van der Veen, Renske M.Bressler, ChristianMilne, Chris J.Pham, Van-ThaiEl Nahhas, AmalLima, Frederico A.Gawelda, WojciechBorca, Camelia N.Abela, RafaelChergui, Majed2010-11-302010-11-302010-11-30200910.1088/1742-6596/190/1/012054https://infoscience.epfl.ch/handle/20.500.14299/59440WOS:000275152100055Describing the nature and structure of molecular excited states is important in order to understand their chemical reactivity and role as intermediates in photochemical reactions. The recent implementation of x-ray absorption spectroscopy in the ultrafast time domain allows studying the electronic and structural dynamics of photochemically active molecules in solutions. In this work we present the structural determination of a photoexcited diplatinum molecule, [Pt-2(P2O5H2)(4)](4-), which plays a photocatalytic role in important chemical conversions. A novel analysis of time-resolved EXAFS spectra based on the fitting of the experimental transients obtained from optical pump/x-ray probe experiments has been performed to derive a contraction of 0.31(5) angstrom of the two Pt atoms and a ligand expansion of 0.010(6) angstrom. The former is assigned to the formation of a transient Pt-Pt bond in the excited state, while the latter indicates a concomitant weakening of the Pt-ligand coordination bonds.Ray-Absorption SpectroscopyMolecular-StructuresLiquidstext::conference output::conference proceedings::conference paper