Using the capabilities of Science and Technology Facilities Council (STFC)’s ULTRA laser system, scientists from the University of Bristol in the UK have been able to watch a chemical reaction happening in solution with more detail than ever before. This could lead to improved drug design for medical therapies and catalysts for industrial processing, and pave the way for further applications in bio- and atmospheric chemistry. The results were published in Science Express on-line.
The ULTRA experiments, which took place at the Lasers for Science Facility (LSF) at STFC Rutherford Appleton Laboratory in Oxfordshire, will provide scientists with a unique insight into how liquid solvents affect chemical reactions at the molecular level. This can be in solution in liquids such as organic solvents or water. Organic solvents are used in the chemical and pharmaceutical industries for a wide range of industrial processes such as the manufacture of drug molecules for medical therapies. Similarly, much of the chemistry in the cells of living organisms takes place in solution so understanding these chemical reactions on such a fundamental level is vital.
Heading up the programme is Professor Andrew Orr-Ewing from the University of Bristol’s School of Chemistry who said: “We are very excited by the results - especially as 2011 is International Year of Chemistry. Liquids have a disordered and rapidly changing structure, and collisions between molecules occur on timescales as fast as ten thousand billion collisions per second. It is now possible for us to examine chemical reactions within a solvent at unprecedented levels of detail on picosecond timescales (one thousand-billionths of a second). We wouldn’t have been able to do this without the unique capability of the ULTRA laser”.
The knowledge gathered during these experiments will be used to better inform computer models designed to simulate chemical reactions in liquids.
The full paper can be found on the Science website: http://www.sciencemag.org/lookup/doi/10.1126/science.1197796
ULTRA provides ultrashort laser light pulses (each less than ten million millionths of a second long) of many colours that activate chemical reactions and then takes "snapshots" of the chemical reaction. Special cameras take 10,000 snapshots a second and each picture gives a "molecular fingerprint", a pattern unique to each type of molecule in the chemical mix. These fingerprints, known as vibrational spectra, (both infrared and Raman) not only give information on the changes in structure of the molecules but also show how fast and how efficiently these changes are happening.
The LSF is part of STFC’s world leading Central Laser Facility and is located in the new Research Complex at STFC’s Rutherford Appleton Laboratory.
The five year programme is funded by Engineering and Physical Science Research Council (EPSRC) and involves a collaboration between the School of Chemistry at the University of Bristol and the Lasers for Science Facility based at STFC’s Rutherford Appleton Laboratory in Oxfordshire.