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!
Atomic structure of ultrasound material not what anyone expected
21.02.2018 | North Carolina State University
Hidden talents: Converting heat into electricity with pencil and paper
20.02.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
21.02.2018 | Materials Sciences
21.02.2018 | Health and Medicine
21.02.2018 | Physics and Astronomy