It's the unusual chemistry facilitated by this molecule, however, that will attract the most attention from scientists.
Marsha Lester, the University of Pennsylvania's Edmund J. Kahn Distinguished Professor, and Joseph Francisco, William E. Moore Distinguished Professor of Chemistry at Purdue University, found the molecule, which had puzzled and eluded scientists for more than 40 years.
A technical paper describing the molecule is published this week in a special edition of the Proceedings of the National Academy of Science.
Somewhat like a human body metabolizing food, the Earth's atmosphere has the ability to "burn," or oxidize pollutants, especially nitric oxides emitted from sources such as factories and automobiles. What doesn't get oxidized in the atmosphere falls back to Earth in the form of acid rain.
"The chemical details of how the atmosphere removes nitric acid have not been clear," Francisco says. "This gives us important insights into this process. Without that knowledge we really can't understand the conditions under which nitric acid is removed from the atmosphere."
Francisco says the discovery will allow scientists to better model how pollutants react in the atmosphere and to predict potential outcomes.
"This becomes important in emerging industrial nations such as China, India and Brazil where there are automobiles and factories that are unregulated," Francisco says. "This chemistry will give us insight into the extent that acid rain will be a future concern."
Lester says the molecule had been theorized by atmospheric chemists for 40 years and that she and Francisco had pursued it for the past several years.
"We've speculated about this unusual atmospheric species for many years, and then to actually see it and learn about its properties was very exciting," she says.
What makes the molecule so unusual is its two hydrogen bonds, which are similar to those found in water.
Chemists know that although water is one of the most common substances found on the planet, it has unusual properties. For example, the solid form - ice - is lighter than the liquid form and floats. Water also boils at a much higher temperature than would be expected from its chemical structure.
The cause of these strange behaviors are weak hydrogen bonds that hold water molecules together.
The new atmospheric molecule has two hydrogen bonds, which allows it to form a six-sided ring structure. Hydrogen bonds are usually weaker than the normal bonds between atoms in a molecule, which are known as covalent bonds. In fact, covalent bonds are 20 times stronger than hydrogen bonds. But in this case, these two hydrogen bonds are strong enough to affect atmospheric chemistry, Francisco says.
Lester says the new molecule exhibits its own unusual properties.
"The reaction involving this molecule proceeds faster as you go to lower temperatures, which is the opposite of most chemical reactions," she says. "The rate of reaction also changes depending on the atmospheric pressure, and most reactions don't depend on external pressure. The molecule also exhibits unusual quantum properties."
Lester says the unusual properties prevented scientists from being able to model the reaction for so long.
"This is not how we explain chemistry to high school students," she says.
Francisco says that this discovery will be used in areas other than atmospheric chemistry.
"Here's a situation where we were studying this purely environmental problem, but, because the findings are so fundamental, it may have broader ramifications to biological systems that depend on hydrogen bonds," he says.
The breakthrough was enabled by laser-based laboratory techniques at the University of Pennsylvania and the supercomputing resources available at Purdue, Francisco says. The computation was done on an SGI Altix supercomputer operated by the Office of Information Technology at Purdue.
"The key is knowing where to look and how to identify new chemical entities, and with the computing resources we have at Purdue we can help identify processes to within experimental uncertainty," he says. "We couldn't have done this without the supercomputing power that we have available."Writer: Steve Tally, (765) 494-9809, firstname.lastname@example.org
Steve Tally | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology