Featured Research

from universities, journals, and other organizations

Directly visualizing hydrogen bonds

Date:
July 15, 2014
Source:
American Institute of Physics (AIP)
Summary:
Using a newly developed, ultrafast femtosecond infrared light source, chemists have been able to directly visualize the coordinated vibrations between hydrogen-bonded molecules -- the first time this sort of chemical interaction, which is found in nature everywhere at the molecular level, has been directly visualized.

The hydrogen-bonding interaction causes the atoms on each individual N-methylacetamide molecule to vibrate in unison.
Credit: L. De Marco/UChicago

Using a newly developed, ultrafast femtosecond infrared light source, chemists at the University of Chicago have been able to directly visualize the coordinated vibrations between hydrogen-bonded molecules -- the first time this sort of chemical interaction, which is found in nature everywhere at the molecular level, has been directly visualized. They describe their experimental techniques and observations in The Journal of Chemical Physics, from AIP Publishing.

Related Articles


"These two-dimensional infrared spectroscopy techniques provide a new avenue to directly visualize both hydrogen bond partners," said Andrei Tokmakoff, the lab's primary investigator. "They have the spectral content and bandwidth to really interrogate huge parts of the vibrational spectrum of molecules. It's opened up the ability to look at how very different types of vibrations on different molecules interact with one another."

Tokmakoff and his colleagues sought to use two-dimensional infrared spectroscopy to directly characterize structural parameters such as intermolecular distances and hydrogen-bonding configurations, as this information can be encoded in intermolecular cross-peaks that spectroscopy detects between solute-solvent vibrations.

"You pluck on the bonds of one molecule and watch how it influences the other," Tokmakoff said. "In our experiment, you're basically plucking on both because they're so strongly bound."

Hydrogen bonds are typically perceived as the attractive force between the slightly negative and slightly positive ends of neutrally-charged molecules, such as water. While water stands apart with its unique polar properties, hydrogen bonds can form between a wide range of molecules containing electronegative atoms and range from weakly polar to nearly covalent in strength. Hydrogen bonding plays a key role in the action of large, biologically-relevant molecules and is often an important element in the discovery of new pharmaceuticals.

For their initial visualizations, Tokmakoff's group used N-methylacetamide, a molecule called a peptide that forms medium-strength hydrogen-bonded dimers in organic solution due to its polar nitrogen-hydrogen and carbon-oxygen tails. By using a targeted three-pulse sequence of mid-infrared light and apparatus described in their article, Tokmakoff's group was able to render the vibrational patterns of the two peptide units.

"All of the internal vibrations of hydrogen bonded molecules that we look at become intertwined, inextricably; you can't think of them as just a simple sum of two parts," Tokmakoff said.

Future work in Tokmakoff's group involves visualizing the dynamics and structure of water around biological molecules such as proteins and DNA.

"You can't just think of the water as sort of an amorphous solvent, you really have to at least on some level think of it atomistically and treat it that way," Tokmakoff said. "And if you believe that, it has huge consequences all over the place, particularly in biology, where so much computational biology ignores the fact that water has real structure and real quantum mechanical properties of its own."


Story Source:

The above story is based on materials provided by American Institute of Physics (AIP). Note: Materials may be edited for content and length.


Journal Reference:

  1. Luigi De Marco, Martin Thδmer, Mike Reppert and Andrei Tokmakoff. Direct observation of intermolecular interactions mediated by hydrogen bonding. The Journal of Chemical Physics, July 15, 2014 DOI: 10.1063/1.4885145

Cite This Page:

American Institute of Physics (AIP). "Directly visualizing hydrogen bonds." ScienceDaily. ScienceDaily, 15 July 2014. <www.sciencedaily.com/releases/2014/07/140715141755.htm>.
American Institute of Physics (AIP). (2014, July 15). Directly visualizing hydrogen bonds. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2014/07/140715141755.htm
American Institute of Physics (AIP). "Directly visualizing hydrogen bonds." ScienceDaily. www.sciencedaily.com/releases/2014/07/140715141755.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
3D Printed Cookies Just in Time for Christmas

3D Printed Cookies Just in Time for Christmas

Reuters - Innovations Video Online (Dec. 18, 2014) — A tech company in Spain have combined technology with cuisine to develop the 'Foodini', a 3D printer designed to print the perfect cookie for Santa. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
How Sony Hopes To Make Any Glasses 'Smart'

How Sony Hopes To Make Any Glasses 'Smart'

Newsy (Dec. 17, 2014) — Sony's glasses module attaches to the temples of various eye- and sunglasses to add a display and wireless connectivity. Video provided by Newsy
Powered by NewsLook.com
Los Angeles Police To Receive 7,000 Body Cameras

Los Angeles Police To Receive 7,000 Body Cameras

Newsy (Dec. 17, 2014) — Los Angeles Mayor Eric Garcetti announced the cameras will be distributed starting Jan. 1. Video provided by Newsy
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