Ученые создали новое поколение стекол с магнитными и светящимися свойствами

Researchers crack the code: Molecular trick opens the door to a new generation of glass MOF glasses with new properties: an organic molecule alters the bonding structure during melting Advertisement Glasses with special properties “We have found a way to chemically modify the structure of glasses derived from so-called metal-organic framework compounds – or MOFs for short – right during the manufacturing process,” explains Prof. Dr. Sebastian Henke from TU Dortmund University, who led the study. To achieve this, the experts used 1,10-phenanthroline. The molecule lowers the melting point whilst simultaneously altering how the metal atoms in the glass are bonded together. The major advantage is that researchers could thus develop glasses with magnetic or light-emitting properties that were previously impossible to achieve without destroying the material through extreme heat. Glass transformed from within through chemical modification “Normally, glass is formed when a molten liquid cools rapidly. The solid structure then sets without the atoms arranging themselves in a regular pattern. Until now, researchers often had to accept the chemistry of these glasses as dictated by the starting material,” explains Prof. Henke. The team has now shown that this does not always have to be the case. This is because MOFs consist of metal centres held together by organic compounds. These structures can be fundamentally altered whilst in a liquid state by adding phenanthroline. “The crucial point is that the molecule does not simply remain as a filler,” Prof. Henke continues. “It enters into a reaction. So we are altering the chemistry at precisely the moment when the material is still liquid.” The molecular key The scientists mixed the phenanthroline with the starting materials before heating. The additive fulfils two functions at once: “As a flux, the substance lowers the temperature at which the material melts; as a chemical agent, the molecule binds directly to the metal atoms and partially displaces old bonds. In the molten state, the molecule interferes with what is known as the coordination environment. This term describes how many neighbours surround a single atom. Because the new molecule binds more strongly to the metal centres, the number of neighbours increases,” explains Prof. Henke. The process initiates a complete restructuring of the glass network. By adjusting the dosage of the molecule, the researchers can control the extent of this restructuring. Lower-temperature production, more stable results A practical side-effect of the process is the lower melting temperature. Many of the materials studied would otherwise decompose before they could be turned into glass. Extreme heat would destroy their structure and produce unwanted impurities. “Thanks to this molecular trick, the material melts at significantly lower temperatures and remains stable. Studies on cobalt-containing glasses have shown that this gentler process prevents the formation of harmful decomposition products,” explains Prof. Dr. Matthias Bauer from Paderborn University. This is particularly important for functional properties: it is the only way to detect the pure magnetic effects in the glass, which would otherwise have been masked by impurities. Measurements confirm hypothesis High-resolution measurement methods were employed to prove that the structure had indeed changed. Conventional X-ray techniques reach their limits here, as the glass no longer exhibits a regular crystal structure. Prof. Bauer explains: “Instead, we used X-ray absorption spectroscopy, amongst other techniques. This method enabled us to investigate the immediate surroundings of the cobalt atoms.” The measurement data confirmed the hypothesis: whilst the atoms retain their chemical state (oxidation state), their spatial environment changes significantly. The bonds to neighbouring molecules adapt to the new molecule. From crystal to functional component The study shows that the process is not limited to a single class of materials. The researchers also successfully tested their method on so-called carboxylate-based scaffold structures. This significantly expands the possibilities for manufacturing the glasses. Prof. Henke summarises the significance for the future: “The melt is no longer a rigid intermediate state. It becomes a reaction space in which we can programme the structure.” This control offers prospects for future applications. In future, organometallic glasses could be used in catalysis, as sensors, or in optoelectronics. As the metal centres can now be specifically manipulated, new avenues are opening up for the development of components that precisely control light, magnetism, or chemical reactions. Original publication Other news from the department science Most read news More news from our other portals See the theme worlds for related content Topic World Spectroscopy Investigation with spectroscopy gives us unique insights into the composition and structure of materials. From UV-Vis spectroscopy to infrared and Raman spectroscopy to fluorescence and atomic absorption spectroscopy, spectroscopy offers us a wide range of analytical techniques to precisely characterize substances. Immerse yourself in the fascinating world of spectroscopy! Topic World Spectroscopy Investigation with spectroscopy gives us unique insights into the composition and structure of materials. From UV-Vis spectroscopy to infrared and Raman spectroscopy to fluorescence and atomic absorption spectroscopy, spectroscopy offers us a wide range of analytical techniques to precisely characterize substances. Immerse yourself in the fascinating world of spectroscopy!