Among the three photocatalysts, the benchmark tbppyRuPt performs best, as indicated by the turnover numbers (TONs) for hydrogen evolution from the sacrificial donor TEA of up to 400 (see green symbols in Figure ). For prbim-RuPt, in the same catalytic mixture, no hydrogen production was detected at all. This can be rationalized by the results of TA spectroscopy showing that upon irradiation only a comparatively short-lived MLCT phz state is formed. For prbimRuPt, these TA studies therefore agree with the catalytic inactivity of this photocatalyst from the photophysical perspective. For fbpyRuPt, however, the TA data are insufficient to explain the underlying trends. For example, the TA experiments reveal that the excess electron density persists on the fbpy ligand sphere after a first photon is absorbed. Nevertheless, the catalyst is active with respect to the reduction of protons, showing TONs of up to 277 after 68 hours (see purple symbols in Figure ). Similarly, catalytic activity has been observed in a Ru-Pt photocatalyst with electron-deficient peripheral dceb ligands by Vos and coworkers. This fact is also mirrored in the ESR experiments, revealing the population of phz-centered states under continuous illumination in the catalytic mixture (see purple line in Figure ) for fbpyRuPt. As previously shown for tbbpyRuPt, this can be tentatively rationalized by protoncoupled electron transfer processes inducing structural and electronic changes on the tpphz bridge to generate catalytically active intermediates. These findings underline that the first electron transfer, i.e., upon absorption of a first photon is essential to understand the overall functionality of the system, however, does not necessarily allow insights into the catalytic mechanism, where multiple electron transfer steps are involved and all steps are highly specific to the exact constitution of the system. Thus, so far, the effect of the peripheral ligands onto the catalytic electron transfer chain has been underestimated. As a result to the clear insights from our new spectator ligand prbim, we ascribe a critical steering function on the excited state to them.