This chemical drawing example shows structural formulas of organic molecules - polycyclic aromatic hydrocarbons (PAHs), also known as poly-aromatic hydrocarbons or polynuclear aromatic hydrocarbons: naphthalene, anthracene, triphenylene, acenaphthylene, phenanthrene, pyrene.
"Polycyclic aromatic hydrocarbons (PAHs), also known as poly-aromatic hydrocarbons or polynuclear aromatic hydrocarbons, are fused aromatic rings and do not contain heteroatoms or carry substituents. Naphthalene is the simplest example of a PAH. PAHs occur in oil, coal, and tar deposits, and are produced as byproducts of fuel burning (whether fossil fuel or biomass).
They are potent atmospheric pollutants. Some compounds have been identified as carcinogenic, mutagenic, and teratogenic. PAHs are also found in cooked foods. Studies have shown that high levels of PAHs are found, for example, in meat cooked at high temperatures such as grilling or barbecuing, and in smoked fish.
They are also found in the interstellar medium, in comets, and in meteorites and are a candidate molecule to act as a basis for the earliest forms of life." [Polycyclic aromatic hydrocarbon. Wikipedia]
The chemical drawing example "PAH compounds" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Chemistry solution from the Science and Education area of ConceptDraw Solution Park.