Exploring the reactivity of the excited radical cation with arenes. As expected from the experimental findings discussed above, no reactivity between benzene and the excited species of the neutral Ar 3 N have been detected. Interestingly, also no reaction between Ar 3 N •+ * and benzene (4.48 M) could be detected when exciting the system at either 395 or 740 nm (Figure ). However, considering that the overall efficiency of the coupling reaction is rather low, i.e. 16 h of illumination at high fluence was required for full conversion, the electron transfer from benzene to the excited state may represent the bottleneck of the reaction as eT from benzene to excited A or B may be simply too inefficient. Thus, as a proof of concept, we changed to 1,2-dimethoxy benzene as a substrate with a much lower redox potential. As seen in Figure , in presence of 1,2-dimethoxybenzene the excited A •+ * is significantly quenched forming a new species with an absorption spectrum peaking at ca. 505 nm. To note, this reaction occurs irrespective of the excitation wavelength (see Figure ). Accordingly, the differences in the coupling reaction efficiencies with either exciting at 400 nm or at 700 nm presented above, thus, can be simply explained by the significant different fluences of the two excitation sources. Repeating the C-N coupling model reaction exciting the electrochemically formed Ar 3 N •+ * at 645 nm and performing high resolution mass spectrometry, indeed trace amounts of the coupling product could be detected (see Figure ). And when using 1,4-dimethoxybenzene as substrate even a significant amount of the corresponding product was identified (see Figure ) giving further evidence that the excitation into higher lying excited states is not required for productive conversion and the discrepancies in efficiencies are only due to dramatic different photo fluxes used in the experiments. Furthermore, this also demonstrates that an involvement of electronic states with higher multiplicity can be ruled out since these are energetically not accessible.