Featured Research

from universities, journals, and other organizations

New low-temperature chemical reaction explained

Date:
September 4, 2013
Source:
Massachusetts Institute of Technology
Summary:
Unusual reaction, never fully understood, is important to fuel combustion, atmospheric chemistry and biochemistry. In all the centuries that humans have studied chemical reactions, just 36 basic types of reactions have been found. Now, a 37th type of reaction can be added to the list.

Diagram illustrates the newly-discovered reaction that transforms molecules of ketohydroperoxide into acids and carbonyl molecules, after going through intermediate stages.
Credit: Illustration courtesy of Jalan et al

In all the centuries that humans have studied chemical reactions, just 36 basic types of reactions have been found. Now, thanks to the work of researchers at MIT and the University of Minnesota, a 37th type of reaction can be added to the list.

Related Articles


The newly explained reaction -- whose basic outlines had been known for three decades, but whose workings had never been understood in detail -- is an important part of atmospheric reactions that lead to the formation of climate-affecting aerosols; biochemical reactions that may be important for human physiology; and combustion reactions in engines.

The new analysis is explained in a paper by MIT graduate student Amrit Jalan, chemical engineering professor William Green, and six other researchers, published in the Journal of the American Chemical Society.

Stephen Klippenstein, a senior scientist at the Argonne National Laboratory in Illinois who was not involved in this research, says, "I think this may be the best paper I have read this year. It uses a multitude of theoretical methods … to explore multiple aspects of a novel discovery that has important ramifications in atmospheric chemistry, combustion kinetics and biology."

The reaction's details sound esoteric: a low-temperature oxidation that results in the decomposition of complex organic molecules known as gamma-ketohydroperoxides. When he first described the reaction in the scientific literature 30 years ago, Stefan Korcek of the Ford Motor Company proposed a hypothesis for how the reaction might take place. The new work shows that Korcek had the right concept, although some details differ from his predictions.

The original discovery was the result of analyzing how engine oils break down through oxidation -- part of an attempt to produce oils that would last longer. That's important, Green points out, since waste oil is among the largest hazardous waste streams in the United States.

In analyzing the problem, Korcek realized that "there were fundamental things about the way even simple hydrocarbons react with oxygen that we didn't understand," Green says. By examining the products of the reaction, which included carboxylic acids and ketones, Korcek outlined an unusually complex multipart reaction. But for the next three decades, nobody found a way to verify whether the reaction or the steps he outlined could work.

Jalan says that the MIT researchers' analysis came about almost by accident. "I was looking at that paper for a different study," he says, "and I came across [Korcek's] work, which hadn't been verified either theoretically or experimentally. … [We] decided to see if we could explain his observations by throwing quantum mechanical tools at the problem."

In collaboration with the Minnesota researchers -- including Donald Truhlar, a co-author of the new paper and a leading expert in such calculations -- Jalan and Green were able to demonstrate exactly why the reaction works as it does. But they also found that part of the process must differ slightly from Korcek's original hypothesis.

Green says that understanding how this "very important reaction" works could be significant in several fields. The researchers' initial impetus was, in part, a colleague's exploration of biofuel combustion. The new understanding of the degradation that can take place as different fuels oxidize -- sometimes producing toxic or corrosive byproducts -- could help narrow the choice of fuel types to pursue, he says.

The process is also related to oxidations that take place in the body, contributing to the tissue damage and aging that antioxidant vitamins seek to combat, Green says.

Green points out that because this is an entirely new type of reaction, it opens the door to research on other variations. "Once you discover a new type of reaction, there must be many similar ones," he says.

"It's very odd to have so many reactions at once in such a small molecule," Green adds. "Now that we know that can happen, we're searching for other cases."

Anthony Dean, dean of the College of Applied Science and Engineering at the Colorado School of Mines, who was not involved in this work, says, "A particularly nice aspect of this work is to then consider how this finding might be applicable to other systems. In a broader context, this combined effort by two very prominent research groups illustrates the power and potential for electronic structure calculations [in] quantitatively important problems in chemical kinetics."

Klippenstein adds, "As a result of this clear exposition and the high level of theory that was applied, I believe this work will be widely accepted immediately. I certainly am already convinced by their conclusions."

The research was supported in part by the U.S. Department of Energy, and used computing facilities at the Pacific Northwest National Laboratory and the Minnesota Supercomputing Institute.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by David L. Chandler. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amrit Jalan, Ionut M. Alecu, Rubén Meana-Pañeda, Jorge Aguilera-Iparraguirre, Ke R. Yang, Shamel S. Merchant, Donald G. Truhlar, William H. Green. New Pathways for Formation of Acids and Carbonyl Products in Low-Temperature Oxidation: The Korcek Decomposition of γ-Ketohydroperoxides. Journal of the American Chemical Society, 2013; 135 (30): 11100 DOI: 10.1021/ja4034439

Cite This Page:

Massachusetts Institute of Technology. "New low-temperature chemical reaction explained." ScienceDaily. ScienceDaily, 4 September 2013. <www.sciencedaily.com/releases/2013/09/130904130343.htm>.
Massachusetts Institute of Technology. (2013, September 4). New low-temperature chemical reaction explained. ScienceDaily. Retrieved April 24, 2015 from www.sciencedaily.com/releases/2013/09/130904130343.htm
Massachusetts Institute of Technology. "New low-temperature chemical reaction explained." ScienceDaily. www.sciencedaily.com/releases/2013/09/130904130343.htm (accessed April 24, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, April 24, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Food Printing: The Meal of the Future?

3D Food Printing: The Meal of the Future?

AP (Apr. 23, 2015) — Developers of 3D food printing hope the culinary technology will revolutionize the way we cook and eat. (April 23) Video provided by AP
Powered by NewsLook.com
'Safest Bike Ever' Devised by British Entrepreneur

'Safest Bike Ever' Devised by British Entrepreneur

Reuters - Innovations Video Online (Apr. 23, 2015) — A British inventor says his Babel bike is the safest bicycle ever produced. Crispin Sinclair - son of famous British inventor Sir Clive Sinclair - hopes the bike&apos;s safety cage, double seatbelt, and host of other measures will inspire non-cyclists to get in the saddle. Jim Drury went to see it in action. Video provided by Reuters
Powered by NewsLook.com
First Successful Aerial Refueling of a Drone

First Successful Aerial Refueling of a Drone

Reuters - Innovations Video Online (Apr. 23, 2015) — The bat-wing U.S. Navy drone that became the first autonomous airplane to take off and land on an aircraft carrier accomplished yet another milestone on Wednesday, becoming the first unmanned aircraft to undergo aerial refueling. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Human or Robot You Decide

Human or Robot You Decide

Reuters - Business Video Online (Apr. 23, 2015) — An ultra-realistic humanoid robot called &apos;Han&apos; recognises and interprets people&apos;s facial expressions and can even hold simple conversations. Developers Hanson Robotics hope androids like Han could have uses in hospitality and health care industries where face-to-face communication is vital. Matthew Stock reports. Video provided by Reuters
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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