Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

When atoms are getting close

06.05.2009
Shortest carbon-chlorine single bond detected until now

The description of compounds and interactions between atoms is one of the basic objectives of chemistry. Admittedly, chemical bonding models, which describe these properties very well, already exist.

However, any deviation from the normal factors may lead to improving the models further. Chemists with Professor Thomas M. Klapötke at Ludwig-Maximilians-Universität (LMU) München have now analyzed a molecule, which has an extremely short bond length.

As reported by the researchers in Nature Chemistry, the carbon atom and the chlorine atom in the so-called chlorotrinitromethane molecule are only 1.69 Angstroms apart from one another. "Non-covalent interactions are one of the factors responsible for this short distance", declared Göbel, whose doctoral thesis revealed the new results. "A better understanding of these interactions is important and useful in all areas, where molecular recognition and self-assembly come into play." (Nature Chemistry, 3 May 2009).

Chemical bond models that have been successfully used for well over a century assume that a good description of the properties of a compound can be obtained while ignoring all but the nearest-neighbour bonding interactions. The idea that electrostatic interactions between second, third and even further neighbors are important and should not be ignored has not been a common notion so far. The team of Professor Thomas M. Klapötke of the Department of Chemistry and Biochemistry at LMU Munich, primarily concerned with the synthesis and investigation of new high-energy materials, has now demonstrated for the first time that even second and third neighbors can have a decisive effect on the properties of a chemical bond.

For their investigation, the researchers chose the so-called chlorotrinitromethane molecule, a compound, consisting of the halogen chlorine and the pseudohalogen trinitromethyl group. The latter is composed of one carbon atom and three nitro groups. The trinitromethyl unit belongs to the group of pseudohalogens, which has properties similar to those of the halogens. Both groups are composed of non-metals, which are generally present in the gaseous or liquid state and form salts with metals. Contrary to the halogens, however, the pseudohalogens, instead of being true chemical elements, are chemical groups composed of different elements.

Using X-ray structural analysis, the researchers succeeded for the first time in revealing the internal structure of the chlorotrinitromethane molecule and drawing conclusions concerning the distances between the individual atoms. In their analyses, the chemists came up against a particularly interesting property of the chlorotrinitromethane molecule, namely the distance between its chlorine atom and its carbon atom is only 1.69 Angstroms. An Angstrom is 10-7 millimeters. The distance, now detected between the atoms, is the shortest distance ever observed for comparable chlorine-carbon single bonds. All previously measured distances fall within the range of approximately 1.71 and 1.91 Angstroms.

By means of theoretical calculations, carried out in cooperation with Professor Peter Politzer and Dr. Jane S. Murray of the University of New Orleans in the USA, the researchers were able to reproduce the distribution of electrical charges within the molecule. It turned out that the chlorine atom has a completely positive electrostatic potential, a rare case, since chlorine usually has a negative electrostatic potential in other molecules. Together with the charge distributions of the remaining atoms, this finding explains why the chlorine and carbon atoms are linked so tightly to one another. The results impressively show that electrostatic interactions between atoms within a molecule can have a significant effect on bond lengths, even if these atoms are not linked directly to one of the two atoms that form the bond.

In the case of chlorotrinitromethane, this effect is particularly pronounced and leads to an unusually short chlorine-carbon bond. However, it could be of importance in various other cases, especially in areas, where molecules recognize one another and assemble to larger structures. These mechanisms play an important role, for example, in biological systems and in nanotechnology.

Publication: "Chlorotrinitromethane and its exceptionally short carbon–chlorine bond";
Michael Göbel, Boris H. Tchitchanov, Jane S. Murray, Peter Politzer and Thomas M. Klapötke;
Nature Chemistry online,3 May 2009
DOI: 10.1038/nchem.179
Any correspondence should be addressed to:
Professor Thomas M. Klapötke
Department Chemistry and Biochemistry
Division Inorganic Molecule Chemistry
Phone.: +49-(0)89 / 2180 77504
Fax: +49-(0)89 / 2180 77492
E-mail: tmk@cup.uni-muenchen.de

Luise Dirscherl | EurekAlert!
Further information:
http://www.lmu.de
http://www.chemie.uni-muenchen.de/ac/klapoetke/

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>