Horii Yoji, Damjanović Marko, Ajayakumar M R, Katoh Keiichi, Kitagawa Yasutaka, Chibotaru Liviu, Ungur Liviu, Mas-Torrent Marta, Wernsdorfer Wolfgang, Breedlove Brian K, Enders Markus, Veciana Jaume, Yamashita Masahiro
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba Aoba-ku, Sendai, Miyagi, 980-8578, Japan.
Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Chemistry. 2020 Jul 14;26(39):8621-8630. doi: 10.1002/chem.202001365. Epub 2020 Jun 18.
Presented here is a comprehensive study of highly oxidized multiple-decker complexes composed of Tb and Cd ions and two to five phthalocyaninato ligands, which are stabilized by electron-donating n-butoxy groups. From X-ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl-shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was observed in +4e charged species. From paramagnetic H NMR studies on the resulting series of triple, quadruple and quintuple-decker complexes, ligand oxidation leads to a decrease in the magnetic anisotropy, as predicted from theoretical calculations. Unusual paramagnetic shifts were observed in the spectra of the +2e charged quadruple and quintuple-decker complexes, indicating that those two species are actually unexpected triplet biradicals. Magnetic measurements revealed that the series of complexes show single-molecule magnet properties, which are controlled by the multi-step redox induced structural changes.
本文展示了一项关于由铽（Tb）和镉（Cd）离子以及两到五个酞菁配体组成的高度氧化的多层配合物的综合研究，这些配合物由供电子的正丁氧基稳定。通过X射线结构分析，所有配合物在配体氧化时都会发生轴向压缩，导致配体呈碗状扭曲。此外，在带 +4e 电荷的物种中观察到金属离子周围存在不寻常的四方反棱柱和四方棱柱几何构型共存。通过对所得一系列三层、四层和五层配合物进行顺磁氢核磁共振研究，正如理论计算所预测的那样，配体氧化导致磁各向异性降低。在带 +2e 电荷的四层和五层配合物的光谱中观察到不寻常的顺磁位移，表明这两种物种实际上是意外的三重态双自由基。磁性测量表明，该系列配合物表现出单分子磁体性质，这些性质由多步氧化还原诱导的结构变化控制。
