[ReF6]2−: A Robust Module for the Design of Molecule‐Based Magnetic Materials

A facile synthesis of the [ReF₆]^2? ion and its use as a building block to synthesize magnetic systems are reported. Using dc and ac magnetic susceptibility measurements, INS and EPR spectroscopies, the magnetic properties of the isolated [ReF₆]^2? unit in (PPh₄)₂[ReF₆]?2 H₂O ( 1 ) have been fully studied including the slow relaxation of the magnetization observed below ca. 4 K. This slow dynamic is preserved for the one‐dimensional coordination polymer [Zn(viz)₄(ReF₆)]_∞ ( 2 , viz=1‐vinylimidazole), demonstrating the irrelevance of low symmetry for such magnetization dynamics in systems with easy‐plane‐type anisotropy. The ability of fluoride to mediate significant exchange interactions is exemplified by the isostructural [Ni(viz)₄(ReF₆)]_∞ ( 3 ) analogue in which the ferromagnetic Ni^II–Re^IV interaction (+10.8 cm^?1) dwarfs the coupling present in related cyanide‐bridged systems. These results reveal [ReF₆]^2? to be an unique new module for the design of molecule‐based magnetic materials.     

New Classes of Ferromagnetic Materials with Exclusively End‐on Azido Bridges: From Single‐Molecule Magnets to 2 D Molecule‐Based Magnets

A new, flexible synthetic route, which does not require the co‐presence of any organic chelating/bridging ligand but only the “key” precursor Me₃SiN₃, has been discovered and led to a new class of inorganic materials containing exclusively end‐on azido bridges; the reported 3d‐metal clusters and coordination polymers exhibit ferromagnetic, single‐molecule magnet, and long‐range magnetic ordering properties.     

Inside Cover: Multicompartmental Microcylinders (Angew. Chem. Int. Ed. 25/2009)

Multicompartmental microcylinders can be produced by a combination of electrohydrodynamic co‐spinning and microsectioning, as described by J. Lahann et al. in their Communication on page 4589 ff. The number of individual compartments, relative compartment orientation, chemical composition and functionality, and aspect ratio can be precisely tuned. Each color in the longitudinal and cross‐sectional micrograph images depicts an individual compartment.

     

[Fe19] “Super‐Lindqvist” Aggregate and Large 3D Interpenetrating Coordination Polymer from Solvothermal Reactions of [Fe2(OtBu)6] with Ethanol

The syntheses, crystal structures, and physical properties of [HFe₁₉O₁₄(OEt)₃₀] and {Fe₁₁(OEt)₂₄}_∞ are reported. [HFe₁₉O₁₄(OEt)₃₀] has an octahedral shape. Its core with a central Fe metal ion surrounded by six μ₆‐oxo ligands is arranged in the rock salt structure. {Fe₁₁(OEt)₂₄}_∞ is a mixed‐valence coordination polymer in which Fe^III metal ions form three 3D interpenetrating (10,3)‐b nets. The arrangement of the Fe^III ions can also be compared to that of Si ions in α‐ThSi₂. Thus, the described structures are at the interface between molecular and solid‐state chemistry.