Electrochemistry. Cyclic (CV) and differential pulse voltammetry (DPV) were performed in acetonitrile (for solubility reasons the CVs of phenPer are recorded in dichloromethane, see Fig. -10 and Tab. S1). The CV of Rh III phenPer shows a quasi-reversible oxidation wave (0.52 V vs. Fc 0/+ ) ascribed to the Per unit, which is presumably overlaid by an irreversible oxidation of the chloride-ions in solution. The Per-centered oxidation of phenPer is anodically shifted (0.60 V vs. Fc 0/+ ) compared to Rh III phenPer. At higher anodic potentials, irreversible oxidation of the perylene occurs for both the ligand phenPer and the complex Rh III phenPer. The individual reductions of Rh III phenPer are localized on the Rh-ion and the phen-and Per-moiety of the phenPer ligand. The CVs reveal two quasi-reversible (-1.19 and -2.06 V vs. Fc 0/+ ) and three irreversible (-2.52, -2.65 and -2.77 V vs. Fc 0/+ ) reduction peaks. The two-electron reduction of the Rh III/I couple at -1.19 V vs. Fc 0/+ is accompanied by a loss of the chlorido ligand ultimately forming [(phenPer)Rh I (Cp*)] (Rh I phenPer). The second reduction is associated with the phen-moiety (-2.06 V vs. Fc 0/+ ), which is anodically shifted compared to phenPer (-2.15 V vs. Fc 0/+ , see Fig. ) due to the coordination of the Rh I ion. At more cathodic potentials between -2.5 and -2.8 V vs. Fc 0/+ , the Per moiety is reduced irreversibly. Ground state absorption and emission properties. It is essential to understand the nature of the initially excited states to rationalize the photochemical processes underlying light-driven catalysis. Fig. shows the ground state absorption spectra of phenPer and Rh III phenPer in acetonitrile.