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Excited-state antiaromaticity relief drives facile photoprotonation of carbons in aminobiphenyls.

ABSTRACT: A combined computational and experimental study reveals that ortho-, meta- and para-aminobiphenyl isomers undergo distinctly different photochemical reactions involving proton transfer. Deuterium exchange experiments show that the ortho-isomer undergoes a facile photoprotonation at a carbon atom via excited-state intramolecular proton transfer (ESIPT). The meta-isomer undergoes water-assisted excited-state proton transfer (ESPT) and a photoredox reaction via proton-coupled electron transfer (PCET). The para-isomer undergoes a water-assisted ESPT reaction. All three reactions take place in the singlet excited-state, except for the photoredox process of the meta-isomer, which involves a triplet excited-state. Computations illustrate the important role of excited-state antiaromaticity relief in these photoreactions.

SUBMITTER: Drazenovic J

PROVIDER: S-EPMC10988595 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature

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Excited-state antiaromaticity relief drives facile photoprotonation of carbons in aminobiphenyls.

Draženović Josip J Laconsay Croix J CJ Došlić Nađa N I-Chia Wu Judy J Basarić Nikola N

Chemical science 20240304 14

A combined computational and experimental study reveals that ortho-, meta- and para-aminobiphenyl isomers undergo distinctly different photochemical reactions involving proton transfer. Deuterium exchange experiments show that the ortho-isomer undergoes a facile photoprotonation at a carbon atom via excited-state intramolecular proton transfer (ESIPT). The meta-isomer undergoes water-assisted excited-state proton transfer (ESPT) and a photoredox reaction ...[more]

PMID: 38577382

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