As metalloproteins exemplify, the chemical and physical properties of metal centers depend not only on their first but also on their second coordination sphere. Installing arrays of functional groups around the first coordination sphere of synthetic metal complexes is thus highly desirable, but it remains a challenging objective. Here we introduce a novel approach to produce tailored second coordination spheres. We used bioinspired artificial architectures based on aromatic oligoamide foldamers to construct a rigid, modular and well-defined environment around a metal complex. Specifically, aza-aromatic monomers having a tethered [2Fe–2S] cluster have been synthesized and incorporated in conical helical foldamer sequences. Exploiting the modularity and predictability of aromatic oligoamide structures allowed for the straightforward design of a conical architecture able to sequester the metal complex in a confined environment. Even though no direct metal complex-foldamer interactions were purposely designed in this first generation model, crystallography, NMR and IR spectroscopy concurred to show that the aromatic oligoamide backbone alters the structure and fluxional processes of the metal cluster.

中文翻译：

---

芳香折叠体作为金属第二配位球设计的支架

以金属蛋白为例，金属中心的化学和物理性质不仅取决于它们的第一配位层，还取决于它们的第二配位层。因此，非常希望在合成金属配合物的第一配位球周围安装官能团阵列，但这仍然是一个具有挑战性的目标。在这里，我们介绍一种新方法来生成定制的第二协调球。我们使用基于芳香低聚酰胺折叠体的仿生人工架构，在金属复合物周围构建了一个刚性、模块化和明确的环境。具体来说，具有束缚的[2Fe-2S]簇的氮杂芳香族单体已被合成并整合到圆锥形螺旋折叠体序列中。利用芳香族低聚酰胺结构的模块化和可预测性，可以直接设计锥形结构，从而能够在有限的环境中隔离金属络合物。尽管在第一代模型中没有特意设计直接的金属络合物-折叠体相互作用，但晶体学、核磁共振和红外光谱一致表明，芳香族低聚酰胺主链改变了金属簇的结构和流动过程。