Researchers at Kyoto University in Japan have made significant strides in understanding the unique chemical properties of fullerenes, which are spherical molecules composed entirely of carbon atoms. By creating flattened fragments of these molecules, the researchers discovered that these fragments retained and even enhanced important chemical properties. The team published their findings in the journal Nature Communications.
The leader of the research group, Aiko Fukazawa, expressed excitement about the potential applications that could arise from this work, such as semiconductors, photoelectric conversion devices, batteries, and catalysts. Fullerenes, particularly buckminsterfullerene, which consists of 60 carbon atoms forming a spherical structure, have captivated scientists due to their distinctive architecture reminiscent of Buckminster Fuller’s geodesic domes. These spherical carbon clusters, including fullerenes with varying numbers of carbon atoms, are collectively referred to as fullerenes.
One of the most intriguing properties of fullerenes is their ability to accept electrons, known as reduction. This property has made them the subject of extensive research as electron-transporting materials in organic thin-film transistors and organic photovoltaics. However, fullerenes stand out from other organic electron acceptors due to their remarkable resistance to accepting multiple electrons.
Theoretical chemists have put forth three potential factors that may contribute to the electron-accepting ability of fullerenes: the overall molecule’s high symmetry, the carbon atoms with pyramidally arranged bonds, and the presence of pentagonal substructures interspersed among the six-membered rings.
The team from Kyoto University focused their investigation on the influence of the pentagonal rings. They designed and synthesized flattened fragments of fullerenes and successfully demonstrated that these molecules could accept electrons without decomposing, up to the number of five-membered rings present in their structure.
Fukazawa emphasized the significance of this surprising discovery, highlighting the pivotal role of pentagonal substructures in creating stable multi-electron accepting systems.
Furthermore, experiments revealed that the flattened fullerene fragments exhibited enhanced absorption of ultraviolet, visible, and near-infrared light compared to pristine fullerenes. This development opens up new possibilities in the field of photochemistry, including the initiation of chemical reactions using light and the development of light sensors or solar-powered systems.
The researchers now plan to explore the potential applications of their flattened fullerene fragments in various electron-transfer processes. It is noteworthy that these molecules, composed solely of carbon, exhibit such high electron-accepting ability without the need for additional electron-withdrawing atoms or functional groups. However, introducing other atoms or chemical groups may provide additional control and versatility over the chemical properties of these compounds.
Fukazawa expressed the team’s ambition to pioneer the science and technology of “super-electron-accepting hydrocarbons” by harnessing the freedom to explore the effects of structural modifications.
Overall, the research conducted by the Kyoto University team sheds light on the unique properties of fullerenes and their potential applications in a wide range of fields.
Source: Kyoto University