Byline: Anna ataline
The so -called Einstein is the so -called Einstein problem from standing at the intersection between mathematics and tiller trade. Despite its name, this mathematical question has nothing to do with the Nobel Prize winner Albert Einstein. It asks: Can you tile an endless surface with the same size (a “Einstein”) in such a way that the resulting pattern is never repeated? Such a “proto-tile” was first discovered in 2022 by English amateur mathematician David Smith.
EMPA researcher Carl-Henz Ernst is neither a mathematician nor a tiller. As a chemist, he researches the crystallization of molecules on metal surfaces. He never expected to deal with the Einstein problem in his professional life – until his doctoral student Jaan Woigat contacted him with unusual results of an experiment. When a certain molecule is crystallized on a silver surface, instead of the expected regular structure, irregular patterns were formed which never felt to repeat itself. Even more amazing: Every time they repeated the experiment, different eperodic patterns emerged.
Like all good researchers, Ernst and Voigat initially suspected an experimental error. But it soon became clear that strange discovery was real. The next step was to find out why the molecules behaved in such a unique way. Researchers recently published an answer to this question in the journal Nature Communications.
Unexpected effect
Ernsts and Voigat are interested in the so -called chirma, “assigned” which is characterized by many organic molecules. Although chirl structures are chemically similar, they cannot be rotated in each other – similar to our right and left hand. This property is particularly important in the pharmaceutical industry. All of all modern drugs are more than half. Since biomolecules such as amino acids, sugars and proteins in our body are all similar, active drug material should also be chilly. A drug with wrong hand is best ineffective and also the worst is harmful.
Controlling handing over during synthesis of organic molecules is therefore great interest in chemistry. One of the possibilities is crystallization of chirl molecules. It is used cheap, effective and widely – and has not yet been fully understood. EMPA researchers originally wanted to carry forward this understanding with their experiment. To do this, he took a very special molecule, a one that easily replaces his hands at room temperature – something that most chirl molecules never do practically.
“We expected molecules would be arranged in crystals according to their hand,” says Carl-Henn Ernst. Instead, the molecules randomly arranged themselves into triangles of different sizes, which in turn formed an irregular spiral on the surface-was a mistake that researchers initially thought that the researchers initially thought.
Puzzle pieces to physics
After a lot of esoteric, Voigt and Ernst finally managed to understand the molecular patterns – not only through physics and mathematics, but also on the computer or even with real puzzle pieces on the kitchen table at home Try The system of molecules is not completely random. They form triangles that measure between two and 15 molecules per side. In each experiment, a triangle shape dominated. What is more, the triangle was also represented by a size large and a size small – but no one else.
“Under our experimental conditions, molecules want to cover the silver surface as densely as possible because it is the most energetically favorable result,” Ernst says. “However, due to their saliva, the triangles they make, they do not fit at all on the edges and they have to offer a little offset.” Small and large triangles are required to fill the surface as efficiently. This arrangement also causes faults at some places – small anomalies or holes that can become the center of a spiral.
Antropi decides
“The defects are actually unfavorable in the context of energy,” the Ernst continues. “In this case, however, they enable a dense system of triangles, which compensates for ‘lost’ energy.” This balance also explains why researchers have never found the same pattern twice: If all the patterns are similar in terms of their energy costs, entropy takes decisions.
The mystery of “molecular Einstein” has been solved – but how does this insight benefit us? “Surfaces with defects at a atom or molecular level can have unique properties,” the Ernst tells. “Especially for an aperiodic surface like us, it is predicted that electrons will behave differently and it can give rise to a new type of physics.” However, to examine this, the epirodic molecule will have to study under the influence of magnetic fields on a separate surface. Carl-Henz Ernst, who recently retired, is leaving this task for others. “I have a little respect for physics,” smiles the chemist.
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