UCL News


Marlow Medal goes to Dr Stefan Willitsch

6 March 2008


stefan rsc.org/" target="_self">Royal Society of Chemistry
  • Dr Stefan Willitsch
  • This year's Royal Society of Chemistry Marlow Medal and Prize has been awarded to Dr Stefan Willitsch (UCL Chemistry) for his pioneering work in cold ion-molecule chemistry.

    'Cold chemistry' is a relatively new branch of the discipline in which chemical reactions are studied at extremely low temperatures - lower than 1 Kelvin. At such low temperatures, quantum-mechanical effects become particularly important and strongly influence the chemical reactivity. 

    Dr Willitsch, together with his former colleague at the University of Oxford, Professor Timothy Softley, are the first scientists to develop the technique: "We have developed a new experiment to study chemical reactions between cold ions and cold neutral molecules. At the low temperatures achieved in our setup, the ions form an ordered state known as a "Coulomb crystal" in which it is possible to observe and manipulate single particles. Our setup represents the first apparatus in which two different methods for the production of cold molecules have been combined to study chemical reactions."

    This new technique is already enabling Dr Willitsch to conduct studies which otherwise would have been impossible: "With this technique, we recently investigated the reaction of cold calcium ions with cold fluoromethane molecules down to temperatures of about one Kelvin. Because of the exceptional sensitivity that can be achieved using the Coulomb crystal technology, we were able to study cold reactive collisions between neutral molecules and ions at the single-particle level."

    The implications of the new science are far-reaching, as Dr Willitsch explains:
    "The low temperature regime represents an ideal environment to study quantum mechanical details of chemical reactions in order to gain a better understanding of the physical phenomena that underlie chemical reactivity."

    The Marlow Medal and Prize is awarded each year to a physicist under the age of 34 for the "most meritorious contribution to physical chemistry or chemical physics". To find out more about the Royal Society of Chemistry and Dr Willitsch's research, use the links at the top of this article.