Synthesis and optical properties of phenazinone-based photosensitizers for singlet oxygen generation
Synthesis and optical properties of phenazinone-based photosensitizers for singlet oxygen generation
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用于单线态氧生成的吩嗪酮光敏剂的合成和光学性质
DOI：
10.1039/d2nj05322e
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发表时间：
2023
影响因子：
3.3
通讯作者：
Yousuke Ooyama
中科院分区：
文献类型：
--
作者：
Kazuki Ohira;Masahiro Yamamoto;Keiichi Imato;Yousuke Ooyama
设计并开发了其中羰基结合到发色团中的吩嗪酮衍生物PZ 1 - 3作为具有产生单线态氧（1O 2）的能力的无卤素原子的杂蒽基光敏剂。与没有羰基的吩嗪-2，3-二醇（PZ）相比，PZ 1 - 3在480 nm附近的摩尔吸收系数增加了5至6倍。此外，PZ1 - 3的荧光量子产率（Φ fl）值显著低（PZ1为0.03，PZ2为0.04，PZ3为0.05）。为了评价PZ1 - 3的1O2生成能力，估算了PZ1 - 3的1O2量子产率（Φ Δ），结果表明，PZ1显示出比已知作为参比光敏剂的玫瑰红（RB）更高的Φ Δ值，以生成1O2（PZ1为0.86，PZ2为0.54，PZ3为0.069，RB为0.68）。此外，PZ 1 - 3的速率常数（kr、knr、kISC和kIC）表明，PZ 2和PZ 3的低Φ Δ的原因分别来自于柔性甲氧基甲氧基和4-氯苯甲酸酯基团引起的振动弛豫。密度泛函理论（DFT）、含时密度泛函理论（TD-DFT）和自然跃迁轨道（NTO）计算表明，PZ 1 - 3从最低激发单重态（S1）到第三重态（T3）的系间跃迁（ISC）过程在热力学上是可行的，并且基于El-Sayed规则。因此，我们认为吩嗪酮骨架是一种很有前途的无卤杂蒽类发色团光敏剂。
Phenazinone derivatives PZ1–3 where a carbonyl group is incorporated into the chromophore are designed and developed as halogen-atom-free-heteroanthracene-based photosensitizers possessing the ability to generate singlet oxygen (1O2). Compared to the phenazine-2,3-diol (PZ) without a carbonyl group, the molar absorption coefficients of PZ1–3 at around 480 nm increased by a factor of five to six. Furthermore, the values of fluorescence quantum yields (Φfl) of PZ1–3 were significantly low (0.03 for PZ1, 0.04 for PZ2, and 0.05 for PZ3). To evaluate the 1O2 generation ability of PZ1–3, the 1O2 quantum yields (ΦΔ) of PZ1–3 were estimated and it was demonstrated that PZ1 exhibited a higher ΦΔ value than rose bengal (RB) known as a reference photosensitizer to generate 1O2 (0.86 for PZ1, 0.54 for PZ2, 0.069 for PZ3, and 0.68 for RB). Moreover, the rate constants (kr, knr, kISC, and kIC) of PZ1–3 indicated that the reason for the low ΦΔ of PZ2 and PZ3 comes from the vibrational relaxation caused by a flexible methoxymethoxy and 4-chlorobenzoate group, respectively. Density functional theory (DFT), time-dependent DFT (TD-DFT), and natural transition orbital (NTO) calculations suggested that for PZ1–3, the intersystem crossing (ISC) processes from the lowest excited singlet state (S1) to the third triplet state (T3) are thermodynamically feasible and facilitated based on El-Sayed's rule. Consequently, we propose that the phenazinone skeleton is one of the promising halogen-atom-free-heteroanthracene-based chromophore photosensitizers.