Ultrafast optical and X-ray studies of the dynamics of chemical systems

The advent of femtosecond (1 fs=10-15 s) laser technology some twenty-five years ago opened a whole new era in Science by its ability to probe in "real-time" nuclear motion in molecules, crystals, liquids and proteins. In the past fifteen years, huge efforts have been deployed aimed at combining the high time resolution of fs lasers with the high spatial resolutions of structural techniques, such as X-ray and electron diffraction and X-ray spectroscopies. In this talk, I will demonstrate the power of ultrafast spectroscopy from the visible to the X-ray range to monitor the electronic, spin and structural dynamics of chemical and biological systems and of solid materials. Examples will include the correlated spin and structural dynamics in hemoproteins and transition metal complexes, and the charge carrier dynamics in transition metal oxides.