Extended Data Fig. 5: Explored AuNP catalysed N-DMBI-H doping mechanisms.
From: Transition metal-catalysed molecular n-doping of organic semiconductors
All the investigated routes share the same first step, namely the hydride transfer from N-DMBI-H to AuNP surface. Depending on the possible active-doping-species, we propose four different reaction routes after the initial hydride transfer step. In route a, Aux–H– directly acts as the active-doping-species and forms Aux–H• after electron transfer to PDI, then, the H• on AuNP surface combines and releases H2 gas to regenerate clean AuNP surface for the next catalytic cycle. In route b, H• is released from Aux–H– to form Aux•− as the active-doping-species, then H• combines to give H2 gas, while Aux•− transfers the electron to the PDI and goes to the next catalytic cycle. In route c, H− is transferred from Aux–H– to PDI and forms hydrogenated PDI anion (denoted as PDI–H–) as the active-doping-species, which transfers electron to another PDI molecule and forms PDI–H•, then two PDI–H• combine each other to give H2 gas while PDI is regenerated for the next doping reaction cycle. Finally, in route d, H− is released from Aux–H– and serves as the active-doping-species, the clean AuNP surface goes to next catalytic cycle, while H− transfers the electron to the PDI and forms H• which combines to give H2 gas. For all the reaction routes, the final reaction products are N-DMBI+, PDI•− and H2 gas, AuNP only serves as the reaction catalyst. PDI-C6C7 molecule is modelled by a simpler PDI in which the 1-hexylheptyl side chain is replaced by a methyl group.
