祝贺赵子建同学的文章“Visible Light Generation of a Microsecond Long-Lived Potent Reducing Agent”在线发表于
Journal of the American Chemical Society（JACS），并被选为正面封面文章（Front Cover Paper），审稿人之一将其
高度评价为“A very significant advance on a conceptual and on a methodological (synthetic) level”。
工作简介：
光敏剂分子的双重激发态结合了两个光子能量，可突破单个光子的能量限制，已被广泛研究证明其具有极强的氧化还原能力。这使得如脱卤反应、伯奇还原以及芳烃氧化等许多高需能反应在温和条件下（室温、可见光激发）成为可能。苝酰二亚胺型（PDI）光敏剂是最早发现也是研究最为广泛的具有连续可见光激发电子转移性质的一类光敏剂。然而前期的超快吸收光谱动力学研究表明，尽管2(PDI•–)*具有较强的还原能力，但其寿命只有约~160 ps。极短的光敏剂激发态寿命使其难以突破扩散限制将高能电子转移至底物，这极大地限制了利用连续光激发产生的超强还原剂的应用范围，一般只能应用于高底物浓度（mM~M）的有机合成中。
复旦大学化学系胡可（点击查看介绍）课题组与北卡罗来纳大学教堂山分校Gerald Meyer教授（点击查看介绍）合作，将PDI光敏剂通过水杨酸基团锚定在介孔纳米晶二氧化锆（ZrO2）（常被看作绝缘体）表面，可见光激发下，2(PDI•–)*的高能电子注入ZrO2导带中，形成的电荷分离态ZrO2(e–)|PDI使高能电子的寿命延长至~53 μs。相比PDI•–的激发态寿命，提升了近6个数量级。
文章简介：
Photoexcitation of molecular radicals can produce strong reducing agents; however, the limited lifetimes of the doublet excited states preclude many applications. Herein, we propose and demonstrate a general strategy to translate a highly energetic electron from a doublet excited state to a ZrO2 insulator, thereby increasing the lifetime by about 6 orders of magnitude while maintaining a reducing potential less than −2.4 V vs SCE. Specifically, red light excitation of a salicylic acid modified perylene diimide radical anion PDI•− anchored to a ZrO2 insulator yields a ZrO2(e−)|PDI charge separated state with an ∼10 μs lifetime in 23% yield. The ZrO2(e−)s were shown to drive CO2 → CO reduction with a Re catalyst present in micromolar concentrations. More broadly, this strategy provides new opportunities to reduce important reagents and catalysts at low concentrations through diffusional electron transfer. Zhao, Z. et. al. J. Am. Chem. Soc. 2022
封面描述：
Visible light excitation of a perylenediimide radical anion results in electron injection into a ZrO2 insulator, yielding a potent reducing agent with a remarkable ~microsecond lifetime. The long-lived potent reducing agent provides new opportunities to reduce important reagents and catalysts present in low concentrations.
原文链接：