The dissolution of anhydrous iron bromide in a mixture of pyridine and acetonitrile, in the presence of an organic amine, results in the formation of an [Fe34] metal oxide molecule, structurally characterised by alternate layers of tetrahedral and octahedral FeIII ions connected by oxide and hydroxide ions. The outer shell of the complex is capped by a combination of pyridine molecules and bromide ions. Magnetic data, measured at temperatures as low as 0.4 K and fields up to 35 T, reveal competing antiferromagnetic exchange interactions; DFT calculations showing that the magnitudes of the coupling constants are highly dependent on both the Fe‐O‐Fe angles and Fe−O distances. The simplicity of the synthetic methodology, and the structural similarity between [Fe34], bulk iron oxides, previous FeIII–oxo cages, and polyoxometalates (POMs), hints that much larger molecular FeIII oxides can be made.

C-alkylpyrogallol[4]arenes (PgCs) have been studied for their ability to form metal-organic nanocapsules (MONCs) through coordination to appropriate metal ions. Here we present the synthesis and characterization of an MnII/MnIII-seamed MONC in addition to its electrochemical and magnetic behavior. This MONC assembles from 24 manganese ions and 6 PgCs, while an additional metal ion is located on the capsule interior, anchored through the introduction of bridging nitrite ions. The latter originate from an in situ redox reaction that occurs during the self-assembly process, thus representing a new route to otherwise unobtainable nanocapsules.

A large family of chromium(III) dimers has been synthesised and magneto-structurally characterised using a combination of carboxylate and diethanolamine type ligands. The compounds have the general formula . Removal of the carboxylate to produce the dialkoxide-bridged compound 9 resulted in antiferromagnetic (AFM) exchange between the Cr(III) ions. DFT calculations reveal the ferromagnetic exchange is the result of an orbital counter-complementarity effect occuring upon introduction of the bridging carboxylate.

Under suitable conditions, C-alkylpyrogallol[4]arenes (PgCs) arrange into spherical metal-organic nanocapsules (MONCs) upon coordination to appropriate metal ions. Herein we present the synthesis and structural characterization of a novel Fe II /Fe III-seamed MONC, as well as studies related to its electrochemical and magnetic behaviors. Unlike other MONCs which are assembled through 24 metal ions, this nanocapsule comprises 32 Fe ions, uncovering 8 additional coordination sites situated between the constituent PgC sub-units. The Fe II ions are likely formed by the reducing ability of DMF used in the synthesis, representing a novel synthetic route towards polynuclear mixed-valence MONCs.

Two structurally analogous Mn-seamed C-alkylpyrogallol[4]arene (PgC )-based metal-organic nanocapsules (MONCs) have been synthesized under similar reaction conditions and characterized by crystallographic, electrochemical, and magnetic susceptibility techniques. Both MONCs contain 24 Mn centers, but, somewhat surprisingly, marked differences in oxidation state distribution are observed upon analysis. One MONC contains exclusively Mn ions, while the other is a mixed-valence Mn/ Mn assembly. We propose that these disparate oxidation state distributions arise from slight differences in pH achieved during synthesis, a factor that may lead to many spectacular new MONCs (and associated host-guest chemistries).