Probing aurophilicity and solvation dynamics in stimuli-responsive Au-Au dimer complexes

We propose to investigate the formation of aurophilic bonds in solvated dinuclear Au(I) complexes upon electronic transition to the emissive excited state. Optical studies suggest the dependency on the solvent environment and counter ions [1-3] while the exact electronic and structural origins of enhanced aurophilicity remain unclear. By combining pump-probe wide-angle X-ray scattering (WAXS) and X-ray absorption spectroscopy (XAS) in solution we aim to visualize drastic changes in molecular structure and local redistribution of electron density upon charge transfer when the weak aurophilic bond is formed in the triplet excited state. Moreover, with the X-ray scattering method it will be possible to monitor rearrangements of solvent molecules around the excited solute and reveal the critical role of the environment affecting the aurophilicity.