Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


The hidden side of sulfur


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 | EurekAlert!

More articles from Life Sciences:

nachricht Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>