Ultrafast dynamics of photoinduced processes in coordination compounds

This Chapter briefly introduces modern and emerging methods to study ultrafast processes in coordination compounds, which are key to any photon-driven application from artificial photosynthesis to information storage. Ultrafast optical methods [namely electronic transient absorption, fluorescence upconversion, time-resolved infrared and resonance Raman], structural methods [X-ray spectroscopies and scattering], and ultrafast multidimensional methods are discussed. The relevance of each method to photochemistry of coordination compounds is illustrated on specific examples. The importance of using multiple methods—e.g., combining electronic, vibrational, and X-ray spectroscopies—to resolve the complex and entangled electronic, structural and spin dynamics happening on the short, fs–ps timescales, is emphasized. Finally, the approaches to direct and control photochemical dynamics are discussed.