Photochemical pathways for bond rearrangements and spin dynamics in azides

The photochemistry of energy-rich azides (R-N=N=N) shows a great diversity in organic synthesis and in the important field of click chemistry.

The nature of the populated excited state opens pathways to different reaction intermediates and the rate of formation of photoproducts can be detected in time-resolved experiments.

However, the precise determination of short-lived species and how they are formed often remains elusive and ambiguous.A broad spectrum of advanced quantum chemical calculations and molecular dynamics simulations in excited states and in solutions will be used to reach unprecedented mechanistic insight into non-adiabatic transitions between different reaction intermediates with varying spin states in solution.To be investigated:The photodissociation of aryl azide reactions, in which pathways to singlet and triplet nitrenes (R-N) and other reactive intermediates determine the yield of desired photoproducts.The photoinduced redox chemistry of metal-organic azides, which can be tweaked to synthesise biomimetic model systems containing high valence iron centres.The involvement of solvent degrees of freedom, influencing the electronic states and opening alternative pathways, will be investigated.Mechanistic insights into the photochemistry of azide compounds will enable controlled generation of reactive intermediates and photoproducts.

The aim is to facilitate rational design of selective photochemical synthesis, in industrial and pharmaceutical applications.