These studies demonstrate that upon visible light excitation in the range of 400 to 500 nm, metal-to-ligand chargetransfer (MLCT) states with excess electron density on both the peripheral and bridging ligands are populated. However, the subsequent dynamics differs depending on the peripheral ligands. For the systems bearing fbpy and dceb, i.e., electron-deficient peripheral ligands (with respect to plain bpy), an equilibration between the states centered on the respective peripheral ligands and bridging unit occurs, resulting in a minor population of bridge-centered states. Conversely, for the catalysts bearing bpy or tbbpy (the latter being electron-rich compared to bpy), a significant portion of the excess electron density is shifted to the bridge within a few picoseconds. However, it was observed that the initial states that are localized on the peripheral ligands offer loss channels in parallel to the PS-to-CAT electron transfer. Consequently, the peripheral ligands can also influence photocatalysis, e.g., by providing decay pathways or function as reservoirs for excess electron density which may lead to the shift of electron density in an unfavorable direction for photocatalysis, i.e., towards the peripheral ligands instead of CAT unit. It has been postulated in the past that directed electron transfer from the photosensitizer to the catalytic center, i.e. only involving bridge-associated molecular orbitals, is beneficial for photocatalysis. In contrast, Vos et al. found that terpyridine-bridged Ru-Pt dyads exhibited increased photocatalytic activity when a long-lived MLCT state with excess electron density on the peripheral bipyridine-like ligands was formed. This was associated with the comparably short excited state lifetime of bridge centered MLCT states. These observations resulted from a systematic alteration of the electronic structure in the peripheral bipyridine-like ligands through 4,4'-substitution. However, to date, the impact of peripheral spectator ligands, facilitating unidirectional electron transfer, on photocatalytic properties has not been definitively explored in individual systems, specifically when only the auxiliary ligands were varied.