Charting Molecular Dynamics with Ultrafast X-ray Techniques

This dissertation investigates and discusses the structural and photophysical properties of the bi-metallic d8d8 transition metal complexes IrDimen and PtPOP, and their tri-metallic derivatives AgPtPOP, TlPtPOP and AgIrDimen using Time-Resolved X-ray Solution Scattering (TR-XSS).
This work has two main focuses. Firstly, the analysis and comparison of a broad range of experiments investigating the molecular structures and photophysical properties of the bi-metallic complexes. These experiments were conducted at the European Synchrotron Radiation Facility (ESRF), with a X-ray pulse length of ∼100 picoseconds, and the Linac coherent light source (LCLS) free electron laser, with an X-ray pulse length of ∼30 femtoseconds. The high energy X-ray pulses accessible at the synchrotron are utilized for ultra-fine structural refinement of IrDimen alongside an investigation of the structural implications of the intersystem crossing in this system. The femtosecond resolution of the Free Electron Laser (FEL) is used to investigate excitation wavelength dependent structural dynamics of PtPOP and IrDimen as well as structural parameter distribution in an ensemble of excited state molecules following photoexcitation. Secondly, this work investigates the formation as well as the molecular and electronic structures of tri-metallic complexes, alongside their structural dynamics and dissociation reactions on the femtosecond timescale.