A Trinuclear Iron(III) Complex Containing the Semi-Cubane [Fe3(μ3-O)]7+ Core: Structural, Spectroscopic, Magnetic and Electrochemical Study

A trinuclear iron(III) oxo‐centered complex [Fe3(μ3‐O)(3‐OCH3‐salnec)3]OH·5H2O was synthesized and characterized as cluster containing the semi‐cubane [Fe3(μ3‐O)]7+ core. The central oxygen atom is bridging the three iron(III) ions, which form an equilateral triangle with an average edge of –3.00 Å as it was deduced from X‐ray diffraction studies. The new tetradentate ligand 3‐OCH3‐salnecH2 = 1‐[1‐hydroxy‐2‐(9′‐methyl‐1,10′‐phenanthrolin‐2‐yl)ethyl]‐3‐methoxyphenol‐2, was generated “in situ” during the synthesis process as a product of the addition reaction between the starting ligands 2,9‐dimethyl‐phenanthroline(neoc) and 3‐methoxy‐salicylaldehyde(3‐OCH3‐saloH2), in the presence of sodium methoxide and Fe3+. Variable‐temperature magnetic measurements indicate antiferromagnetic exchange interactions between the iron(III) ions in the cluster. Additionally, spectroscopic (IR, UV/Vis, Mössbauer, EPR) and electrochemical studies (CV) are presented and discussed.