Barrierless Heptazine-Driven Excited State Proton-Coupled Electron Transfer: Implications for Controlling Photochemistry of Carbon Nitrides and Aza-Arenes
Barrierless Heptazine-Driven Excited State Proton-Coupled Electron Transfer: Implications for Controlling Photochemistry of Carbon Nitrides and Aza-Arenes
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DOI：
10.1021/acs.jpcc.9b08842
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发表时间：
2019-11
影响因子：
3.7
通讯作者：
Emily J Rabe;Kathryn L Corp;Xiang Huang;Johannes Ehrmaier;Ryan G. Flores;Sabrina L Estes;A. Sobolewski;W. Domcke;Cody W. Schlenker
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文献类型：
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作者：
Emily J Rabe;Kathryn L Corp;Xiang Huang;Johannes Ehrmaier;Ryan G. Flores;Sabrina L Estes;A. Sobolewski;W. Domcke;Cody W. Schlenker
为了告知用于控制氮杂芳烃光化学的前瞻性设计规则，我们研究了2，5，8-三（4-甲氧基苯基）-1，3，4，6，7，9，9 b-七氮杂非那烯（TAHz）与各种苯酚衍生物的氢键复合物，TAHz是一种与石墨碳氮化物化学相关的分子光催化剂。我们一直专注于激发态质子耦合电子转移（ES-PCET）反应的heptazines，因为激发态的属性管理这个过程中仍然概念上不透明的质子还原反应相比，这些材料。我们使用基态吸收，时间分辨光致发光，从头计算量子化学计算来分析TAHz对一系列的六个对位取代苯酚衍生物的反应性。我们确定了缔合常数（KA），激发态猝灭速率常数（kQ），动力学同位素效应（KIE）和过渡态势垒（ΔE）。从这些数据中，我们提供了一个概括的图片氢键形成和激发态反应的庚嗪为基础的…
To inform prospective design rules for controlling aza-arene photochemistry, we studied hydrogen-bonded complexes of 2,5,8-tris(4-methoxyphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (TAHz), a molecular photocatalyst chemically related to graphitic carbon nitride, with a variety of phenol derivatives. We have focused on excited-state proton-coupled electron transfer (ES-PCET) reactions of heptazines since the excited-state properties governing this process remain conceptually opaque compared to proton reduction reactions for these materials. We used ground-state absorption, time-resolved photoluminescence, and ab initio quantum chemical calculations to analyze TAHz reactivity towards a series of six para-substituted phenol derivatives. We determined association constants (KA), excited-state quenching rate constants (kQ), kinetic isotope effects (KIE), and transition-state barriers (ΔE‡). From this data we provide a generalizable picture of hydrogen bond formation and excited-state reactivity of heptazine-based...