Unleashing Electron Affinity: The Remarkable Chemical Potential of Flat Fullerene Fragments
Even in the absence of the symmetrical and curved structure found in fullerenes, meticulously designed flat fullerene fragments that preserved the pentagonal substructure exhibited identical electron-accepting properties. Credit: YAP Co., Ltd
Fragments derived from spherical ‘Buckyball’ molecules possess stable electron-accepting capabilities with immense practical promise.
In Japan, researchers at Kyoto University have gained fresh insights into the distinctive chemical properties of spherical molecules composed entirely of carbon atoms, commonly known as fullerenes. They accomplished this by creating flattened fragments of these molecules, which surprisingly retained and even amplified certain crucial chemical properties. The team published their findings in the journal Nature Communications.
“Our work has the potential to unlock new opportunities across a wide range of applications, including semiconductors, photoelectric conversion devices, batteries, and catalysts,” says Aiko Fukazawa, the group leader at the Institute for Integrated Cell-Material Sciences (iCeMS).
Buckminsterfullerene, colloquially referred to as ‘buckyball,’ is a molecule comprising 60 carbon atoms bonded together to form a spherical structure. It derives its name from the structural resemblance to geodesic domes designed by the renowned architect Buckminster Fuller. Scientists have consistently been captivated by its unique architecture. The term ‘fullerenes’ is used to describe buckminsterfullerene and related spherical carbon clusters with varying numbers of carbon atoms, paying homage to Fuller’s name. One of the most intriguing characteristics of fullerenes is their ability to accept electrons, a process known as reduction. Due to their electron-accepting nature, fullerenes and their derivatives have been extensively investigated as materials for electron transport in organic thin-film transistors and organic photovoltaics. However, fullerenes deviate from conventional organic electron acceptors, exhibiting exceptional resilience in accepting multiple electrons.
Theoreticians in the field of chemistry have proposed three potential factors that may contribute to the electron-accepting capability of fullerenes: the high symmetry of the entire molecule, the pyramidally arranged carbon atoms, and the presence of pentagonal substructures interspersed among six-membered rings.
The team at Kyoto University focused their attention on the influence of pentagonal rings. They designed and synthesized flattened fragments of fullerenes, and through experimentation, confirmed that these molecules could accept an equivalent number of electrons to the count of five-membered rings in their structure without undergoing decomposition.
“This surprising discovery underscores the pivotal role played by pentagonal substructures in generating stable systems that can accept multiple electrons,” says Fukazawa.
Experiments also revealed that these fragments exhibited heightened absorbance of ultraviolet, visible, and near-infrared light compared to fullerenes themselves, which have more limited absorbance. This revelation could pave the way for novel applications in photochemistry, such as employing light to trigger chemical reactions or developing light sensors and solar-powered systems.
The team now intends to explore the potential of their flat fullerene fragments in a wide array of applications associated with electron-transfer processes. Achieving such high electron-accepting capabilities solely with carbon-based molecules, without the customary introduction of other electron-withdrawing atoms or functional groups, is unusual. However, further investigations into the incorporation of other atoms or chemical groups may yield additional control and versatility over chemical properties.
“We aspire to spearhead the science and technology of what we term ‘super-electron-accepting hydrocarbons’ by leveraging their considerable flexibility to explore the effects of structural modifications,” states Fukazawa.
Reference: “Flattened 1D fragments of fullerene C60 that exhibit robustness toward multi-electron reduction” by Masahiro Hayakawa, Naoyuki Sunayama, Shu I. Takagi, Yu Matsuo, Asuka Tamaki, Shigehiro Yamaguchi, Shu Seki, and Aiko Fukazawa, 15 May 2023, Nature Communications. DOI: 10.1038/s41467-023-38300-3
Frequently Asked Questions (FAQs) about electron-accepting capabilities
What are fullerenes and their significance in the field of chemistry?
Fullerenes are spherical molecules composed entirely of carbon atoms, with the most famous one being buckminsterfullerene or ‘buckyball.’ They have attracted scientific interest due to their unique structure and electron-accepting properties, making them promising materials for various applications.
How do flat fullerene fragments retain electron-accepting properties?
Despite lacking the symmetry and curvature of fullerenes, flat fullerene fragments maintain pentagonal substructures, which enable them to exhibit the same electron-accepting capabilities. These fragments can accept multiple electrons without decomposing, offering potential applications in various fields.
What practical applications can be derived from the electron-accepting properties of flat fullerene fragments?
The electron-accepting properties of flat fullerene fragments open up possibilities in areas such as semiconductors, photoelectric conversion devices, batteries, and catalysts. These fragments can be used in organic thin-film transistors, organic photovoltaics, and may even facilitate photochemical reactions and the development of light sensors and solar-powered systems.
What is the significance of pentagonal substructures in the electron-accepting capabilities of fullerenes?
The research suggests that pentagonal substructures play a crucial role in generating stable systems capable of accepting multiple electrons. The presence of these pentagonal rings in the flattened fullerene fragments allows for robust electron acceptance, contributing to their unique chemical properties.
Can the absorbance of light be enhanced by flat fullerene fragments?
Yes, experiments have shown that flat fullerene fragments display enhanced absorbance of ultraviolet, visible, and near-infrared light compared to fullerene molecules themselves. This enhanced absorbance opens up new possibilities in photochemistry, where light can be utilized to initiate chemical reactions or in the development of light sensors and solar-powered systems.
More about electron-accepting capabilities
- Nature Communications: Flattened 1D fragments of fullerene C60 that exhibit robustness toward multi-electron reduction
- Kyoto University: Institute for Integrated Cell-Material Sciences (iCeMS)
- Buckminster Fuller: Geodesic Domes
- Organic Electronics: Applications of Fullerenes in Organic Electronics