Smallest Possible Five-Ringed Structure Created

In honor of the upcoming Summer Olympics, the smallest possible five-ringed structure — just 1.2 nm in width and about 100,000 times thinner than a human hair — has been created and imaged using a combination of synthetic chemistry and state-of-the-art imaging techniques.

Dubbed olympicene, the five-ringed single molecule was created by the Royal Society of Chemistry (RSC), the University of Warwick and IBM Research two years after the design was entered on ChemSpider, RSC’s free online chemical database of more than 26 million records.

“When doodling in a planning meeting, it occurred to me that a molecular structure with three hexagonal rings about two others would make for an interesting synthetic challenge,” said professor Graham Richards, CBE, an RSC council member. “I wondered: Could someone actually make it and produce an image of the actual molecule?”

Olympicene radical AFM laplace filtered. The black bar corresponds to 0.5 nm. (Image: IBM Research – Zurich, University of Warwick, Royal Society of Chemistry)

Indeed, it could be done! University of Warwick chemists used synthetic organic chemistry to build the single molecule. It is similar to graphene and is one of a number of related compounds with electronic and optical properties, said Dr. David Fox of the university.

“Alongside the scientific challenge involved in creating olympicene in a laboratory, there’s some serious practical reasons for working with molecules like this,” Fox said. “For example, these types of molecules may offer great potential for the next generation of solar cells and high-tech lighting sources such as LEDs.”

The molecule was first glimpsed by Warwick scientists using scanning tunneling microscopy. To unravel its atomic-level anatomy, however, a higher resolution technique was needed.

To bring olympicene to life, IBM Research – Zurich scientists analyzed its chemical structure with unprecedented resolution using noncontact atomic force microscopy and achieved a single olympicene molecule.

“The key to achieving atomic resolution was an atomically sharp and defined tip apex as well as the very high stability of the system,” said Dr. Leo Gross of IBM. “We prepared our tip by deliberately picking up single atoms and molecules and showed that it is the foremost tip atom or molecule that governs the contrast and resolution of our AFM measurements.”

The chemical recipes used to create olympicene and other molecules are posted on the ChemSpider Synthetic Pages, where scientists can record and share the best ways to do specific reactions.

For more information, visit: www.rsc.org