will react by just knowing about the reactivity of the functional group in its simplest form. Functional groups are especially useful in identifying molecules, for instance using Infra-Red Spectroscopy the different group frequencies are distinguished using correlation charts.
There are many types of functional groups each showing different characteristic behaviour and affinity for different types of compounds. A grouping of molecules containing an identical functional group is called a homologous series. Each separate series is identified by either a prefix or suffix which is included in the name of the molecule. Some of the most commonly known functional groups are listed below with more information.