1. Department of Chemistry, Bowdoin College, Brunswick, Maine 04011, United States
2. J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
3. University of Chemistry and Technology, Prague, Technická 5, CZ-166 28 Prague, Czech Republic
4. Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0FA, U.K.
5. Beckman Institute, California Institute of Technology, Pasadena, California 91125, United States
6. Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London E1 4NS, United Kingdom