Conjugated system

This delocalisation creates a region where electrons are not belonging to a single bond or atom, but rather a group. An example would be phenol (C₆H₅OH, benzene with hydroxyl group) (which does not contain double bonds, but diagramatically has alternating single and double bonds) which has a system of 6 electrons above and below the flat planar ring, as well as around the hydroxyl group.

Conjugated systems often have unique properties, such as beta caroteens long conjugated hydrocarbon chain resulting in its strong colour. This is because photons of lower energies can exite the bonds with slightly lower activation enthalpy, allowing photons in the visible region of the spectrum to be absorbed.

Conjugated systems are often present in chromophores[?], found in polymers which are coloured or glow in the dark. They are usually caused by conjugated ring systems with bonds such as C (Double Bond) O and N (Double/Triple Bond) N.