Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Emory chemists reveal challenge to reaction theory


For nearly 75 years, transition-state theory has guided chemists in how they view the way chemical reactions proceed. Recent research by Emory University chemists is challenging the long-held theory, showing that in some cases chemical reactions can proceed via a path that completely bypasses the "transition state."

"Our understanding of chemical reactions rests on the notion of the transition state. If we think of reactions as occurring on an energy landscape, the transition state is the ’mountain pass’ separating the reactants, and the resulting products from the reaction are valleys," says Joel Bowman, an Emory theoretical chemist and chairman of the chemistry department.

According to transition state theory, reactions proceed over this mountain pass, Bowman says, "but our results for a well-studied chemical reaction show that the reaction occurs during the transition state -- and also through a surprising second path that is not near this transition state region."

Bowman’s research, done in collaboration with physical chemist Arthur Suits of Wayne State University in Detroit, was published in the Nov. 12 issue of the journal Science, and was highlighted in the Nov. 15 issue of Chemical and Engineering News.

Using high-powered computational work and detailed experimental studies, the scientists demonstrated that formaldehyde (H2CO) exposed to light rays (or photoexcited) can decompose to hydrogen and carbon monoxide via a path that skirts that reaction’s well-established transition state entirely.

Using detailed pictures and measurements developed by Suits, Bowman performed high-level calculations to create a "movie" of this second pathway. The visual model reveals that one of formaldehyde’s hydrogen atoms breaks off and roams around before bumping into the second hydrogen atom and forming a hydrogen molecule (H2). At no point in this second pathway does the reaction go through its transition state.

Formaldehyde decomposition has long been a model system for those studying transition-state theory because the reaction is simple enough to treat with high-level theoretical models, and the products are easily detectable. Bowman’s research shows that such transition-state-skirting pathways may not be all that unusual in other chemical reactions.

"Although this discovery does not overturn traditional transition-state theory, our work is part of a growing body of evidence that is changing and expanding the way chemists and biochemists think about chemical reactions," Bowman says.

Beverly Cox Clark | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht ‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie

nachricht Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>