Theoretical Study of the Magnetic Behavior of [Fe8] and [Fe16] Wheels

Rational serendipity: “undirected” synthesis of a large {MnIII10CuII5} complex from pre-formed MnII building blocks

Use of an aminopolyalcohol-based Mn^II complex in solvothermal Cu^II chemistry leads to a rare example of a high nuclearity heterometallic {MnIII10CuII5} system, in which four {Cu^II(H₁Edte)} units trap an inner {MnIII10Cu^II} oxide core.

Carboxylate free μ-oxo bridged ferric wheel with a record exchange coupling

An oxo-bridged, carboxylate free ‘ferric wheel’ was isolated with the molecular formula [FeIII8(μ-O)₄(L²⁻)₈] (1). The strength of antiferromagnetic interaction between the Fe(iii) ions is revealed by magnetic simulation (J₁ = −26.4 and J₂ = −170 cm⁻¹). The exchange value of −170 cm⁻¹ is the largest exchange value known for any homometallic or heterometallic wheels reported to date.

Theoretical Study of the Magnetic Behavior of Ferric Wheels

Calculations of exchange coupling constants (J) based on density functional theory for eight complete, nonmodeled ferric wheels have been performed, and a comparison with the values obtained from magnetic susceptibility data is presented. The calculated J values obtained with a generalized-gradient approximation (GGA) functional are in good agreement with the experiment probably because the inclusion of pseudopotentials partially compensates the overestimation of the spin delocalization. The magnetostructural correlation obtained shows a strong dependence of the exchange coupling on both the Fe-O-Fe bond angle and the Fe-O bond distance. This correlation holds for both the ferric wheels and the alkoxo-bridged Fe(III) dinuclear complexes reported in the literature.

Using tripodal alcohols to build high-spin molecules and single-molecule magnets

The combination of tripodal alcohols with paramagnetic 3d transition metal ions leads to the isolation of a host of new clusters, high spin molecules and single-molecule magnets ranging in nuclearity from two to thirty-two.