(Press-News.org)
In organic chemistry, π-stacking systems are supramolecular structures that arise due to the dispersion force, a type of intermolecular noncovalent interaction. They are a common occurrence in nature; the stabilized structure of DNA is a very prominent example of a π-stacking system, and so are the arrangement of amino acids in certain proteins. Interestingly, π-stacking can be leveraged in the design of materials with useful electronic and optical properties. These include organic semiconductors of various kinds, as well as conjugated polymers for sensing and biomedical applications.
Thus far, a good portion of technologically relevant π-stacking system has been limited to aromatic compounds, which have inherent π-electron clouds. On the other hand, antiaromatic compounds, though promising candidates for developing electric conductors, have been scarcely reported as the building units of π-stacking systems.
Surprisingly, in a recent study, a research team led by Professor Hiromitsu Maeda from Ritsumeikan University, Japan, reported a novel antiaromatic π-stacking system that enabled the formation of a highly conductive liquid crystal. Their findings were published on April 16, 2024, in the journal Chemical Science. Worth noting, this paper was co-authored by Prof. Go Watanabe from Kitasato University, Prof. Shu Seki from Kyoto University, and Prof. Hiroshi Shinokubo from Nagoya University.
The reported compounds in question are NiII-coordinated norcorroles with modified aryl moieties as side chains. Previously, achieving π-stacking in similar norcorroles failed because hydrogen-bonding interactions between the side chains opposed the face-to-face stacking of the planar antiaromatic units. This time, however, the research team had an ingenious idea. “We hypothesized that the introduction of side interacting moieties with less directionality would enhance the stacking between norcorrole units,” explains Prof. Maeda. “Thus, we attempted the simple introduction of aliphatic chains, which induce van der Waals interactions. These interactions can be effective for modulating the stacking structure of a material,” adds Prof. Maeda.
As evidenced through various experiments and molecular dynamics simulations, the proposed strategy worked as intended. The norcorrole units formed columnar structures through the stacking of arrangements known as ‘triple-decker.’ In these arrangements, a planarized molecule is sandwiched between two slightly bowl-shaped molecules.
Using the proposed molecular design, the researchers then synthesized liquid crystals. Thanks to the triple-decker stacking, a liquid crystal exhibited remarkable electric conductivity as well as thermotropicity; that is, an order parameter that depends on temperature. “The control of molecular interactions based on molecular design and synthesis, as demonstrated in our study, will be crucial for future applications,” remarks Prof. Maeda. “Properties such as high electric conductivity in liquid crystals may be used for the fabrication of electronic devices. In addition, stimuli-responsive behaviors in soft materials can be used to modulate relevant properties, like photoluminescence, according to pressure and temperature,” explains Prof. Maeda.
Taken together, the findings of this study bring to light a promising strategy for designing new compounds based on molecular assemblies of antiaromatic units. With any luck, this will open up new avenues for materials design, ultimately leading to better organic electronics, optoelectronics, and sensing devices.
***
Reference
DOI: https://doi.org/10.1039/D4SC01633E
About Ritsumeikan University, Japan
Ritsumeikan University is one of the most prestigious private universities in Japan. Its main campus is in Kyoto, where inspiring settings await researchers. With an unwavering objective to generate social symbiotic values and emergent talents, it aims to emerge as a next-generation research university. It will enhance researcher potential by providing support best suited to the needs of young and leading researchers, according to their career stage. Ritsumeikan University also endeavors to build a global research network as a “knowledge node” and disseminate achievements internationally, thereby contributing to the resolution of social/humanistic issues through interdisciplinary research and social implementation.
Website: http://en.ritsumei.ac.jp/
Ritsumeikan University Research Report: https://www.ritsumei.ac.jp/research/radiant/eng/
About Professor Hiromitsu Maeda from Ritsumeikan University, Japan
Dr. Hiromitsu Maeda is a professor at the Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University and a Ritsumeikan Advanced Research Academy (RARA) Fellow. He completed his PhD from Kyoto University in 2004. Professor Maeda’s research interests include topics like physical organic chemistry, supramolecular chemistry, and materials science on π-electronic systems. Prof. Maeda has received several prizes, including the ChemComm Emerging Investigator Lectureship (2012) and Fellow of the RSC (2015), and has over 200 publications.
Funding information
This work was supported by JSPS KAKENHI Grant Numbers JP18H01968, JP22H02067, and JP23K23335 for Scientific Research (B), JP19K05444 and JP2408389 for Scientific Research (C), JP23K17951 for Challenging Research (Exploratory), JP20H05862, JP20H05863, and JP20H05867 for Transformative Research Areas (A) “Condensed Conjugation”, JP19H05718 for Scientific Research on Innovative Areas “Aquatic Functional Materials”, Ritsumeikan Global Innovation Research Organization (R-GIRO) project (2017–22 and 2022–27), JST SPRING Grant Number JPMJSP2101, JST CREST Grant Number JPMJCR23O1, and the Sasakawa Scientific Research Grant from the Japan Science Society.
END
The first scientific pictures from the Euclid satellite mission have revealed more than 1,500 billion orphan stars scattered throughout the Perseus cluster of galaxies.
Led by astronomers from the University of Nottingham, this discovery sheds light on the origins of these celestial wanderers.
The Perseus cluster, located 240 million light-years away from Earth, is one of the Universe's most massive structures, boasting thousands of galaxies. However, amidst this cosmic ensemble, the Euclid satellite captured faint ghostly light - the orphan stars - drifting between the cluster's galaxies.
Stars naturally form within galaxies, so the presence of orphan ...
As the European Space Agency publishes the first findings from its Euclid space telescope, scientists from the University of Surrey are celebrating fresh insights from the data.
Dr Denis Erkal, Associate Professor of Astrophysics at the University of Surrey, studies how the gravity of the Milky Way pulls clusters of stars apart, creating streams of stars trailing across the galaxy.
Now, his model for how this happens (video HERE) has been confirmed by data from Euclid.
Dr Erkal said:
“For a long time, my modelling ...
Scientists have released the first set of scientific data captured with the Euclid telescope, showing an exciting glimpse of the Universe’s distant past.
The telescope, launched in July 2023, is part of the Dark Energy Satellite Mission, which aims to map the dark Universe.
Led by the European Space Agency in collaboration with The Euclid Consortium - which includes astronomers at The University of Manchester in leadership positions – the mission seeks to unlock mysteries of dark matter and dark energy and reveal how and why the Universe looks as it does today.
Early observations, described in a series ...
What should the medicine of the future look like? A team of scientists writing in Frontiers in Science lays out a bold vision for precision approaches to understanding, preventing, and treating diseases, driven by revolutionary technologies and new interdisciplinary collaborations between researchers and other health sector professionals. The internationally renowned authors – led by Prof Michel Goldman, recipient of the Blaise Pascal Medal 2024 for his exceptional contributions to immunology and healthcare innovation, and leading microbiologist Prof Philippe Sansonetti from the Institut Pasteur and Collège ...
Peer-reviewed - survey - people
Nurses who assess patients at emergency departments would like more training and say their decisions can be negatively impacted by the high pressures of their work.
Researchers at the University of East Anglia conducted the first ever UK survey of triage nurses to discover the background, training and decision-making processes of this role in emergency departments.
Lead author Hugh Gorick, a PhD researcher at UEA’s School of Health Sciences who also works as an assistant practitioner in an NHS hospital’s Acute Medical Unit, said: “More than 24 million patients present to emergency departments ...
Water scarcity will intensify with climate and socioeconomic change, disproportionately impacting populations located in the Global South. So concludes a new Utrecht University article published in Nature Climate Change on 23 May 2024, which used a state-of-the-art global water quantity and quality model to estimate clean water scarcity until the end of the century.
Humans require clean water for drinking and sanitation purposes, but also for the production of food, energy and manufactured goods. As communities and policymakers grapple with water scarcity issues on the ground, researchers ...
A small antibiotic called plectasin uses an innovative mechanism to kill bacteria. By assembling into large structures, plectasin latches onto its target on the bacterial cell surface comparable to how both sides of Velcro form a bond. A research team, led by structural biologist Markus Weingarth and biochemist Eefjan Breukink at Utrecht University, mapped how the Velcro-structure is formed. Their discovery, published in the scientific journal Nature Microbiology, unveils a new approach that could have broad implications for the development of antibiotics to ...
LOS ANGELES — World-renowned physicians and researchers from City of Hope®, one of the largest cancer research and treatment organizations in the United States, will present new data and offer expert perspectives on leading-edge cancer research and treatments in development at the 2024 ASCO Annual Meeting, which will take place in Chicago from May 31 to June 4. Highlights include the following:
2024 Best of ASCO® program: New data on mismatched unrelated donor peripheral blood stem cell transplantation
Late-breaking data on the phase 3 CodeBreaK 300 trial
Glofitamab monotherapy for patients ...
When it comes to the animal kingdom, bigger is better. Well, at least for proboscis monkeys, famously known for their long, large and droopy noses.
Researchers from The Australian National University (ANU) have provided a world-first explanation for why male proboscis monkeys have larger and “enhanced” nasal structures.
The researchers examined the bony nasal cavity inside the skulls of proboscis monkeys and found their large noses are more than just an eye sore and in fact offer several major benefits, especially when ...
About The Study: The results of this cohort study suggest that first-seizure clinic (FSC) attendance, particularly early attendance, was associated with reduced rates of subsequent hospital utilization. This knowledge may support adequately resourcing FSCs to improve equitable, timely access. Future study directions include assessing interventions that may support FSC attendance for at-risk groups.
Corresponding Author: To contact the corresponding author, Emma Foster, M.B.B.S.(Hons), Ph.D., email emma.foster@monash.edu.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamaneurol.2024.1187)
Editor’s ...