The combination of the RAE and the amine donor, DABCO, results in EDA complex formation, producing a distinct charge transfer band absorption band. This absorption band tails into the visible range, allowing absorption at 450 nm and consequent photolysis of the RAE (Fig. ). In contrast, the individual reagents show only negligible absorbance in the visible region (Fig. and Supplementary Section 5.1). The measured spectra are consistent with the TD-DFT simulated spectra, showing the EDA complex's absorbance maxima at 368 nm and absorbance tailing well into the visible region (Supplementary Section 6.3). The 1:1 ratio of components within the EDA complex was confirmed via a Job plot, wherein the ratio of donor and acceptor is plotted against the maximum absorbance (Fig. , Supplementary Section 5.5). Another important mechanistic route considered was the role of the phthalimide anion, formed upon fragmentation of the RAE, as an electron-rich donor that could activate a new EDA complex. Additionally, the 5 mol% Cs2CO3 added to accelerate the reaction, could similarly act as a donor in a new EDA and not just as a general base. Notably, the addition of 5 mol% Cs2CO3 does not increase the absorption of the chromophore at 450 nm (Fig. ).