Making the molecular movie with atomic-scale spatial resolution and femtosecond/attosecond-scale time resolution

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We propose to develop and perform experiments aimed at retrieving the electronic structure and time dependent spatial configuration of molecules that undergo dynamics, making use of two newly available ultrashort XUV or X ray sources, namely high order harmonic generation (HHG) and free electron lasers (FEL). We aim to obtain information about the electronic and molecular structure with an unprecedented level of precision using electrons that are emitted through photoionization. When a high kinetic energy (typ. 100 to 300 eV) leaves a site within the molecule, it may scatter off one of the other nuclei or interfere with electrons emitted from equivalent sites in the molecule. Consequently the photoelectron angular distribution carries information about the relative position of the individual nuclei. The experiment will combine three forefront technologies, (i) ultrashort femtosecond and or attosecond XUV light sources, (ii) laser induced molecular alignment (to fix the molecular axis in space) and (iii) angle and kinetic energy resolved photoelectron spectroscopy. We plan to investigate the dissociation dynamics of CF3I, the isomerization dynamics of C2H4 and the isomer interconnection pathways and dynamics of 1,2diiodoethane and 4,4'diiodoazobenzene. Both the time evolution of the electronic configuration and the molecular structure will be monitored using the above mentioned XUV or X ray photoionization based electron diffraction measurements. We aim thereby to approach one of the Holy Grails in chemistry, i.e. to follow in time all aspects of a chemical reaction.