OIST researchers design new photoluminescent compounds
Chemical compounds that emit light are used in a variety of different materials, from glow-in-the-dark children's toys to LED lights to light-emitting sensors. As the demand for these compounds increases, finding new efficient methods for their production is essential.
New research from the Coordination Chemistry and Catalysis Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) describes a new strategy for producing photoluminescent (PL) compounds with increased capabilities. This research was recently published in the Journal of Materials Chemistry C.
Production of PL compounds is typically centered around two main methods: the conventional metal-ligand system or an aggregation based system. The first method requires a complex ligand, or compound, that strongly binds to a metal ion in a way that would allow for the complex to emit light of certain wavelength. Unfortunately, this system is rigid and unable to be modified once the complex is produced.
In contrast, the aggregation-based system is driven by weak interactions between different molecules or their parts. This allows for tunability by shifting the color of light emitted based on interactions of the PL compound with the local environment. However, aggregation is typically difficult to control and thus not feasible to use in systems requiring precision.
Recent research from OIST scientists combines the best parts of both methods to produce PL molecules. "We wanted to create better photoluminescent compounds by combining the two previous concepts: the flexibility of the weak aggregation driven complexes and the controllability of the conventional metal-ligand system", explained Dr. Georgy Filonenko, postdoctoral researcher from the Coordination Chemistry and Catalysis Unit at OIST.
Researchers, led by Prof. Julia Khusnutdinova, designed compounds whose photoluminescence depended on weak interactions between atoms within the single compound molecule itself. As a result, they obtained the tunability of the aggregation-based system confined to a single molecule, without the need for intermolecular aggregation.
Akin to the conventional metal-ligand system, the molecules synthesized by Filonenko consist of a ligand and a copper ion which interact to produce photoluminescence. However, the ligand in the OIST-synthesized molecules is not rigid and has two cyclic-bonded atom structure, referred to as rings, stacked on top of one another that can interact just like in the aggregation system, but within a single molecule. Interestingly, researchers discovered that they could adjust the color emitted from these molecules based on the distance between these rings.
"We found that we could change the color produced by the compound based on what other groups of atoms were bound to the ligand," illuminates Filonenko. "Larger groups would cause the rings to move closer together, shifting the color to the orange-yellow range, while smaller substituents would make the rings move apart, turning the emission color red. The ability to tune the wavelength of light emitted from these molecules provides a huge advantage over the traditional metal-ligand PL complexes".
The tunability and controllability of these complexes makes them an attractive candidate for many applications. "We see a high potential for these compounds to be used as sensors due to their very high sensitivity to the surrounding environment," revealed Filonenko.
Kaoru Natori | EurekAlert!
Borophene shines alone as 2-D plasmonic material
21.11.2017 | Rice University
Quantum dots amplify light with electrical pumping
21.11.2017 | DOE/Los Alamos National Laboratory
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences