Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Porphyrin electron-transfer reactions observed at the molecular level

06.08.2007
Researchers at Temple University have observed and documented electron transfer reactions on an electrode surface at the single molecule level for the first time, a discovery which could have future relevance to areas such as molecular electronics, electrochemistry, biology, catalysis, information storage, and solar energy conversion.

The researchers have published their findings, “Dynamics of Porphyrin Electron-Transfer Reactions at the Electrode–Electrolyte Interface at the Molecular Level,” in the international scientific journal, Angewandte Chemie (http://www3.interscience.wiley.com/cgi-bin/abstract/114287533/ABSTRACT).

“The simplest chemical reactions are oxidation and reduction,” says Eric Borguet, professor of chemistry at Temple and the study’s main author. “Chemistry is basically all about the transfer of electrons from one atom to another or one molecule to another. Those reactions are called ‘redox’ reactions.”

According to Borguet, one important place where these reactions occur is on an electrode surface. For example, metal corrosion is essentially oxidation. Corrosion can sometimes be reversed by reducing the oxides and reclaiming the metal.

... more about:
»Borguet »Molecule »Oxidation »electrode »oxidize

“Most of our studies of oxidation and reduction basically involve measuring the flow of electrons in and out of bulk chemical systems,” he says. “We’ve never really looked at this at the single molecule level, looking at it one molecule at a time. And it wasn’t necessarily clear that we could do that.”

As part of their research, Borguet and his collaborator were looking on a metal electrode surface at porphyrins, an important class of molecules that are involved in a number of biological processes, and in fact, can act as a catalyst for these processes.

The Temple researchers used scanning tunneling microscopy, in which a sharp metal tip scans the electrode surface and measures the passage of electrons from the tip, through the molecules, to the metal surface. They noted that the chemical state of the molecule changes the ability of the electrons to pass from the metal tip to the electrode.

“We noticed that some of these molecules, under certain conditions, appeared dark while others appeared bright,” noted Borguet. “What we essentially figured out was that the molecules change color and appear dark when we apply a potential to the electrode that begins to oxidize, or essentially pull out an electron from, the molecule. So now it seems that we can see the difference between oxidized molecules—the dark ones—and reduced molecules—the bright ones.”

Borguet says that by gaining a handle on the molecules’ chemical state, researchers now have the ability to identify oxidized and reduced molecules, and to track them individually.

“As researchers, we can now ask questions such as ‘Do molecules oxidize one at a time or do entire domains or areas on the surface oxidize together"’,” he says. “Do they oxidize in pairs or in clusters" If one molecule oxidizes, is it going to make the oxidation of a neighboring molecule more or less likely" What is the timescale under which these processes occur and what factors facilitate redox reactions"”

Borguet believes the Temple researchers are the first to observe and understand this interfacial electron transfer process at the single molecule level.

“We think if you look back in the literature and at other peoples’ data there is some evidence for this, but I don’t think they actually recognized that they were observing this process,” he says.

Preston M. Moretz | EurekAlert!
Further information:
http://www.temple.edu

Further reports about: Borguet Molecule Oxidation electrode oxidize

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>