The discovery, reported today in the journal Nature, involves trapping the carbene hydroxymethylene (HCOH) in a matrix of argon at 11 degrees Kelvin—just above absolute zero (¬?.67 degrees F)—where it was observed to decay, over a period of a few hours, to formaldehyde in a process that bears resemblance to the radioactive decay of nuclei.
While chemists had theorized for some years that HCOH should be isolable, this is the first time it has been achieved, and the accomplishment provides a greater understanding of the behavior of a class of compounds extremely important to organic and organometallic chemistry.
"It took a perfect match between experimental observations and theoretical predictions for us to say we have this molecule for the first time," said UGA chemist Wesley Allen, "but it worked beautifully, and this method can work for other elusive molecules as well."
Co-authors with Allen on the paper were Peter Schreiner and Hans Peter Reisenauer of Liebig University in Germany; Edit Mátyus and Attila Császár of Eötvös University in Hungary; and Frank Pickard and Andrew Simmonett, who along with Allen are with the department of chemistry at UGA. Schreiner received his doctoral degree from UGA and was on the faculty for several years before returning to Germany.
While the capture of HCOH is important, just as interesting is the team's unexpected discovery that the molecule decays to formaldehyde near absolute zero through "quantum tunneling," one of the more mystifying aspects of quantum theory. In quantum tunneling, a particle passes through a barrier that is impenetrable by normal standards.
"This kind of tunneling happens all the time with electrons, because they are so light," said Allen, "but for it to happen for heavier particles such as hydrogen atoms, the barriers must be more modest. In this case, the HCOH molecule tunnels under an enormous barrier, perhaps the most spectacular example of this process known in chemistry."
The reason why the group was studying HCOH at all began with a NASA project, since scientists at the space agency wanted to see if the elusive molecule existed in space but first needed to know what it would look like. Unfortunately, no one had been able to isolate and characterize it until the current research.
Allen and his UGA colleagues, who are theoretical chemists—studying chemistry by large-scale computations based on the laws of physics—say that it's now highly unlikely that free HCOH will be found in space.
"One of the most gratifying parts of this work is that we made the predictions of the tell-tale signatures of the molecule prior to the actual laboratory studies, which were done in Europe," said Allen, "so to us it helps prove the value of quantum chemistry in finding solutions in the lab."
While the signatures of HCOH were predicted, the quantum tunneling aspect came completely out of left field, Allen said, surprising everyone involved.
"Peter [Schreiner] called me up and said the decay mechanism was tunneling, because the molecule was perfectly stable when a heavy hydrogen isotope was inserted," said Allen. "I initially laughed at this idea. But I did the theory to see if it could be quantum tunneling, and sure enough we found out that it is what was happening in all likelihood. It was amazing."
Kim Osborne | EurekAlert!
Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo
Research reveals how order first appears in liquid crystals
23.05.2018 | Brown University
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy