Ring ring! Naphthalene calling

What does it look like?

Three views of the Naphthalene molecule. From left to right are the molecule itself, then two direction in the high-pressure crystal structure. Image generated by the Mercury crystal structure visualisation software http://www.ccdc.cam.ac.uk/Solutions/CSDSystem/Pages/Mercury.aspx

Naphthalene has the chemical formula C₁₀H₈, and consists of two benzene molecules joined along one edge. This makes it the simplest of the polyaromatic hydrocarbons (PAHs), a class of molecules made up of multiple fused aromatic carbon rings.

What is it?

Naphthalene is derived from fossil fuels, specifically coal tar, which naturally contains up to 10% naphthalene. It is a white solid with a strong, characteristic odour and sublimes readily. Historically, naphthalene found a use around the home in mothballs, but has now been largely replaced by other molecules like camphor and dichlorobenzene. Naphthalene is an important precursor compound for the production of many synthetic chemicals and in a number of industrial processes. The most significant modern use of naphthalene is in the synthesis of phthalic anhydride and naphthalene sulfonic acids. These molecules are important in the production of plastics, rubbers, pesticides and building materials.

Where did the structure come from?

Naphthalene was among the first organic molecules to be studied with crystallography, with W. H. Bragg undertaking the first studies in the 1920s. Dual Nobel Prize-winner Linus Pauling et al., predicted in 1935 that despite the high degree of electron delocalisation within the molecule, the lengths of the bonds between all carbon atoms would not be equivalent. In 1949, crystallographic data obtained by Abrahams et al. confirmed Pauling's predictions.

The structure we've actually featured is a high-pressure form of Naphthalene, which is #2100603 in the Crystallography Open Database.

Tags: Bragg   historic   polyaromatic hydrocarbon   molecular