First ever peek at excited molecular orbitals in real time

Using powerful laser pulses and a special photoelectron detector, scientists in Germany have traced excited-state orbitals with femtosecond resolution for the first time. Until now, it was only possible to either map the spatial distribution of electrons in molecules or follow electron transfers in time during chemical reactions.

‘We measured the full momentum–space distribution of transiently excited electrons,’ says Frank Stefan Tautz from the Jülich Research Centre who led the study together with Ulrich Höfer from the University of Marburg. ‘This enables us to trace electron excitation pathways in the true, spatial sense of the word.’ Their work brings researchers one step closer to solving one of chemistry’s greatest challenges: being able to watch electrons move in a molecule in real time.