Nav: Home

How solvent molecules cooperate in reactions

October 06, 2016

Molecules from the solvent environment that at first glance seem to be uninvolved can be essential for chemical reactions. This has been shown by researchers studying the formation of an ether in pure solvents and in their mixtures. They explained the underlying mechanisms in detail using advanced spectroscopic and theoretical techniques. The conclusion: even solvent molecules that do not participate directly in the reaction are essential for the reaction process and can significantly influence reaction partners.

The results were described by a team of experimental and theoretical chemists from Ruhr-Universität Bochum, the University of Würzburg and the Max-Planck Institut für Kohlenforschung in Mülheim an der Ruhr in the journal Nature Communications.

Reactivity switched on by light

A flash of light can turn a rather inert chemical precursor into a highly reactive molecule, which itself reacts with surrounding solvent molecules. This can happen in less than a billionth of a second. One example is the molecule diphenylcarbene: it reacts quickly to an ether when methanol is the solvent. However, this reaction is not possible with the solvent acetonitrile.

The researchers led by Dr Elsa Sanchez-Garcia and Prof Dr Patrick Nürnberger investigated what happens when diphenylcarbene is present in a solvent mixture of methanol and acetonitrile. The formation of the ether takes place more slowly than in pure methanol; the yield is also smaller. In the current study, the researchers showed why.

Second solvent molecule crucial

One potential explanation could be that in the solvent mixture diphenylcarbene has to wait longer until a methanol molecule is close-by in order to react with it. "However, the reaction is not as simple as assumed at first glance," says Patrick Nürnberger from the Bochum Chair for Physical Chemistry II. "There are several mechanisms at work."

Although it would seem that only a single methanol molecule is required for the formation of the final ether molecule, the reaction only occurs when a second methanol molecule is present. This finding was the result of a combination of ultrafast spectroscopic experiments in the femtosecond range and multiscale molecular dynamics simulations.

Not just bystanders

The chemists describe in detail the reaction mechanisms for two scenarios: in one, diphenylcarbene first meets a single methanol molecule and then another is added later. In the second scenario, diphenylcarbene directly meets a compound of methanol molecules.

In both cases, it is shown that a single methanol molecule is not sufficient to trigger the reaction. "The other methanol molecules are thus not just bystanders, but rather assistants in the reaction," summarizes Nürnberger. "The results are an important part of understanding the interaction of reactive substances with the solvent environment."
-end-


Ruhr-University Bochum

Related Chemical Reactions Articles:

Caught on camera -- chemical reactions 'filmed' at the single-molecule level
Scientists have succeeded in 'filming' inter-molecular chemical reactions -- using the electron beam of a transmission electron microscope as a stop-frame imaging tool.
Study: Some catalysts contribute their own oxygen for reactions
New MIT research shows that metal-oxide catalysts can sometimes release oxygen from within their structure, enhancing chemical activity.
Chemists uncover a means to control catalytic reactions
Scientists at the University of Toronto have found a way to make catalysis more selective, breaking one chemical bond 100 times faster than another.
Deep insights from surface reactions
Using the Stampede supercomputer at the Texas Advanced Computing Center, researchers have developed biosensors that can speed up drug development, designed improved materials for desalinization, and explored new ways of generating energy from bacteria.
Scientists trace 'poisoning' in chemical reactions to the atomic scale
A combination of experiments, including X-ray studies at Berkeley Lab, revealed new details about pesky deposits that can stop chemical reactions vital to fuel production and other processes.
How solvent molecules cooperate in reactions
Molecules from the solvent environment that at first glance seem to be uninvolved can be essential for chemical reactions.
Scientists rev up speed of bionic enzyme reactions
Bionic enzymes got a needed boost in speed thanks to new research at the Berkeley Lab.
Adverse drug reactions may be under-reported in young children
A new study reveals that adverse drug reactions in newborns and infants may be under-reported.
New model predicts once-mysterious chemical reactions
A team of researchers from Los Alamos National Laboratory and Curtin University in Australia developed a theoretical model to forecast the fundamental chemical reactions involving molecular hydrogen.
Syracuse University chemists add color to chemical reactions
Members of the Maye Research Group at Syracuse University have designed a nanomaterial that changes color when it interacts with ions and other small molecules during a chemical reaction.

Related Chemical Reactions Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".