Featured Research

from universities, journals, and other organizations

Porphyrin Electron-transfer Reactions Observed At The Molecular Level

Date:
August 6, 2007
Source:
Temple University
Summary:
Researchers 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.

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 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.

"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.

The researchers have published their findings, "Dynamics of Porphyrin Electron-Transfer Reactions at the Electrode--Electrolyte Interface at the Molecular Level," in the journal, Angewandte Chemie. The research was funded with support from the National Science Foundation.


Story Source:

The above story is based on materials provided by Temple University. Note: Materials may be edited for content and length.


Cite This Page:

Temple University. "Porphyrin Electron-transfer Reactions Observed At The Molecular Level." ScienceDaily. ScienceDaily, 6 August 2007. <www.sciencedaily.com/releases/2007/08/070802105907.htm>.
Temple University. (2007, August 6). Porphyrin Electron-transfer Reactions Observed At The Molecular Level. ScienceDaily. Retrieved August 2, 2014 from www.sciencedaily.com/releases/2007/08/070802105907.htm
Temple University. "Porphyrin Electron-transfer Reactions Observed At The Molecular Level." ScienceDaily. www.sciencedaily.com/releases/2007/08/070802105907.htm (accessed August 2, 2014).

Share This




More Matter & Energy News

Saturday, August 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Newsy (July 31, 2014) The deal will help build a massive battery factory that Tesla says will produce 500,000 lithium batteries by 2020. Video provided by Newsy
Powered by NewsLook.com
Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Cycle World (July 30, 2014) The Bonnier Motorcycle Group presents Smoked; a three part video series. In this episode the 2015 Ducati Diavel takes on the 2014 Chevy Corvette Stingray Video provided by Cycle World
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins