Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Researchers make flexible glass for tiny medical devices: Glass can bend over and over again on a nanoscale March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Imaging

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Discoveries

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Researchers make flexible glass for tiny medical devices: Glass can bend over and over again on a nanoscale March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Announcements

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Researchers make flexible glass for tiny medical devices: Glass can bend over and over again on a nanoscale March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

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

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Researchers make flexible glass for tiny medical devices: Glass can bend over and over again on a nanoscale March 27th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Tools

Researchers make flexible glass for tiny medical devices: Glass can bend over and over again on a nanoscale March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Caught on camera -- chemical reactions 'filmed' at the single-molecule level March 22nd, 2017

CRMGroup in Belgium uses a Deben three point bending stage in the development of new steel & coated steel products for automotive and other industrial applications March 21st, 2017

Military

Graphene sheets capture cells efficiently: New method could enable pinpoint diagnostics on individual blood cells March 3rd, 2017

Bioinspired process makes materials light, robust, programmable at nano- to macro-scale: Ultralight web of silk nano fibers withstands load 4,000 times its weight February 28th, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Engineers shrink microscope to dime-sized device February 17th, 2017

Photonics/Optics/Lasers

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Optical fingerprint can reveal pollutants in the air: Researchers at Chalmers University of Technology have proposed a new, sophisticated method of detecting molecules with sensors based on ultra-thin nanomaterials March 15th, 2017

MIPT physicists predict the existence of unusual optical composites March 10th, 2017

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