Researchers from Virginia Commonwealth University, McNeese State University in Lake Charles, La., and the University of Konstanz in Germany report their discovery in the Oct. 6 international chemistry journal Angewandte Chemie International Edition. The journal designated the paper as “very important,” recognition granted to only 5 percent of papers it receives.
Chlorine is one of the elements called halogens, a group that includes fluorine, bromine, and iodine. These chemicals are known for their disinfecting and deodorizing power and are also used in some medications and industrial processes. Researchers say that hyperhalogens could be useful in industries where large amounts of halogens are now needed to make cleaning or decontamination products.
Chemists and physicists like Puru Jena, Ph.D., distinguished professor of physics at VCU, know halogens for their reactivity, a characteristic that makes the halogen elements want to bond with another element or a compound by taking one electron. Chlorine, for example, likes being paired with sodium to make table salt. Sodium wants to give away an electron and chlorine wants to take that electron in what Jena calls “a perfect marriage.”
“Halogens only need one electron to reach their happy state,” said Jena. “They’re much more stable as a negative ion than as a neutral atom.”
Once the atom takes an electron and becomes a stable, negative ion, the energy it gains is measured by its electron affinity. In chemistry’s periodic table, chlorine has the highest electron affinity, measured at 3.6 electron volts, or eV.
One area of Jena’s research focuses on finding ways to make new classes of compounds with large electron affinities.
In 1962, English chemist Neil Bartlett found that platinum hexafluoride reacts with xenon to make a noble gas compound. Scientists were surprised because xenon was one of the stable or “noble” gases that rarely react with other elements. A dozen years later, two Soviet scientists, Gennady Gutsev and Alexander Boldyrev, showed that a larger class of molecules with a metal atom at the center surrounded by halogen atoms, similar to platinum hexafluoride, possesses electron affinities larger than that of chlorine. They termed these molecules “superhalogens.”
“For example, you could take a sodium atom and a chlorine atom to make a sodium chloride molecule and then attach a second chlorine atom. That compound would then want another electron because of the extra chlorine,” Jena said. “All of a sudden, the electron affinity, which is the characteristic we’re after, becomes almost a factor of two larger than that of the chlorine atom. It becomes a superhalogen.”
Superhalogens have similar, improved properties as halogens, Jena said.
Jena, together with Anil Kandalam, Ph.D., assistant professor at McNeese State University, theorized that they could push the electron affinity of a cluster or a molecule even higher, by using superhalogens as building blocks, instead of halogens, around a metal atom. The theoretical model was tested through experimental studies led by Gerd F. Ganteför, Ph.D., at the University of Konstanz. They termed these species with unusually large electron affinities as “hyperhalogens.”
“We used gold as the metal and surrounded it with two boron-dioxide superhalogens and got a hyperhalogen with an even greater electron affinity,” Jena said.
The team’s synergistic approach involving theory and experiment produced a gold-borate hyperhalogen with an electron affinity of 5.7 eV. The team now is testing a hyperhalogen constructed with four boron-dioxide superhalogens and have reached an electron affinity of 7 eV, with a goal of building a hyperhalogen with 10 eV. These new hyperhalogens may lead to additional discoveries of novel chemicals, Jena said.
The theoretical investigations for the project were conducted by Jena and graduate student Mary Willis at VCU, along with Kandalam. The experimental work was conducted by Ganteför and graduate student Matthias Götz at the University of Konstanz.
The work was supported in part by the federal Defense Threat Reduction Agency and the Department of Energy.
About VCU and the VCU Medical Center: Virginia Commonwealth University is a major, urban public research university with national and international rankings in sponsored research. Located on two downtown campuses in Richmond, VCU enrolls more than 32,000 students in 211 certificate and degree programs in the arts, sciences and humanities. Sixty-nine of the programs are unique in Virginia, many of them crossing the disciplines of VCU’s 13 schools and one college. MCV Hospitals and the health sciences schools of Virginia Commonwealth University compose the VCU Medical Center, one of the nation’s leading academic medical centers.
Sathya Achia Abraham | Newswise Science News
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences