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Updated: May 7, 2026
Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
Triple-stranded ferric helices: a π-π interaction-driven structural hierarchy of Fe5, Fe7, and Fe17 clusters
Takuya Shiga1, Mao Noguchi, Hiroki Sato
1Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba 305-8571, Japan. oshio@chem.tsukuba.ac.jp.
Abstract:
Three polypyridine ligand-supported multinuclear iron complexes, [Fe5], [Fe7] and [Fe17], were synthesized and their physical properties were investigated. The complexes had triple-stranded helical structures with pseudo threefold symmetry, and were stabilized by varying degrees of intramolecular π-π stacking. The pentanuclear iron complex consisted of two Fe(II) and three Fe(III) ions, supported by three ligands, while the heptanuclear complex comprised four Fe(II) centres, three Fe(III) ions, and six ligands, and the heptadecanuclear complex contained seventeen Fe(III) ions and nine ligands. Electrochemical studies revealed that the pentanuclear and heptanuclear iron complexes showed pseudo-reversible three- and five-step redox behaviours, respectively. Magnetic measurements conducted on the pentanuclear and heptanuclear complexes revealed that antiferromagnetic interactions were operative between neighbouring iron ions through the oxo- and pyrazole-bridges.
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