Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Rice technique expands options for molecular imaging: One-of-a-kind spectrometer reads vibrations between atoms to find structures of molecules

A technique by Rice University chemist Junrong Zheng measures vibrations between atoms to determine the three-dimensional form of molecules.Credit: Zheng Lab/Rice University
A technique by Rice University chemist Junrong Zheng measures vibrations between atoms to determine the three-dimensional form of molecules.

Credit: Zheng Lab/Rice University

Abstract:
-- A Rice University laboratory has improved upon its ability to determine molecular structures in three dimensions in ways that challenge long-used standards.

Rice technique expands options for molecular imaging: One-of-a-kind spectrometer reads vibrations between atoms to find structures of molecules

Houston, TX | Posted on August 15th, 2013

By measuring the vibrations between atoms using femtosecond-long laser pulses, the Rice lab of chemist Junrong Zheng is able to discern the positions of atoms within molecules without the restrictions imposed by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) imaging.

The technique can capture the structure of molecules at room temperature or very low or high temperatures and in many kinds of samples, including crystals, powders, gels, liquids and gases. It will be useful to scientists who study catalysis, energy storage, organic solar cells and biomembranes, among many other possibilities, Zheng said.

The researchers reported their results online this week in the American Chemical Society's Journal of Physical Chemistry.

Zheng and his co-authors at Rice and Oak Ridge National Laboratory analyzed variations of a model molecule, 4'-methyl-2'nitroacetanilide (MNA), and compared the results with computer-generated and XRD models. The images matched nicely, he said.

Traditional spectrometers read the wavelengths of light scattered by samples to identify materials and study their properties. But the one-of-a-kind spectrometer developed by Zheng uses very short laser pulses to read the vibrational energies inherent to every atom. Those energies determine how atoms bond to form a molecule, and a measurement of the length and angles of those bonds can be extracted from the vibrations themselves, he said.

The infrared and terahertz lasers used for the experiment captured information about a molecular angle in a mere 100 femtoseconds. (One femtosecond is a millionth of a billionth of a second.)

"The important part of this paper is to demonstrate that our method can determine three-dimensional molecular structures no matter whether they're in liquids or solids," Zheng said.

"Typically, when organic chemists synthesize a molecule, they know its makeup but have no idea what the structure is," he said. "Their first option is to make a single crystal of the molecule and use XRD to determine the precise structure. But in many cases it's very tedious, if not impossible, to grow a single crystal.

"People also use NMR to learn the structure," he said. "But the trouble with many molecules is the solubility is really bad. Insoluble molecules can't be read well by either method."

The Rice technique, dubbed "multiple-dimensional vibrational spectroscopy," is able to capture the conformation of small molecules -- for starters -- with great accuracy, Zheng said. The spectrometer reads only intramolecular interactions among vibrations and ignores interactions between molecules, he said.

"The atoms in every molecule are always vibrating, and each bond between atoms vibrates at a certain frequency, and in a certain direction," he said. "We found that if we can measure the direction of one vibration and then another, then we can know the angle between these two vibrations - and therefore the angle between the bonds."

He said the researchers begin with the chemical formula and already know, through Fourier transform infrared spectroscopy, how many vibrational frequencies are contained in a given molecule. "Then we measure each vibrational mode, one by one. Once we get all the cross-angles, we can translate this to a model," he said.

For now, as a proof of concept, Zheng and his team analyze molecules for which the structure is already known. Over time, the technique should be able to analyze much larger molecules, like viruses that contain thousands or tens of thousands of atoms, he said.

"This is just the first demonstration that this method works," he said. "These are simple molecules, 23 or 24 atoms. I think it will take some time to get to proteins. My expectation is that it will take 10 to 20 years to develop. Remember, for NMR, it took 50 years to be able to read the structure of proteins."

Hailong Chen, a Welch postdoctoral research fellow at Rice, is lead author of the paper; Co-authors are Rice graduate students Yufan Zhang and Jiebo Li and Oak Ridge researchers Hongjun Liu and De-en Jiang. Zheng is an assistant professor of chemistry.

The Air Force Office of Scientific Research, the Welch Foundation, the Packard Foundation and the Department of Energy supported the research.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,708 undergraduates and 2,374 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to tinyurl.com/AboutRiceU.

Follow Rice News and Media Relations via Twitter @RiceUNews.

For more information, please click here

Contacts:
David Ruth
713-348-6327


Jade Boyd
713-348-6778

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Zheng Lab:

Related News Press

News and information

New ASTM Standards Will Help Educate Present and Future Nanotechnology Workforces April 26th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

QD Vision Wins 2015 Bronze Edison Award for Color IQ™ Quantum Dot Technology April 26th, 2015

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Imaging

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

A silver lining: UCSB researchers cradle silver nanoclusters inside synthetic DNA to create a programmed, tunable fluorescent array April 23rd, 2015

Richards-Kortum elected to American Academy of Arts and Sciences: April 22nd, 2015

Govt.-Legislation/Regulation/Funding/Policy

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Electron spin brings order to high entropy alloys April 23rd, 2015

Discoveries

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Announcements

New ASTM Standards Will Help Educate Present and Future Nanotechnology Workforces April 26th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

QD Vision Wins 2015 Bronze Edison Award for Color IQ™ Quantum Dot Technology April 26th, 2015

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Tools

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Quantum 'paparazzi' film photons in the act of pairing up April 22nd, 2015

Richards-Kortum elected to American Academy of Arts and Sciences: April 22nd, 2015

Military

Electron spin brings order to high entropy alloys April 23rd, 2015

Engineer improves rechargeable batteries with MoS2 nano 'sandwich' April 18th, 2015

Cobalt film a clean-fuel find: Rice University discovery is efficient, robust at drawing hydrogen and oxygen from water April 15th, 2015

MIT sensor detects spoiled meat: Tiny device could be incorporated into 'smart packaging' to improve food safety April 15th, 2015

Photonics/Optics/Lasers

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Quantum 'paparazzi' film photons in the act of pairing up April 22nd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project