The coordination sphere of the Fe(II) terpyridine complex 1 is rigidified by fourfold interlinking of both terpyridine ligands. Profiting from an octa‐aldehyde precursor complex, the ideal dimensions of the interlinking structures are determined by reversible Schiff‐base formation, before irreversible Wittig olefination provided the rigidified complex. Reversed‐phase HPLC enables the isolation of the all‐trans isomer of the Fe(II) terpyridine complex 1, which is fully characterized. While temperature independent low‐spin states were recorded with superconducting quantum interference device (SQUID) measurements for both, the open precursor 8 and the interlinked complex 1, evidence of the increased rigidity of the ligand sphere in 1 was provided by proton T₂ relaxation NMR experiments. The ligand sphere fixation in the macrocyclized complex 1 even reaches a level resisting substantial deformation upon deposition on an Au(111) surface, as demonstrated by its pristine form in a low temperature ultra‐high vacuum scanning tunneling microscope experiment.

中文翻译：

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笼中铁：通过四重互连固定 Fe(II)tpy2 复合物。

Fe(II) 三联吡啶配合物1的配位层通过两个三联吡啶配体的四重互连而刚性化。受益于八醛前体络合物，在不可逆维蒂希烯化提供刚性络合物之前，互连结构的理想尺寸由可逆希夫碱形成决定。反相 HPLC 能够分离Fe(II) 三联吡啶络合物1的全反式异构体，并对其进行了充分表征。虽然超导量子干涉装置 (SQUID) 测量记录了开放前体8和互连配合物1 的与温度无关的低自旋态，但质子 T ₂弛豫 NMR提供了1中配体球体刚性增加的证据实验。大环化配合物1中的配体球固定甚至达到了在Au(111)表面沉积时抵抗显着变形的水平，正如低温超高真空扫描隧道显微镜实验中其原始形式所证明的那样。