Different than other ring structures; Alternating double bond or delocalized electrons.

Unsaturated Hydrocarbons

Involved in chemical signals in insects such as pheromones; also in some nail polish removers

Much higher boiling point than alkanes but lower than carboxylic acids; can H-bond; can be found in beer and wine.

Synthetic ones used to flavour processed foods and as scents in cosmetics and perfumes.

Unpleasant odour such as rotting fish and animal flesh from the breakdown of proteins.

Shorter chain examples have a strong unpleasant odour; Gives bitter almond and vanilla its essence.

Used in fridges and air conditioner, non-stick coating, DDT and PCBs

Used in anesthetics and as a solvent for fats and oils; volatile and highly flammable.