biostudies-literatureOdella EU.S. Department of Energy12667-12675https://www.ebi.ac.uk/biostudies/studies/S-EPMC8494046biostudies-literatureUnknown12(38)Proton-coupled electron transfer (PCET) reactions depend on the hydrogen-bond connectivity between sites of proton donors and acceptors. The 2-(2'-hydroxyphenyl) benzimidazole (BIP) based systems, which mimic the natural Tyr_Z-His190 pair of Photosystem II, have been useful for understanding the associated PCET process triggered by one-electron oxidation of the phenol. Substitution of the benzimidazole by an appropriate terminal proton acceptor (TPA) group allows for two-proton translocations. However, the prototropic properties of substituted benzimidazole rings and rotation around the bond linking the phenol and the benzimidazole can lead to isomers that interrupt the intramolecular hydrogen-bonded network and thereby prevent a second proton translocation. Herein, a strategic sChemical scienceMulti PCET in symmetrically substituted benzimidazoles.PMC8494046DE-FG02-03ER15393Moore TASecor MHammes-Schiffer SGroy TLMoore ALElliott MOdella EfalseMulti PCET in symmetrically substituted benzimidazoles.Proton-coupled electron transfer (PCET) reactions depend on the hydrogen-bond connectivity between sites of proton donors and acceptors. The 2-(2'-hydroxyphenyl) benzimidazole (BIP) based systems, which mimic the natural Tyr_Z-His190 pair of Photosystem II, have been useful for understanding the associated PCET process triggered by one-electron oxidation of the phenol. Substitution of the benzimidazole by an appropriate terminal proton acceptor (TPA) group allows for two-proton translocations. However, the prototropic properties of substituted benzimidazole rings and rotation around the bond linking the phenol and the benzimidazole can lead to isomers that interrupt the intramolecular hydrogen-bonded network and thereby prevent a second proton translocation. Herein, a strategic s2021-01-01T00:00:00Z2021 Oct2025-04-19T21:38:02.225Z2025-04-19T21:38:02.225ZS-EPMC84940463470355210.1039/d1sc03782j