Coupling of photoactive transition metal complexes to a functional polymer matrix

Conductive polymers represent a promising alternative to semiconducting oxide electrodes typically used in dye‐sensitized cathodes as they more easily allow a tuning of the physicochemical properties. This can then also be very beneficial for using them in light‐driven catalysis. In this computational study, we address the coupling of Ru‐based photosensitizers to a polymer matrix by combining two different first‐principles electronic structure approaches. We use a periodic density functional theory code to properly account for the delocalized nature of the electronic states in the polymer. These ground state investigations are complemented by time‐dependent density functional theory simulations to assess the Franck‐Condon photophysics of the present photoactive hybrid material based on a molecular model system. Our results are consistent with recent experimental observations and allow to elucidate the light‐driven redox chemical processes – eventually leading to charge separation – in the present functional hybrid systems with potential application as photocathode materials. The integration of molecular light‐driven catalyst into a polymer matrix allows to tailor photochemical devices as the embedding can give control over charge transfer processes, photochemical reactivity and degradation resistance. Combining periodic and local quantum chemical approaches, we elucidate the electronic coupling between a polymer and a photosensitive complex, which is a prerequisite for a rational tailoring of such systems. Thus, we identify possible routes towards photoinduced excitations that could trigger catalytic reactions at metal centers attached to the photosensitizer.