Chemists Find New Way to Synthesize ‘Olympic Ring’ Molecule

A team of researchers at Florida State University has unlocked a new strategy for synthesizing of olympicene (a molecule consisting of five rings that resemble the shape of the famous Olympic rings) and other polyaromatic compounds such as phenalenes and benzanthrenes.

In the new technique, an additional hexagonal ring of carbon atoms is fused to the zigzag edge of an existing carbon-rich molecule in two quick steps. Image credit: Igor Alabugin.

Olympicenes are like the decathletes of nanoscale molecules. Their range of potential applications include sophisticated sensors, information and energy storage, solar cells and high-tech LEDs.

The first olympicene molecule was unveiled by a team of British chemists in anticipation of the 2012 London Olympics.

Until now, synthesizing these unique structures was only possible through an arduous and intensive seven-step process based largely on chemistry dating back to the 1960s.

In the team’s new technique, an additional hexagonal ring of carbon atoms is fused to the zigzag edge of an existing carbon-rich molecule in two quick steps.

“Our success in developing this strategy allowed us to accomplish a two-step synthesis that is much shorter than the previously reported route, even though both methods used the same starting material,” said team leader Professor Igor Alabugin, from the Department of Chemistry and Biochemistry at Florida State University.

Soon after olympicenes were successfully synthesized, chemists recognized the important connection they shared with graphene.

Now, with their new strategy for accelerated olympicene synthesis, Professor Alabugin and colleagues may have revealed a way to better facilitate the production of what some have dubbed a ‘miracle material.’

“Our approach will allow chemists to synthesize a variety of olympicenes that can serve as stepping stones for the preparation of precisely shaped and functionalized graphene substructures,” Professor Alabugin said.

In honor of the 2018 Olympic Winter Games, the authors christened the product of their innovative synthesis strategy ‘Ph-olympicene’ — the ‘P’ reflecting both the phenyl group crucial to the synthesis of the molecule and a subtle nod to the host city PyeongChang.

“The exact timeline for designing, discovering and then having your findings peer reviewed is never certain,” Professor Alabugin said.

“Publishing this new synthesis of olympicene just in time for the Winter Olympics is indeed a fortunate coincidence.”

The results are published in the journal Angewandte Chemie.

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Nikolay Tsvetkov et al. Radical Alkyne Peri-annulations for Synthesis of Functionalized Phenalenes, Benzanthrenes, and Olympicene. Angewandte Chemie, published online February 5, 2018; doi: 10.1002/ange.201712783