A perylene (Pery)–phenoxazine (PXZ) compact orthogonal electron donor/acceptor dyad was prepared to study the relationship between the molecular structures and the spin–orbit charge transfer intersystem crossing (SOCT-ISC), as well as the electron spin selectivity of the ISC process. The geometry of Pery–PXZ (80.0°) is different from the previously reported perylene–phenothiazine dyad (Pery–PTZ, 91.5°), although there is only one atom variation for the two dyads. Pery–PXZ shows a high singlet oxygen quantum yield (84%). Femtosecond transient absorption spectra indicate that the charge separation (CS, faster than 120 fs) is faster than the Pery–PTZ analog (CS, 250 fs) and charge recombination (CR, i.e., SOCT-ISC, 5.98 ns) of Pery–PXZ is slower than the Pery–PTZ analog (CR, 0.9 ns). The intrinsic triplet state lifetime of Pery–PXZ is 242 µs vs the lifetime of 181 µs for the Pery–PTZ analog. Moreover, the triplet state lifetime of Pery–PXZ in the solid polymer matrix is extended to 4.45 ms, which indicates that the triplet state of Pery–PXZ in fluid solution is deactivated not only by the triplet–triplet annihilation effect but also by other factors such as vibration coupled relaxation. Interestingly, with pulsed laser excited time-resolved electron paramagnetic resonance spectroscopy, the electron spin polarization (ESP) pattern of the triplet state of the current dyad is opposite to that of Pery–PTZ. These results demonstrated the rich electron spin chemistry of the ISC of compact electron donor/acceptor dyads, e.g., the ESP is dependent on not only the molecular geometry but also the structure of the electron donor (or acceptor).

中文翻译：

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一原子取代对光物理性质和电子自旋极化的影响：紧凑的正交per /吩恶嗪电子供体/受体二元体系间的交叉

制备了per（Pery）-吩恶嗪（PXZ）紧凑的正交电子给体/受体二聚体，以研究分子结构与自旋-轨道电荷转移系统间穿越（SOCT-ISC）之间的关系以及电子的自旋选择性ISC流程。Pery–PXZ（80.0°）的几何形状与先前报道的per-吩噻嗪二聚体（Pery–PTZ，91.5°）不同，尽管两个双原子只有一个原子变化。Pery–PXZ显示出高的单重态氧量子产率（84％）。飞秒瞬态吸收光谱表明，电荷分离（CS，快于120 fs）比Pery–PTZ模拟物（CS，快250 fs）和电荷重组（CR，即SOCT-ISC，5.98 ns）快。Pery–PXZ比Pery–PTZ模拟（CR，0.9 ns）要慢。的固有三重态寿命佩里-PXZ是242 μ s和181的寿命μ S为佩里-PTZ类似物。此外，固体聚合物基质中Pery–PXZ的三重态寿命延长至4.45 ms，这表明Pery–PXZ的三重态处于有效状态。不仅由于三重态-三重态an灭效应而失活，而且诸如振动耦合弛豫等其他因素也使该溶液失活。有趣的是，利用脉冲激光激发的时间分辨电子顺磁共振波谱，电流二元组三重态的电子自旋极化（ESP）模式与Pery–PTZ相反。这些结果证明了紧密电子供体/受体二元组的ISC的富电子自旋化学，例如ESP不仅取决于分子几何形状，还取决于电子供体（或受体）的结构。