Considered to be the smallest, most chemically inert and least polarizable of the 117 known chemical elements, helium has been challenging chemists for generations. unfortunately, no-one has managed to confirm experimentally the existence of either hebeo1 or hhef2, two important species previously predicted, nor a number of others.
The two new molecular species to bind helium to oxygen, predicted using theory, csfheo and nme4fheo (fig.2), are derivatives of a metastable [f– heo] anion first theorized in 2005 by a group from taiwan led by prof. hu. the scientist responsible for performing these new quantum chemical calculations is dr wojciech grochala from icm and the faculty of chemistry, the university of warsaw. speaking of his results, dr grochala said, "the molecules are not as peculiar as they might appear at first light; the idea is to preserve the metastable character of the fragile [f– heo] entity by attaching it to a weakly coordinating cation (such as cs+ or nme4 +) to achieve electric neutrality.
The resulting species exhibit a he–o bond with an electronic dissociation energy on the singlet potential energy surface (pes) as large as half an ev for the tetramethylammonium derivative." unfortunately, the kinetic stability of the molecules in question is limited by a crossing of the singlet–triplet pess and additionally by facile decomposition along the bending channel, both factors considerably limiting their lifetime. the implication for a realworld search for these molecules is that they should besought at a temperature of a few kelvin at most. commenting on how this could be achieved, dr grochala said, "the synthesis of both species might begin with the unusual hypofluorites, csof and nme4of, embedded in an ultracold helium droplet.
Laser excitation of the o–f chemical bond should allow for insertion of a helium atom into the bond and for spectroscopic observation of the short– living molecules. of course, such experiments are quite challenging but this is what makes modern chemistry so much fun". he added, "despite various difficulties i am really excited about the predictions".
Wojciech Grochala | alfa
Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
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
22.05.2018 | Life Sciences
22.05.2018 | Earth Sciences
22.05.2018 | Trade Fair News