TY - JOUR

T1 - Photophysical properties of perylenebisimide derivatives studied by time-resolved transient optical and electron paramagnetic resonance spectroscopy

AU - Li, Wenhui

AU - Li, Jiayu

AU - Kurganskii, Ivan

AU - Ye, Kaiyue

AU - Zhang, Xue

AU - Zhao, Jianzhang

AU - Li, Ming De

AU - Dick, Bernhard

AU - Fedin, Matvey

N1 - J.Z. acknowledges the NSFC (Grant Nos. 22473021 and U2001222), the National Key Research and Development Program of China (Grant No. 2023YFE0197600), the State Key Laboratory of Fine Chemicals, the Research and Innovation Team Project of Dalian University of Technology (Grant No. DUT2022TB10), and the Fundamental Research Funds for the Central Universities (Grant No. DUT22LAB610) for financial support. X.Z. acknowledges the NSFC (Grant No. 22403013), the China Postdoctoral Science Foundation (Grant No. 2024M750321), and the Postdoctoral Fellowship Program of CPSF for financial support. I.K. acknowledges the Russian Science Foundation (Grant No. 25-23-00545), and M.F. acknowledges the Ministry of Science and Higher Education of the RF. Photophysical properties of perylenebisimide derivatives studied by time-resolved transient optical and electron paramagnetic resonance spectroscopy / Wenhui Li, Jiayu Li, Ivan Kurganskii, Kaiyue Ye, Xue Zhang, Jianzhang Zhao, Ming-De Li, Bernhard Dick, Matvey Fedin // Journal of Chemical Physics. - 2025. - № 163. Т. 16. - С. 164304

PY - 2025

Y1 - 2025

N2 - We studied the intersystem crossing (ISC) of the neutral, monoanionic, and dianionic forms of two perylenebisimide PBI derivatives with twisted π-conjugation framework in the molecular structure: one is substituted with four chloride atoms (PBI-Cl), whereas the other has a fused dimeric molecular structure (DiPBI). PBI-Cl is highly fluorescent, and no ISC was observed. However, the DiPBI shows efficient ISC (triplet state lifetime τT = 3.6 μs), supported by theoretical computation with the Herzberg-Teller effect taken into account. Time-resolved electron paramagnetic resonance spectra of the triplet state of DiPBI show that the zero field splitting (ZFS) D parameter is 778 MHz, indicating that the electron spin density is delocalized, because the ZFS D is much smaller than the triplet state of the unsubstituted PBI (D = 1303 MHz). No ISC was observed for the dianion [DiPBI]2−, whereas for [PBI-Cl]2, ISC was observed. This result infers that twisting of the π-conjugation framework of a molecular structure does not necessarily induce ISC, and excited state energy level matching of S1/Tn states may play the decisive role in ISC. These studies are helpful to fully exploit the super strong reductivity of photoexcited dianions in photocatalytic redox organic reactions due to the enhanced intermolecular electron transfer based on the long-lived triplet excited state of the dianions.

AB - We studied the intersystem crossing (ISC) of the neutral, monoanionic, and dianionic forms of two perylenebisimide PBI derivatives with twisted π-conjugation framework in the molecular structure: one is substituted with four chloride atoms (PBI-Cl), whereas the other has a fused dimeric molecular structure (DiPBI). PBI-Cl is highly fluorescent, and no ISC was observed. However, the DiPBI shows efficient ISC (triplet state lifetime τT = 3.6 μs), supported by theoretical computation with the Herzberg-Teller effect taken into account. Time-resolved electron paramagnetic resonance spectra of the triplet state of DiPBI show that the zero field splitting (ZFS) D parameter is 778 MHz, indicating that the electron spin density is delocalized, because the ZFS D is much smaller than the triplet state of the unsubstituted PBI (D = 1303 MHz). No ISC was observed for the dianion [DiPBI]2−, whereas for [PBI-Cl]2, ISC was observed. This result infers that twisting of the π-conjugation framework of a molecular structure does not necessarily induce ISC, and excited state energy level matching of S1/Tn states may play the decisive role in ISC. These studies are helpful to fully exploit the super strong reductivity of photoexcited dianions in photocatalytic redox organic reactions due to the enhanced intermolecular electron transfer based on the long-lived triplet excited state of the dianions.

UR - https://www.mendeley.com/catalogue/5214a1a1-7ad4-3ed5-8a53-48e90516eb69/

UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105019176490&origin=inward

U2 - 10.1063/5.0277710

DO - 10.1063/5.0277710

M3 - Article

VL - 163

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 16

M1 - 164304

ER -