LaDuca Andrew R, Gonder Jared E, Sarkar Writhabrata, Gilbertson John D, Szymczak Nathaniel K
Department of Chemistry, University of Michigan Ann Arbor MI USA
Department of Chemistry, Western Washington University Bellingham WA USA
Chem Sci. 2025 Aug 29. doi: 10.1039/d5sc04153h.
A non-heme iron(ii) complex bearing a ligand with secondary sphere hydrogen bond (H-bond) donors, (tris(6-phenylaminopyridylmethyl)amine, TPA, rapidly reduces nitrite (NO ) to nitric oxide (NO) in the absence of exogenous additives, affording a Fe(iii)(μ-O) diamond core. An electronically analogous complex containing a ligand without H-bonds (tris(6-methylpyridylmethylamine), TPA, also reduces NO to NO and forms an Fe(iii)(μ-O) core, but is four orders of magnitude slower, highlighting the impact of H-bonds to promote NO reduction. We compare the structural and spectroscopic differences of the two Fe(iii)(μ-O) complexes and show that H-bonding interactions weaken the Fe-O bonds, perturb the electronic structure of the FeO cores, and thereby engender distinct reductive stability profiles.
一种带有具有二级球氢键（H键）供体的配体的非血红素铁（II）配合物（三（6-苯基氨基吡啶基甲基）胺，TPA），在没有外源添加剂的情况下能迅速将亚硝酸盐（NO₂⁻）还原为一氧化氮（NO），形成一个Fe（III）（μ-O）菱形核心。一种含有没有氢键的配体的电子类似配合物（三（6-甲基吡啶基甲基胺），TPA），也能将NO₂⁻还原为NO并形成一个Fe（III）（μ-O）核心，但速度要慢四个数量级，突出了氢键对促进NO₂⁻还原的影响。我们比较了两种Fe（III）（μ-O）配合物的结构和光谱差异，结果表明氢键相互作用削弱了Fe-O键，扰乱了FeO核心的电子结构，从而产生了不同的还原稳定性分布。
