Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Electronic coupling and spin-orbit charge transfer intersystem crossing (SOCT-ISC) in compact BDP-carbazole dyads with different mutual orientations of the electron donor and acceptor. / Hou, Yuqi; Kurganskii, Ivan; Elmali, Ayhan и др.
в: Journal of Chemical Physics, Том 152, № 11, 114701, 21.03.2020.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Electronic coupling and spin-orbit charge transfer intersystem crossing (SOCT-ISC) in compact BDP-carbazole dyads with different mutual orientations of the electron donor and acceptor
AU - Hou, Yuqi
AU - Kurganskii, Ivan
AU - Elmali, Ayhan
AU - Zhang, Huimin
AU - Gao, Yuting
AU - Lv, Lingling
AU - Zhao, Jianzhang
AU - Karatay, Ahmet
AU - Luo, Liang
AU - Fedin, Matvey
PY - 2020/3/21
Y1 - 2020/3/21
N2 - In order to study the spin-orbit charge transfer induced intersystem crossing (SOCT-ISC), Bodipy (BDP)-carbazole (Cz) compact electron donor/acceptor dyads were prepared. Charge transfer (CT) emission bands were observed for dyads showing strong electronic coupling between the donor and the acceptor (coupling matrix elements VDA, 0.06 eV-0.18 eV). Depending on the coupling magnitude, the CT state of the dyads can be either dark or emissive. Equilibrium between the 1LE (locally excited) state and the 1CT state was confirmed by temperature-dependent fluorescence studies. Efficient ISC was observed for the dyads with Cz connected at the meso-position of the BDP. Interestingly, the dyad with non-orthogonal geometry shows the highest ISC efficiency (φΔ = 58%), which is different from the previous conclusion. The photo-induced charge separation (CS, time constant: 0.7 ps) and charge recombination (CR, ∼3.9 ns) were studied by femtosecond transient absorption spectroscopy. Nanosecond transient absorption spectroscopy indicated that the BDP-localized triplet state was exceptionally long-lived (602 μs). Using pulsed laser excited time-resolved electron paramagnetic resonance spectroscopy, the SOCT-ISC mechanism was confirmed, and we show that the electron spin polarization of the triplet state is highly dependent on the mutual orientation of the donor and acceptor. The dyads were used as triplet photosensitizers for triplet-triplet-annihilation (TTA) upconversion, and the quantum yield is up to 6.7%. TTA-based delayed fluorescence was observed for the dyads (τDF = 41.5 μs). The dyads were also used as potent photodynamic therapy reagents (light toxicity of IC50 = 0.1 μM and dark toxicity of IC50 = 70.8 μM).
AB - In order to study the spin-orbit charge transfer induced intersystem crossing (SOCT-ISC), Bodipy (BDP)-carbazole (Cz) compact electron donor/acceptor dyads were prepared. Charge transfer (CT) emission bands were observed for dyads showing strong electronic coupling between the donor and the acceptor (coupling matrix elements VDA, 0.06 eV-0.18 eV). Depending on the coupling magnitude, the CT state of the dyads can be either dark or emissive. Equilibrium between the 1LE (locally excited) state and the 1CT state was confirmed by temperature-dependent fluorescence studies. Efficient ISC was observed for the dyads with Cz connected at the meso-position of the BDP. Interestingly, the dyad with non-orthogonal geometry shows the highest ISC efficiency (φΔ = 58%), which is different from the previous conclusion. The photo-induced charge separation (CS, time constant: 0.7 ps) and charge recombination (CR, ∼3.9 ns) were studied by femtosecond transient absorption spectroscopy. Nanosecond transient absorption spectroscopy indicated that the BDP-localized triplet state was exceptionally long-lived (602 μs). Using pulsed laser excited time-resolved electron paramagnetic resonance spectroscopy, the SOCT-ISC mechanism was confirmed, and we show that the electron spin polarization of the triplet state is highly dependent on the mutual orientation of the donor and acceptor. The dyads were used as triplet photosensitizers for triplet-triplet-annihilation (TTA) upconversion, and the quantum yield is up to 6.7%. TTA-based delayed fluorescence was observed for the dyads (τDF = 41.5 μs). The dyads were also used as potent photodynamic therapy reagents (light toxicity of IC50 = 0.1 μM and dark toxicity of IC50 = 70.8 μM).
KW - TRIPLET-TRIPLET ANNIHILATION
KW - SINGLET OXYGEN GENERATION
KW - PHOTON UP-CONVERSION
KW - BODIPY-ANTHRACENE DYADS
KW - TIME-RESOLVED EPR
KW - STATE FORMATION
KW - PHOTODYNAMIC THERAPY
KW - EXCITED-STATES
KW - LOW-POWER
KW - HIGHLY EFFICIENT
UR - http://www.scopus.com/inward/record.url?scp=85082092428&partnerID=8YFLogxK
U2 - 10.1063/1.5145052
DO - 10.1063/1.5145052
M3 - Article
C2 - 32199436
AN - SCOPUS:85082092428
VL - 152
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 11
M1 - 114701
ER -
ID: 23892892