Benzene. Molecular model of the aromatic hydrocarbon benzene (C6.H6), shown as a 3D ball-and-stick model with wireframes. This natural constituent of crude oil is used as a precursor to the production of more complex chemicals. The study of the aromatic ring structure of benzene was crucial to the success of organic chemistry. Atoms are represented as spheres and are colour-coded: carbon (grey) and hydrogen (white).