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Updated: Apr 5, 2026
Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
Synthesis of well-defined bicapped octahedral iron clusters [((tren) L)2 Fe8 (PMe2 Ph)2 ](n) (n=0, -1)
Raúl Hernández Sánchez1, Alexander M Willis1, Shao-Liang Zheng1
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St. Cambridge, MA, 02138 USA.
Abstract:
The synthesis of polynuclear clusters with control over size and cluster geometry remains an unsolved challenge. Herein, we report the synthesis and characterization of open-shell octairon clusters supported by two heptaamine ligands [o-H2 NC6 H4 NH(CH2 )2 ]3 N ((tren) LH9 ). The crystal structure of the all-ferrous species ([(tren) L)2 Fe8 (PMe2 Ph)2 ] (1) displays a bicapped octahedral geometry with FeFe distances ranging from 2.4071(6) to 2.8236(5) Å, where the ligand amine units are formally in amine, amide, and imide oxidation states. Several redox states of the octairon cluster are accessible, as ascertained using cyclic voltammetry. The one-electron-reduced clusters [M](+) [((tren) L)2 Fe8 (PMe2 Ph)2 ](-) (M=Bu4 N (2 a); (15-crown-5)Na(thf) (2 b)) were isolated and characterized. Variable-temperature magnetic susceptibility data indicates that the exchange coupling within the [Fe8 ] core is antiferromagnetic which is attenuated upon reduction to the mixed valent anion.
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