TY - JOUR
T1 - Dynamic Electron Polarization Lasting More Than 10 μs by Hybridizing Porphyrin and TEMPO with Flexible Linkers
AU - Nishimura, Koki
AU - Yabuki, Reiya
AU - Hamachi, Tomoyuki
AU - Kimizuka, Nobuo
AU - Tateishi, Kenichiro
AU - Uesaka, Tomohiro
AU - Yanai, Nobuhiro
N1 - Funding Information:
This work was partly supported by the JST-FOREST Program (JPMJFR201Y) and JSPS KAKENHI (JP20H02713, JP 22K19051, and JP21J13049).
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/2/9
Y1 - 2023/2/9
N2 - Dynamic electron polarization (DEP), induced by quenching of photoexcited species by stable radicals, can hyperpolarize electron spins in solution at room temperature. Recently, development of technologies based on electron spin polarization such as dynamic nuclear polarization (DNP) has been progressing, where it is important to design molecules that achieve long-lasting DEP in addition to high DEP. Hybridization by linking dyes and radicals is a promising approach for efficient DEP, but strong interactions between neighboring dyes and radicals often result in the rapid decay of DEP. In this study, we introduce a flexible linker into the hybrid system of porphyrin and TEMPO to achieve both efficient DEP and long-lasting DEP. The structural flexibility of the linker switches the interaction between the radical and the triplet, which promotes the DEP process by bringing the radical and the triplet into close proximity, while avoiding abrupt relaxation due to strong interactions. As a result, the new hybridized system exhibits a larger DEP than the unlinked system, while at the same time achieving a DEP lasting more than 10 μs.
AB - Dynamic electron polarization (DEP), induced by quenching of photoexcited species by stable radicals, can hyperpolarize electron spins in solution at room temperature. Recently, development of technologies based on electron spin polarization such as dynamic nuclear polarization (DNP) has been progressing, where it is important to design molecules that achieve long-lasting DEP in addition to high DEP. Hybridization by linking dyes and radicals is a promising approach for efficient DEP, but strong interactions between neighboring dyes and radicals often result in the rapid decay of DEP. In this study, we introduce a flexible linker into the hybrid system of porphyrin and TEMPO to achieve both efficient DEP and long-lasting DEP. The structural flexibility of the linker switches the interaction between the radical and the triplet, which promotes the DEP process by bringing the radical and the triplet into close proximity, while avoiding abrupt relaxation due to strong interactions. As a result, the new hybridized system exhibits a larger DEP than the unlinked system, while at the same time achieving a DEP lasting more than 10 μs.
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U2 - 10.1021/acs.jpcb.2c07936
DO - 10.1021/acs.jpcb.2c07936
M3 - Article
C2 - 36717096
AN - SCOPUS:85147261145
SN - 1520-6106
VL - 127
SP - 1219
EP - 1228
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 5
ER -