(Press-News.org) CAMBRIDGE, MA -- Chains of fused carbon-containing rings have unique optoelectronic properties that make them useful as semiconductors. These chains, known as acenes, can also be tuned to emit different colors of light, which makes them good candidates for use in organic light-emitting diodes.
The color of light emitted by an acene is determined by its length, but as the molecules become longer, they also become less stable, which has hindered their widespread use in light-emitting applications.
MIT chemists have now come up with a way to make these molecules more stable, allowing them to synthesize acenes of varying lengths. Using their new approach, they were able to build molecules that emit red, orange, yellow, green, or blue light, which could make acenes easier to deploy in a variety of applications.
“This class of molecules, despite their utility, have challenges in terms of their reactivity profile,” says Robert Gilliard, the Novartis Associate Professor of Chemistry at MIT and the senior author of the new study. “What we tried to address in this study first was the stability problem, and second, we wanted to make compounds where you could have a tunable range of light emission.”
MIT research scientist Chun-Lin Deng is the lead author of the paper, which appears today in Nature Chemistry.
Colorful molecules
Acenes consist of benzene molecules — rings made of carbon and hydrogen — fused together in a linear fashion. Because they are rich in sharable electrons and can efficiently transport an electric charge, they have been used as semiconductors and field-effect transistors (transistors that use an electric field to control the flow of current in a semiconductor).
Recent work has shown that acenes in which some of the carbon atoms are replaced, or “doped,” with boron and nitrogen have even more useful electronic properties. However, like traditional acenes, these molecules are unstable when exposed to air or light. Often, acenes have to be synthesized within a sealed container called a glovebox to protect them from air exposure, which can lead them to break down. The longer the acenes are, the more susceptible they are to unwanted reactions initiated by oxygen, water, or light.
To try to make acenes more stable, Gilliard decided to use a ligand that his lab has previously worked with, known as carbodicarbenes. In a study published last year, they used this ligand to stabilize borafluorenium ions, organic compounds that can emit different colors of light in response to temperature changes.
For this study, Gilliard and his co-authors developed a new synthesis that allowed them to add carbodicarbenes to acenes that are also doped with boron and nitrogen. With the addition of the new ligand, the acenes became positively charged, which improved their stability and also gave them unique electronic properties.
Using this approach, the researchers created acenes that produce different colors, depending on their length and the types of chemical groups attached to the carbodicarbene. Until now, most of the boron, nitrogen-doped acenes that had been synthesized could emit only blue light.
“Red emission is very important for wide-ranging applications, including biological applications like imaging,” Gilliard says. “A lot of human tissue emits blue light, so it’s difficult to use blue-fluorescent probes for imaging, which is one of the many reasons why people are looking for red emitters.”
Better stability
Another important feature of these acenes is that they remain stable in both air and water. Boron-containing charged molecules with a low coordination number (meaning the central boron atom has few neighbors) are often highly unstable in water, so the acenes’ stability in water is notable and could make it feasible to use them for imaging and other medical applications.
“One of the reasons why we're excited about the class of compounds that we're reporting in this paper is that they can be suspended in water. That opens up a wide range of possibilities,” Gilliard says.
The researchers now plan to try incorporating different types of carbodicarbenes to see if they can create additional acenes with even better stability and quantum efficiency (a measure of how much light is emitted from the material).
“We think it will be possible to make a lot of different derivatives that we haven't even synthesized yet,” Gilliard says. “There are a lot of optoelectronic properties that can be dialed in that we have yet to explore, and we're excited about that as well.”
Gilliard also plans to work with Marc Baldo, an MIT professor of electrical engineering, to try incorporating the new acenes into a type of solar cell known as a single-fission-based solar cell. This type of solar cell can produce two electrons from one photon, making the cell much more efficient.
These types of compounds could also be developed for use as light-emitting diodes for television and computer screens, Gilliard says. Organic light-emitting diodes are lighter and more flexible than traditional LEDs, produce brighter images, and consume less power.
“We're still in the very early stages of developing the specific applications, whether it's organic semiconductors, light-emitting devices, or singlet-fission-based solar cells, but due to their stability, the device fabrication should be much smoother than typical for these kinds of compounds,” Gilliard says.
###
The research was funded by the Arnold and Mabel Beckman Foundation and the National Science Foundation Major Research Instrumentation Program.
END
Chemists create organic molecules in a rainbow of colors
The molecules, known as acenes, could be useful as organic light-emitting diodes or solar cells, among other possible applications
2023-12-05
ELSE PRESS RELEASES FROM THIS DATE:
NCCN summit navigates solutions for financial and other cancer-related hardships
2023-12-05
PLYMOUTH MEETING, PA [December 5, 2023] — Today, the National Comprehensive Cancer Network® (NCCN®)—an alliance of leading cancer centers—hosted a Patient Advocacy Summit to explore the role of navigation throughout the cancer process. A diverse group of subject matter experts addressed the impact patient navigation has on care and how to utilize navigators to reduce economic burdens and disparities in care. The speakers included patients and advocates, policymakers, health care providers, and health data analysts.
The summit featured a series of best practice presentations highlighting some of the tools available to assist in various ...
Incarcerated women punished at higher rates for minor infractions than men, UTEP study shows
2023-12-05
EL PASO, Texas (Dec. 5, 2023) – A new study from The University of Texas at El Paso reveals a gender disparity in prison infractions that disproportionately affects women.
The study, led by Melinda Tasca, Ph.D., an associate professor in the Department of Criminal Justice and Security Studies at UTEP, and published in Justice Quarterly, analyzed the disciplinary infraction records of more than 20,000 males and females in a large western state prison, who were released between 2010 and 2013.
The researchers set out to answer three questions: ...
Conference on microplastics in water: characterization, cure and prevention
2023-12-05
Plastics are ubiquitous in all aspects of modern life, including food packaging, health care and household products. There has been a massive increase in plastics production over the past several decades and there has been serious attention paid to managing plastic wastes, particularly focused on recycling/reuse. However, as of the present time it has not been feasible, either technically or economically, to achieve a fully circular system. Those plastic materials that are not processed for reuse, known as end-of-life pastics, end up in landfillsor in other waste processing systems (e.g., incineration) or advanced recycling (eg., pyrolysis) or directly disposed in the ...
Dorothee Dormann receives an ERC Consolidator Grant to support her research into neurodegenerative diseases
2023-12-05
The protein TDP-43 is present in all cells of our body and important for their biochemical processes. However, this protein can aggregate into large clumps in the brain, which can cause degenerative diseases such as Alzheimer's and other dementias. How exactly this happens and how these protein clumps are linked to disease is a subject of intense research. Professor Dorothee Dormann of Johannes Gutenberg University Mainz (JGU) suspects that these proteins may also assemble in healthy cells – and that this assembly on a much smaller scale is important for the normal function of the TDP-43 protein. Her research group investigates the reason for these assemblies in ...
Reducing the energy consumption of software: Sebastian Erdweg receives ERC Consolidator Grant
2023-12-05
The energy consumption of data centers and information and communication technology (ICT) devices is growing at an alarming rate, projected to constitute up to 20 percent of global energy consumption by 2030. To support the digital transformation effectively, we need to enhance software efficiency. A promising avenue in this endeavor is incremental computing, where computations react to input changes rather than recomputing results from scratch. However, existing approaches to incrementality have limited applicability: They either demand expert knowledge, support only specialized domains (e.g., ...
Study finds plant nurseries are exacerbating the climate-driven spread of 80% of invasive species
2023-12-05
AMHERST, Mass. – Researchers at the University of Massachusetts Amherst recently published a pair of papers that, together, provide the most detailed maps to date of how 144 common invasive plants species will react to 2° Celsius of climate change in the eastern U.S., as well as the role that garden centers currently play in seeding future invasions. Together, the papers, published in Diversity and Distributions and BioScience, and the publicly available maps, which track species at the county level, promise to give invasive species managers in the U.S. the tools they need ...
Jefferson Lab site grows with addition of Applied Research Center
2023-12-05
NEWPORT NEWS, VA – The Applied Research Center (ARC) is tying the knot with the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility. Today, the City of Newport News announced the transfer of the Applied Research Center to Jefferson Lab and the DOE. The announcement was made in a ribbon-tying ceremony for the facility.
“Newport News is a hub of innovation and research, thanks in large part to Jefferson Lab’s robust educational and scientific offerings,” said Newport News Mayor Phillip Jones. “Since 1985, the city has invested more than $64 ...
Texas A&M receives $1.8 million NIH grant to support bone health in people with down syndrome
2023-12-05
By Courtney Price, Texas A&M University School of Veterinary Medicine & Biomedical Sciences
Texas A&M University researchers have been awarded a $1.8 million grant from the National Institutes of Health (NIH) to study bone regeneration throughout the lifespan to ultimately benefit individuals with Down syndrome.
The new INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE (INCLUDE) Project grant will help scientists understand whether bone regeneration holds the key to helping people ...
Membrane raft redox signaling contributes to visfatin-induced inflammation and kidney damage
2023-12-05
“[...] the exact mechanism of how obesity increases the advancement of chronic kidney disease is still uncertain.”
BUFFALO, NY- December 5, 2023 – A new research paper was published in Aging (listed by MEDLINE/PubMed as "Aging (Albany NY)" and "Aging-US" by Web of Science) Volume 15, Issue 22, entitled, “Contribution of membrane raft redox signalling to visfatin-induced inflammasome activation and podocyte injury.”
The number of obese patients with end-stage renal disease has ...
New study highlights COVID-19’s adaptive strategy for infection
2023-12-05
MINNEAPOLIS/ST. PAUL (12/05/2023) – Researchers have discovered a novel mechanism whereby the SARS-CoV-2 virus, which causes COVID-19, can vary its mode of infection in human cells. Published in the journal eLife, a team from the University of Minnesota and the Midwest Antiviral Drug Discovery (AViDD) Center found the virus can alternate between being highly infectious and avoiding detection by the immune system. This understanding is vital for grasping the virus' impact during the pandemic and for predicting its potential evolutionary developments.
The spike protein of the virus, which is crucial for attaching ...
LAST 30 PRESS RELEASES:
Insulin resistance is linked to over 30 diseases – and to early death in women, study of people in the UK finds
Innovative semaglutide hydrogel could reduce diabetes shots to once a month
Weight loss could reduce the risk of severe infections in people with diabetes, UK research suggests
Long-term exposure to air pollution and a lack of green space increases the risk of hospitalization for respiratory conditions
Better cardiovascular health in early pregnancy may offset high genetic risk
Artificial intelligence method transforms gene mutation prediction in lung cancer: DeepGEM data releases at IASLC 2024 World Conference on Lung Cancer
Antibody–drug conjugate I-DXd shows clinically meaningful response in patients with extensive-stage small cell lung cancer
IASLC Global Survey on biomarker testing reveals progress and persistent barriers in lung cancer biomarker testing
Research shows pathway to developing predictive biomarkers for immune checkpoint inhibitors
Just how dangerous is Great Salt Lake dust? New research looks for clues
Maroulas appointed Associate Vice Chancellor, Director of AI Tennessee
New chickadee research finds cognitive skills impact lifespan
Cognitive behavioral therapy enhances brain circuits to relieve depression
Terasaki Institute awarded $2.3 Million grant from NIH for organ transplantation research using organs-on-a-chip technology
Atoms on the edge
Postdoc takes multipronged approach to muon detection
Mathematical proof: Five satellites needed for precise navigation
Scalable, multi-functional device lays groundwork for advanced quantum applications
Falling for financial scams? It may signal early Alzheimer’s disease
Integrating MRI and OCT for new insights into brain microstructure
Designing a normative neuroimaging library to support diagnosis of traumatic brain injury
Department of Energy announces $68 million in funding for artificial intelligence for scientific research
DOE, ORNL announce opportunity to define future of high-performance computing
Molecular simulations, supercomputing lead to energy-saving biomaterials breakthrough
Low-impact yoga and exercise found to help older women manage urinary incontinence
Genetic studies reveal new insights into cognitive impairment in schizophrenia
Researcher develops technology to provide cleaner energy and cleaner water
Expect the unexpected: nanoscale silver unveils intrinsic self-healing abilities
nTIDE September 2024 Jobs Report: Gains in employment for people with disabilities appear to level off after reducing gaps with non-disabled workers
Wiley enhances NMR Spectral Library Collection with extensive new databases
[Press-News.org] Chemists create organic molecules in a rainbow of colorsThe molecules, known as acenes, could be useful as organic light-emitting diodes or solar cells, among other possible applications