Engineering High-Potential Photo-oxidants with Panchromatic Absorption
Engineering High-Potential Photo-oxidants with Panchromatic Absorption
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DOI：
10.1021/jacs.7b04400
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发表时间：
2017-06-28
影响因子：
15
通讯作者：
Therien, Michael J.
中科院分区：
文献类型：
--
作者：
Jiang, Ting;Polizzi, Nicholas F.;Therien, Michael J.
光化学反应需要高潜力的吸收可见光的光氧化剂。我们报道了（i）一个高度缺电子的Ru（II）配合物（eDef-Rutpy）具有比任何已建立的Ru（II）bis的E-1/2（0/+）电位更正的超过300 mV的电位（三吡啶基）衍生物，和（ii）乙炔桥连的eDef-Rutpy-（卟啉合）Zn（II）（eDef-RuPZn）超分子，其提供全色UV-可见光谱域吸收率和高E-1/2（0/+）电势，与Ce（NH 4）（2）（NO3）（6）[E-1/2（Ce 3 +/（4+））= 1.61 V vs NHE]相当，后者是一种常用于有机官能团转化的强且通用的基态氧化剂。eDef-RuPZn在380-700 nm范围内表现出比常规Ru（II）多吡啶配合物高8倍的吸收振荡器强度，以及令人印象深刻的激发态还原电位（E-1（-/*）= 1.59 V; 3E（-/*）= 1.26 V）。eDef-RuPZn表现出电子激发的单重态和三重态电荷转移态寿命比传统的Ru（II）双（三联吡啶）发色团的典型寿命长2个数量级以上，这表明在光驱动的氧化反应中的能量转换和还原的新机会。
Challenging photochemistry demands high-potential visible-light-absorbing photo-oxidants. We report (i) a highly electron-deficient Ru(II) complex (eDef-Rutpy) bearing an E-1/2(0/+) potential more than 300 mV more positive than that of any established Ru(II) bis(terpyridyl) derivative, and (ii) an ethyne-bridged eDef-Rutpy-(porphinato)Zn(II) (eDef-RuPZn) supermolecule that affords both panchromatic UV-vis spectral domain absorptivity and a high E-1/2(0/+) potential, comparable to that of Ce(NH4)(2)(NO3)(6) [E-1/2(Ce3+/(4+)) = 1.61 V vs NHE], a strong and versatile ground-state oxidant commonly used in organic functional group transformations. eDef-RuPZn exhibits similar to 8-fold greater absorptive oscillator strength over the 380-700 nm range relative to conventional Ru(II) polypyridyl complexes, and impressive excited-state reduction potentials (E-1(-/*) = 1.59 V; 3E(-/*) = 1.26 V). eDef-RuPZn manifests electronically excited singlet and triplet charge-transfer state lifetimes more than 2 orders of magnitude longer than those typical of conventional Ru(II) bis(terpyridyl) chromophores, suggesting new opportunities in light-driven oxidation reactions for energy conversion and photocatalysis.