Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The hidden side of sulfur

14.12.2016

Synthetic organic chemistry consists of transforming existing molecules into new molecular structures or assemblies. These new molecular systems are then used in a myriad of ways in everyday life - in a wide range of sectors, such as public health, energy and environment, for use in drugs, solar cells, fragrances, and so on.

The active element in the molecule that initiates these transformations, known as the catalyst, is often hydrogen. However, a research team at the University of Geneva (UNIGE), Switzerland, has found that a sulfur atom, if carefully inserted into a molecule, can not only become an extremely effective catalyst but can also operate with greater precision. This discovery, published in Angewandte Chemie, has the potential to revolutionize the world of synthetic organic chemistry. It paves the way for the creation of new molecules that can be used in our daily life.


Highly electron-deficient, dark blue holes appear on the surface of sulfur atoms in the SF2 molecule, and on one of the best of the 'sulfurous' catalysts created by Professor Matile's group.

Credit: ©UNIGE

Creativity in fundamental research in chemistry consists of finding new ways to transform molecules and to build new molecular structures. To achieve this, the starting molecule needs to undergo a series of transformations until the molecular architecture of interest is achieved.

However, a molecule does not just change by itself - it has to be pushed by another molecule, the so-called catalyst. In nature, enzymes play this catalytic role. In chemistry and biology, the active element in catalysts is often the smallest possible atom - hydrogen.

"When we want to carry out a molecular transformation, we frequently use the hydrogen bond," explains Stefan Matile, Professor in the Department of Organic Chemistry in the Faculty of Science at UNIGE, and director of the research project. "More precisely, we place the molecule that we want to transform, known as the substrate, in contact with hydrogen. The catalyst then attracts negative charge from the substrate, to the point where the molecule is so poor in negative charges that it is forced to seek contact with another substrate and, in order to maintain itself, to transform." Hydrogen can be thought of as a vacuum cleaner that aspirates negative charges until the molecules are forced to come together and transform to compensate for the loss.

Sulfur increases precision

Professor Matile's team is interested in using bonds other than hydrogen bonds for catalysis and other activities. Most chemists consider these to be rather esoteric with little importance in the area of molecular transformation. However, when looking more closely at the sulfur atom in certain molecules, the UNIGE research team realized that the atom has a very localized area where it is extremely deficient in electrons, a sort of 'black hole'.

The team wanted to know whether this hole could act as a 'vacuum cleaner', like hydrogen, if it were placed in contact with a substrate. If this were the case, sulfur could be used as a catalyst, causing molecules to transform themselves. This somewhat unorthodox bond, known as a chalcogen bond, would thus replace the conventional hydrogen bond.

As Professor Matile further explains: "To test our hypothesis, we created and tested a series of molecular structures using chalcogen bonds of gradually increasing strength. We noticed that they not only work, but that they increase the speed of the transformation by more than a thousand times, as when there is no catalyst. Additionally, we achieved a degree of precision that is impossible with hydrogen bonds." In fact, hydrogen's entire surface is 'electron poor'.

Thus, when it is playing the role of catalyst, the entire atom can come into contact with the substrate and suck up negative charges all over. However, with sulfur, only a small area can act as catalyst. This will enable chemists to be more precise in bringing the catalyst and substrate into contact, and thereby to exercise increased control over the transformation. This has the potential to revolutionize synthetic organic chemistry.

This discovery puts a new tool in the hands of chemists. It proves that it is now possible to use different approaches to carry out molecular transformations, and it opens up entirely new perspectives to the world of synthetic chemistry. Professor Matile's group will now attempt to build molecules that are not accessible with conventional hydrogen bonds. This opens the door for the creation of new materials.

Media Contact

Stefan Matile
Stefan.Matile@unige.ch
41-223-796-523

 @UNIGEnews

http://www.unige.ch 

Stefan Matile | EurekAlert!

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>