近日，同济大学韩海祥团队重温了经典的[Fe₄S₄（SR）₄]^2-分子团簇：配体的空间效应及其结构转变。2025年7月8日，《结构化学》杂志发表了这一成果。

合成的具有立方[4Fe-4S]核心的分子簇已经研究了几十年，因为它们是生物系统中铁蛋白活性成分的真正类似物。这种模型簇在各个领域得到了广泛的研究，包括结构调节、催化和实验室条件下的自组装，目的是深入了解它们在生物功能中的作用。研究组重新审视了三种众所周知的[Fe₄S₄（SR）₄]^2-分子，即[Me₄N]₂[Fe₄S（SR）₄]（R=o-MBT，m-MBT，p-MBT），并成功地建立了其在这项工作之前未知的单晶结构。

有趣的是，研究组发现取代基甲基的位置对[4Fe-4S]核周围配体的排列有明显的空间效应，这进一步影响了它们在单晶中的整体堆积模式。此外，这项工作揭示了[Fe₄S₄（SR）₄]^2-体系两种新的结构转变行为：i）单体[Fe（SR）₄]^2-和四聚体[Fe₄S₄（SR）₄]^2-可以相互转化，ii）[Fe₄S₄]^2-可以在良好控制的氧化环境中转化为有趣的氧化铁络合物Na₂Fe₆O（OMe）₁₈·6MeOH。

附：英文原文

Title: Revisit the classical [Fe4S4(SR)4]2- molecular clusters: The steric effects of ligands and their structural transformations

Author: anonymous

Issue&Volume: 2025-07-08

Abstract: The synthesized molecular clusters featuring the cubic [4Fe-4S] core have been studied for several decades, as they serve as true analogs of the active components in ferritin within biological systems. Such a model cluster has been extensively investigated in various fields, including structural modulation, catalysis, and self-assembly under laboratory conditions, with the aim of gaining an in-depth understanding of their roles in biological functions. Herein, we revisited three well-known [Fe4S4(SR)4]2- molecules, namely [Me4N]2[Fe4S4(SR)4] (R = o-MBT, m-MBT, p-MBT), and successfully established their single crystal structures that remain unknown prior to this work. Interestingly, it was revealed that the position of the substituent methyl group has an obvious steric effect on the arrangement of the ligand around the [4Fe-4S] core, which further influences their overall packing patterns in single crystals. In addition, this work unveils two new structure transformation behaviors for the [Fe4S4(SR)4]2- system: i) the monomeric [Fe(SR)4]2- and tetrameric [Fe4S4(SR)4]2- can be interconverted, and ii) [Fe4S4(SR)4]2- can be transferred into an intriguing iron-oxide complex Na2Fe6O(OMe)18·6MeOH in a well-controlled oxidizing environment.

DOI: 10.1016/j.cjsc.2025.100660

Source: https://cjsc.ac.cn/cms/issues/839