The direct oxidations of meso-tetrakis(pentafluorophenyl)porphyrin usingcetyltrimethylammoniumpermanganate (CTAP), RuCl3/Oxone/base or Ag+/oxalic acid each generate distinctive product mixtures that may contain, inter alia, porpho-mono-, di-, and trilactones. The CTAP and RuCl3/Oxone/base oxidations also generate a unique open chain tripyrrin derived from the degradation of a porpholactone oxazolone
使用十六烷基三甲基高锰酸铵 (CTAP)、RuCl 3 /Oxone/碱或 Ag + /草酸直接氧化内消旋四(五氟苯基)卟啉,每种都会产生独特的产物混合物,其中可能含有单卟啉、二卟啉、和三内酯。 CTAP和RuCl 3 /Oxone/碱氧化还产生源自卟啉内酯恶唑酮部分降解的独特开链三吡啉。因此,其形成和结构与所有生物或几乎所有其他非生物胆绿素样线性卟啉类降解产物明显不同,这些降解产物源自吡咯结构单元之间的环裂解。
Switching Electrocatalytic Hydrogen Evolution Pathways through Electronic Tuning of Copper Porphyrins
The electronic structure of metal complexes plays key roles in determining their catalytic features. However, controlling electronic structures to regulate reaction mechanisms is of fundamental interest but has been rarely presented. Herein, we report electronic tuning of Cu porphyrins to switch pathways of the hydrogen evolution reaction (HER). Through controllable and regioselective β‐oxidation of Cu porphyrin 1, we synthesized analogues 2–4 with one or two β‐lactone groups in either a cis or trans configuration. Complexes 1–4 have the same Cu‐N4 core site but different electronic structures. Although β‐oxidation led to large anodic shifts of reductions, 1–4 displayed similar HER activities in terms of close overpotentials. With electrochemical, chemical and theoretical results, we show that the catalytically active species switches from a CuI species for 1 to a Cu0 species for 4. This work is thus significant to present mechanism‐controllable HER via electronic tuning of catalysts.