To test these hypotheses, two experiments were conducted: one monitored using ¹H NMR and the other using cyclic voltammetry. Both experiments involved a diazonium salt without a redox-active group (dC12, synthesis route in SI-3), with a reduction potential similar to dC12TEMPO (see SI-6 for details), mixed with bare TEMPO or another reductant. These experiments are critical for validating or refuting the proposed mechanisms by which TEMPO radicals interfere with the grafting process.