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A new polyoxometalate of earth adundant elements [{Co(4)(μ-OH)(H(2)O)(3)}(Si(2)W(19)O(70))](11-) has been synthesized, characterized and shown to be a water oxidation catalyst. The initial catalytic complex is unstable and slowly undergoes hydrolysis. The hydrolysis products have been isolated and characterized, and their catalytic water oxidation activity is assessed.

Republication or reproduction of this report or its storage and/or dissemination by electronic means is permitted without the Practical guide to measurement and interpretation of magnetic properties (IUPAC Technical Report)Abstract: Rules are pointed out to protect the magnetochemist from pitfalls in both measurement and interpretation of magnetic data. Carefully chosen magnetic field strengths during magnetic susceptibility measurements guarantee the recording of genuine data. With the help of examples, the effect of too strong applied fields is demonstrated producing magnetic saturation and, for example, quenching of weak ferro-or antiferromagnetic spin-spin couplings. In consequence, the data run the risk of being misinterpreted unless model susceptibility equations are applied that take the field dependence of χ m into consideration. Recommendations are given for the presentation of experimental and theoretical data. The limited applicability of the most overworked formula in paramagnetism, the Curie-Weiss law χ m = C/(T-θ), is clearly presented (magnetically condensed systems, pure spin magnetism). While rough and ready susceptibility formulae are applicable to specific 3d and 4f systems, the complex situation for the remaining d and f centers, including actinides, demands computer programs which consider simultaneously interelectronic repulsion, ligand field potential, spin-orbit coupling, interatomic exchange interactions, and applied magnetic field.

The emergence of increasingly complex molecular magnets, driven in particular by polyoxometalate chemistry, requires theoretical tools to accurately model and understand their magnetic phenomena. At the same time the unambiguous verification of model Hamiltonians remains a challenge, tied to factors ranging from available independent experimental data sets to available computation resources. Focusing on several recent examples for magnetically functionalized polyoxometalates and polynuclear coordination complexes, we demonstrate the recent developments of CONDON 2.0 that aim to address these issues, and suggest measurement protocols that will aid our multi‐parameter computational approach.

Die Eigenschaften der Verbindungen [K‐([2.2.2]‐crypt)]3E9 mit isolierten Anionen E93– (E = Ge (1), Sn (2), Pb (3)) wurden EPR‐spektroskopisch bei Raumtemperatur und 77 K, magnetochemisch im Bereich von 2 K bis 300 K und cyclovoltammetrisch in Lösung untersucht. Die EPR‐Signale von Pulverproben und Einkristallen lassen sich mit drei g‐Tensorkomponenten beschreiben, was auf das Vorliegen von E93–‐Clustern mit Strukturen niedriger Symmetrie hindeutet. Die magnetischen Suszeptibilitäten von 2 und 3 folgen der Beziehung (χmol = C/(T – θp) + χ0 mit θp ≈ 0. Die Werte für C entsprechen einem Anteil von ungefähr 50% paramagnetischer Anionen E93– (S = 1/2). In Lösung beobachtet man für 2 und 3 irreversible oxidative Elektronenprozesse. Stromintensitäten und Peakform deuten an, dass unabhängig vom Material der Arbeitselektrode (Platin, Gold oder Glas‐Kohlenstoff) Adsorptionsprozesse eine wichtige Rolle spielen.