Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan.
Nat Chem. 2011 Nov 20;4(1):52-8. doi: 10.1038/nchem.1202.
Sandwich structures formed by metal atoms intercalated between sp(2)-carbon planes can be found either in metal-graphite-based materials or discrete multinuclear sandwich complexes. Their reactivity, and in particular their dynamic behaviour, has recently attracted interest both from a structural and a practical aspect, for example in catalysis. However, progress in this area has been rather slow, and it remains difficult to elucidate their structure and behaviour at the molecular level. Here, we report two sandwich complexes--in which four palladium centres are incorporated between two π-conjugated ligands--which exhibit two modes of redox-switchable structural changes. In the first complex, the tetrapalladium chain is split by oxidation into two well-separated dipalladium units. This motion is reversed on reduction. In the second complex, reversible carbon-carbon coupling occurs between the ligands during the redox process.
夹层结构由金属原子插在 sp(2)-碳平面之间形成，可以在金属-石墨基材料或离散多核夹层复合物中找到。它们的反应性，特别是它们的动态行为，最近从结构和实际方面引起了兴趣，例如在催化方面。然而，这一领域的进展相当缓慢，仍然难以在分子水平上阐明其结构和行为。在这里，我们报告了两个夹层复合物，其中四个钯中心被嵌入两个π共轭配体之间，它们表现出两种氧化还原开关结构变化模式。在第一个复合物中，四钯链通过氧化分裂成两个完全分离的二钯单元。这种运动在还原时会反转。在第二个复合物中，在氧化还原过程中配体之间发生可逆的碳-碳偶联。
