Ségaud Nathalie, De Thomasson Constance, Daverat Caroline, Sénéchal-David Katell, Dos Santos Amandine, Steinmetz Vincent, Maître Philippe, Rebilly Jean-Noël, Banse Frédéric, Reinaud Olivia
Institut de Chimie Moléculaire et des Matériaux d'Orsay, Laboratoire de Chimie Inorganique, Université Paris Sud, Université Paris Saclay, CNRS, 91405, Orsay, France.
CNRS UMR 8601, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, Sorbonne Paris Cité, 75006, Paris, France.
Chemistry. 2017 Feb 24;23(12):2894-2906. doi: 10.1002/chem.201605248. Epub 2017 Jan 27.
A heteroditopic ligand associated with a calix[6]arene scaffold bearing a tris(imidazole) coordinating site at its small rim and an amine/pyridine ligand at its large rim has been prepared, and its regioselective coordination to Zn at the small rim and Fe in the amine/pyridine ligand has been achieved. The heterodinuclear complex obtained displays an overall cone conformation capped by the tris(imidazole)Zn moiety and bears a non-heme Fe complex at its base. Each of the metal centers exhibits one labile position, allowing the coordination inside the cavity of a guest alkylamine at Zn and the generation of reaction intermediates (Fe (OOH) and Fe O) at the large rim. A dependence between the chain length of the encapsulated alkylamine and the distribution of Fe (OOH) intermediates and Fe (OMe) is observed. In addition, it is shown that the generation of the Fe O intermediate is enhanced by addition of the alkylamine guest. Hence, this supramolecular system gathers the three levels of reactivity control encountered in oxidoreductases: i) control of the Fe redox properties through its first coordination sphere, allowing us to generate high valent reactive species; ii) control of guest binding through a hydrophobic funnel that drives its alkyl chain next to the reactive iron complex, thus mimicking the binding pocket of natural systems; iii) guest-modulated reactivity of the Fe center towards oxidants.
已制备出一种与杯[6]芳烃骨架相连的异二齿配体，该配体在其小边缘带有三（咪唑）配位位点，在其大边缘带有胺/吡啶配体，并实现了其在小边缘与锌的区域选择性配位以及在胺/吡啶配体中与铁的配位。所得到的异双核配合物呈现出由三（咪唑）锌部分封端的整体锥构象，并且在其底部带有一个非血红素铁配合物。每个金属中心都有一个不稳定位置，使得客体烷基胺能够在锌处的腔内配位，并在大边缘生成反应中间体（Fe（OOH）和Fe O）。观察到被封装的烷基胺的链长与Fe（OOH）中间体和Fe（OMe）的分布之间存在依赖性。此外，结果表明添加客体烷基胺可增强Fe O中间体的生成。因此，这个超分子体系汇集了氧化还原酶中遇到的三个反应性控制水平：i）通过其第一配位层控制铁的氧化还原性质，使我们能够生成高价活性物种；ii）通过疏水通道控制客体结合，该通道将其烷基链驱动至反应性铁配合物附近，从而模拟天然体系的结合口袋；iii）客体调节铁中心对氧化剂的反应性。
