## 3 Results and Discussion  
The formation of HO\({}^{\bullet}\) was evaluated using the DMPO spin-trap, both in the absence of alkali and under strong alkaline conditions. The main results are gathered in Table 1a,b. The entry numbers will be used in the paper to refer to each experiment, e.g., DMPO + CuSO\({}_{4}\) is \"exp 1\".  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Entry** & **HCOO–** & **DMSO** & **H\({}_{2}\)O\({}_{2}\)** & **Additive** & **Details** & \begin{tabular}{c} **Total Peak** \\ **Area (a.u.)** \\ \end{tabular} & \begin{tabular}{c} **DMPO–OH** \\ **(v2)** \\ \end{tabular} & \begin{tabular}{c} **DMPO–CH** \\ **(v3)** \\ \end{tabular} & \begin{tabular}{c} **DMPO–COO** \\ **(v4)** \\ \end{tabular} & \
\begin{tabular}{c} **DMPO–R** \\ **(v5)** \\ \end{tabular} &
\begin{tabular}{c} **Imple (\%)** \\ \end{tabular} \\ \hline  & & & & & & & & & & \\ \hline  & & & & & & & & & & & \\ \hline
1 & & & & & CuSO\({}_{4}\) & 1.12 & 5 & & & & 74 & 8 \\
2 & & & & Cu-Phen & 1.46 & 6 & & & 77 & 17 \\
3 & & & x & Cu-Phen & 1.29 & 38 & & & 54 & 8 \\
4 & & & x & Cu-Phen & 1.2 & 18 & 73 & & 4.5 & 4.5 \\
5 & x & & x & Cu-Phen & 0.65 & 18 & & 49 & 28 & 5 \\
6 & x & & x & Cu-Phen & +10\({}^{7}\) b & 0.54 & 14 & & 70 & 12 & 4 \\
7 & x & & x & Cu-Phen & H\({}^{\,4}\) & 0.79 & 10 & & 79 & 8 & 3 \\
8 & & & x & CuSO\({}_{4}\) & 0.89 & 7 & & & 57 & 16 \\
9 & & x & x & CuSO\({}_{4}\) & 0.83 & 16 & & & 76 & 8 \\
10 & x & & x & CuSO\({}_{4}\) & 0.21 & 15 & & 23 & 34 & 10 \\
11 & & & x & FeSO\({}_{4}\) & pH 3 & 0.43 & 86 & & & 7 & 7 \\
12 & & x & & CuSO\({}_{4}\) & 0.82 & 14 & & & 78 & 8 \\
13 & & & x & Cu-Phen & 1.0 & 22 & & & 72 & 6 \\
14 & x & & & Cu-Phen & 0.79 & 19 & & 11 & 58 & 12 \\
15 & x & & & Cu-Phen & H & 0.84 & 11 & & 72 & 13 & 4 \\
16 & & & x & / & H & 0.35 & 38 & & 38 & 24 \\ \hline  & & & & & **(b)** & & & & & \\ \hline
17 & & & & CuSO\({}_{4}\) & & 0.62 & 2 & & & 72 & 6 \\
18 & & & Cu-Phen & 0.55 & 17 & & & 58 & 10 \\
19 & x & & & Cu-Phen & +8\({}^{\prime}\) c & 0.54 & & & 92 & 8 \\
20 & & & x & Cu-Phen & 0.72 & 21 & & & 69 & 11 \\
21 & & x & & Cu-Phen & 0.12 & 16 & 80 & & 5 \\
22 & x & & x & Cu-Phen & 0.72 & 17 & & 47 & 28 & 8 \\ \hline \hline \end{tabular} For all methods conducted in the absence of DMPO, no EPR signal was observed (not shown). In some cases (entries 1,8, and 10), secondary adducts were found by simulation. Their relative areas (%) are presented in the Supplementary Materials. \({}^{\,4}\)Heeting. \({}^{\,5}\)+10 min. For all controls conducted in the absence of DMPO, no EPR signal was observed (not shown). In some cases (entries 17 and 18), secondary adducts were found by simulation. Their relative areas (%) are presented in the Supplementary Materials. \({}^{\,5}\)+8 min.  
\end{table}
Table 1: **(a)** Integration and simulation results at near-neutral pH: total peak area, and distribution of DMPO adducts and degradation products for some experiments, as relative areas of each radical, in percent. **(b)** Integration and simulation results at alkaline pH (with NaOH); total peak area, and distribution of DMPO adducts and degradation products for some experiments, as relative areas of each radical, in percent.