17.02.17.Researchers use new approach to create triangulene molecule.
(Phys.org)—A team of researchers with IBM Research in Switzerland and the University of Warwick in the U.K. has successfully created a triangulene molecule by manipulating a precursor molecule physically using a scanning probe microscope tip. In their paper published in the journal Nature Nanotechnology, the team describes their approach and what they have learned about the molecule's properties thus far. Manuel Melle-Franco with the University of Aveiro in Portugal offers a News & Views piece on the work done by the team in the same journal issue.
A triangulene molecule, as its name suggests, is a hydrocarbon molecule that is shaped like a triangle—it is also flat because it is just one atom thick—chemists have been trying in vain for years to synthesize such molecules because of their expected unique properties, but have failed due to the instability of unpaired electrons. In this new effort, the researchers took a new approach, using a scanning probe microscope tip to nudge pieces into place and then to tear away the parts that were not needed.
To create the molecule, the researches began with a dihydrotriangulene molecule because it did not have the reactive unpaired electrons—they used it as a precursor, laying it on a base (they tried xenon, copper and salt) and then probing it with the electron microscope tip to get the molecules to align in the desired way. Next, they fired an electron beam at the molecule two times to remove the hydrogen, leaving behind a triangulene. The team then created an image of the molecule they had created using the same microscope, which showed its unique triangular shape. They also found they were able to keep the molecule stable as long as they kept it in a vacuum at low temperatures. In testing the molecule, they found that its two unpaired electrons had aligned spins, which was expected. That property was one of the reasons that chemists have been trying to synthesize the molecule—it is believed it could prove very useful in various electronic devices and might even have applications in a quantum computer.
The research team plans to continue their work with creating triangulene molecules to learn more about their properties and possible uses. They also hope to find out why their technique worked when a copper bases was used—they thought the two materials would react.