Aromatic

Aromatic means fragrant but is also used in the context of aromatic compounds in chemistry. An aromatic compound is then an organic compound in which there is a conjugated system of π-bonds in which 4n+2 electrons are delocalised. When not two, but four electrons are shared between two atoms, thus providing the chemical bond (a so-called double bond, two of those electrons are located between the atoms, and the other two are located in a plane adjacent to the bond. The latter two are called π-electrons. These π-electrons are not only between the atoms they bind, but also a little bit next to them. When two double bonds in a structure are separated by a single bond, the π-electrons of the two double bonds lie in the same plane, and the π-electrons can come from one double bond to the other. Such systems are called conjugated, and the electrons that can move through the molecule are called delocalised. When a conjugated system contains 4n+2 electrons (6 or 10 or 14 etc.), this provides a very large extra stability to the molecule. A molecule with such a system is called aromatic.