TEMPO-derivatized anilines were successfully synthesized through customized synthetic routes. These strategies, which preserve the integrity of the TEMPO group throughout the process, hold potential for broader application to other redox functionalities. Interestingly, the diazotization step significantly the redox state of TEMPO, depending on the diazotization agents used. Cyclic voltammetry studies, supported by simulations mimicking diazotization conditions, confirmed these redox changes. The difference in redox balance between the two dC12TEMPO batches (dC12TEMPONOBF4 or dC12TEMPOtBuONO/BF3) directly impacted their immobilization efficiency during the formation of TEMPObased layers. Diazonium salts dC12TEMPONOBF4, where TEMPO only existed in its radical form during electroreduction, exhibited lower immobilization efficiency. In contrast, diazonium salts dC 12 TEMPO tBuONO/BF3 , containing non-radical species, achieved higher immobilization efficiency, as evidenced by greater surface concentrations. Further investigations suggest that the spontaneous parasitic reduction of diazoniums by TEMPO radicals likely reduced the amount of immobilized species, explaining the observed inefficiency.