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X-ray techniques have long been applied to chemical research, ranging from powder diffraction tools to analyse material structure to X-ray fluorescence measurements for sample composition. The development of high-brightness, accelerator-based X-ray sources has allowed chemists to use similar techniques but on more demanding samples and using more photon-hungry methods. X-ray Free Electron Lasers (XFELs) are the latest in the development of these large-scale user facilities, opening up new avenues of research and the possibility of more advanced applications for a range of research. The SwissFEL XFEL project at the Paul Scherrer Institute will begin user operation in the hard X-ray (2.1–12.4 keV) photon energy range in 2018 with soft X-ray (240–1930 eV) user operation to follow and here we will present the details of this project, it's operating capabilities, and some aspects of the experimental stations that will be particularly attractive for chemistry research. SwissFEL is a revolutionary new machine that will complement and extend the time-resolved chemistry efforts in the Swiss research community.

We review our recent studies of excited state structures and dynamics of chemical and biological systems with pico- and femtosecond X-ray absorption spectroscopy in the liquid phase.

We review our recent activity in the field of photo-induced structural dynamics in crystalline solids studied using femtosecond X-ray diffraction techniques.

We present the first structural determination of the Pt2(P2O5H2)44– anion in solution by analyzing the extended X-ray absorption fine structure (EXAFS) spectrum of the Pt LIII edge. The data could be fit with a simple model involving single and multiple scattering paths to near and far P-atoms, bridging O-atoms, and the other Pt-atom in the binuclear complex. A Pt–Pt distance of 2.876(28) Å and a Pt–P bond length of 2.32(4) Å are obtained. These values are in line with distances found in previous X-ray diffraction studies. The assignment of the EXAFS spectrum of the Pt2(P2O5H2)44– anion in its ground state is required for future time-resolved X-ray absorption measurements with the goal of determining the structure and dynamics of the complex in the 1,3A2u excited states.

The photoinduced energy and structural relaxation of aqueous iron(II)-tris-bipyridine ([FeII(bpy)3]2+), upon excitation into its singlet metal-to-ligand charge transfer (1MLCT) band, and the population of its short-lived (?0.6 ns) high-spin excited state have been characterized by combined ultrafast optical and X-ray spectroscopies. Polychromatic femtosecond fluorescence up-conversion reveals a very short lived 1MLCT emission band, which decays in ?20 fs by intersystem crossing to a 3MLCT, whose very weak emission is also observed. Transient absorption studies show that the latter decays in