Subscribe free to our newsletters via your
. Space Industry and Business News .

A Molecular Ballet under the X-ray Laser
by Staff Writers
Hamburg, Germany (SPX) Mar 06, 2014

The molecules (green stream) enter the test chamber with random orientation and are forced to all take up the same pose by an optical laser (red). A bright X-ray flash (blue) produces a diffraction image (upper right) that contains structural information about the molecule. Image courtesy Stephan Stern/CFEL. For a larger version of this image please go here.

An international team of researchers has used the world's most powerful X-ray laser to take snapshots of free molecules. The research team headed by Prof. Jochen Kupper of the Hamburg Center for Free-Electron Laser Science (CFEL) choreographed a kind of molecular ballet in the X-ray beam.

With this work, the researchers have cleared important hurdles on the way to X-ray images of individual molecules, as they explain in the scientific journal Physical Review Letters. CFEL is a cooperation of DESY, the University of Hamburg, and the Max Planck Society.

"We have captured the first images of an ensemble of isolated molecules with an X-ray laser," said DESY scientist Kupper, who is also a professor at the University of Hamburg and a member of the Hamburg Centre for Ultrafast Imaging (CUI) cluster of excellence.

"The molecules all posed for the picture in synch." According to Kupper, this approach opens the way for studies of the ultra-fast dynamics of isolated molecules. There are existing techniques to image single molecules, but none of these is fast enough to catch the ultra-fast motion of molecules.

The conventional way to determine the atomic structure of molecules is to "freeze" them in a crystal and illuminate them with bright X-rays. However, many molecules are extremely difficult to crystallise. In particular, this is a problem with many biomolecules.

What's more, molecules in a crystal can have different properties than molecules in their free form. And molecular dynamics can only be studied to a very limited extent in the crystalline state. Yet exactly this information is in great demand in chemistry, physics, materials research and life sciences. Researchers are therefore working on methods for taking snapshots of individual free molecules.

"The molecules we are investigating are some of the smallest structures in chemistry and biology and consist of just a handful of atoms," emphasised co-author Dr. Stephan Stern of CFEL. "In order to observe them, you need the most powerful X-ray source on earth, with the shortest exposure time - one ten-trillionth of a second."

The researchers therefore used what is currently the most powerful X-ray laser, the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory in California. This free electron laser (FEL) generates short-wave X-ray light by using powerful magnets to send fast electrons from a particle accelerator along a tightly defined slalom course.

In every curve, the fast particles emit flashes of light which add up to an intense laser pulse. These X-ray pulses have such a short wavelength that they can make even atomic dimensions visible. They are also so short and so bright that they can be used to freeze the ultra-fast motion of molecules. But not even this bright light is currently capable of making clear images of single molecules.

That's why the researchers use a trick to study the molecules - they measure how strongly the X-ray light is scattered by the molecules. The molecular structure can be calculated from this diffraction pattern. The more molecules contribute to the diffraction pattern - for example, in a crystal - the clearer it will be.

Instead of a crystal, Kupper's team illuminated an ensemble of around 100 individual molecules for every single image. However, these molecules must all have the same orientation, so that their diffraction patterns add up and amplify one another. The team took a simple molecule - consisting of a benzene ring with a small nitrile arm of carbon and nitrogen and with two iodine atoms attached, one above and one below.

The researchers first sorted the compound - known chemically as di-iodobenzonitrile - using an inhomogeneous electric field, so that only molecules in the same quantum state could wander into the X-ray beam. They then used a special arrangement of lasers to ensure that the particles all took up the same pose for the photo - like the members of a ballet ensemble - so that all of the benzene rings had the two iodine atoms aligned at their top and bottom.

"We sorted the molecules, led them onto the stage, and then got them to pose in synch for the photo," said Stern. "Then we took the picture with an ultra-short flash of incredible brightness. The exposure time was so short that the superfast motion of the molecules was frozen and we were able to capture a sharp image of the tiny structures." In this way, the researchers were able to determine that the distance between the two iodine atoms on the benzene ring was 800 picometres (800 billionths of a millimetre), which is in good agreement with the actual value of 700 picometres known from theory.

The experiments thus point the way to the investigation of extremely high-speed molecular dynamics, in particular at the European X-Ray Laser XFEL, which is currently being constructed from the DESY site in Hamburg's Bahrenfeld district to the neighbouring town of Schenefeld in Schleswig-Holstein. "In future, we will be able to get the molecules to carry out predetermined sequences of movements, like all of them waving their arms", said Kupper.

"We will be able to film these movements by repeating the experiment a large number of times, taking the snapshots at slightly different times and putting the resulting pictures together in a film. Just like a super slow-motion shot in a sports event or a documentary, these films will show the exact sequence of movements of the molecules during chemical reactions with a precision and level of detail that have never before been achieved."

Researchers from Germany, Denmark, the Netherlands, Sweden and the USA participated in the study; "X-ray diffraction from isolated and strongly aligned gas-phase molecules with a free-electron laser"; J. Kupper, S. Stern, H. N. Chapman, et al.; Physical Review Letters, 2014; DOI: 10.1103/PhysRevLett.112.083002


Related Links
Deutsches Elektronen-Synchrotron
Space Technology News - Applications and Research

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Diagnosis just a breath away with new laser
Adelaide, Australia (SPX) Feb 12, 2014
University of Adelaide physics researchers have developed a new type of laser that will enable exciting new advances in areas as diverse as breath analysis for disease diagnosis and remote sensing of critical greenhouse gases. Published in the journal Optics Letters, the researchers from the University's Institute for Photonics and Advanced Sensing and the School of Chemistry and Physics d ... read more

ADS builds 'space furnace' to test materials of the future on the ISS

New Record Set for Data-Transfer Speeds

Ecliptic RocketCam Captures Sirius Antenna Deployment In Geo Orbit

3-D printer creates transformative device for heart treatment

ASC Signal Completes First Phase of Horizon Teleports Installation and Receives Additional Antenna Order

Soldier's Network Update: US Army Capability Set 14 to Include AN/PRC-155 Manpack Tactical Radios

New Wireless Tagging And Tracking Capability For Managing Sensitive Assets

Lockheed Martin Mobile "Network in a Box" Upgraded

Payload prep continues for Arianespace Soyuz for Sentinel-1A

Russia to Start Building New Manned Rocket Launch Pad in 2015

New Vostochny space center a key priority for Russian Far East

'Mission of Firsts' Showcased New Range-Safety Technology at NASA Wallops

McMurdo Announces Global Availability of Maritime Fleet Management Software

Fifth Boeing GPS IIF Spacecraft Sends Initial Signals from Space

Russia to deploy up to 7 Glonass ground stations outside of national territory in 2014

Northrop Grumman Awarded U.S. Military Contract for Navigation Systems

Boeing Maritime Surveillance Aircraft Demonstrator Completes First Flight

Raytheon and PASSUR to provide improved airspace and airport efficiency

Improvement in polymers for aviation

ARES Aims to Provide More Front-line Units with Mission-tailored VTOL Capabilities

Tiny, Cheap, Foolproof: Seeking New Component to Counter Counterfeit Electronics

A cavity that you want

Taiwan's TSMC making chips for new iPhone: report

D-Wave chip passes rigorous quantum-ness tests

Satellite Sees Winter Storm March Over Mid-Atlantic

NASA-JAXA Launch Mission to Measure Global Rain, Snow

NASA Building Four Spacecraft to Study Magnetic Reconnection

Counting Down to GPM

Maize Plus Bacteria: One-Two Punch Knocks Copper Out of Stamp Sand

China promises cleaner air, steady 7.5 percent growth

China's premier 'declares war' on pollution

Reforms slow in Bangladesh's toxic tanneries

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.