A Trinuclear Iron(III) Complex Containing the Semi‐Cubane [Fe 3 (μ 3 ‐O)] 7+ Core: Structural, Spectroscopic, Magnetic and Electrochemical Study

A trinuclear iron(III) oxo‐centered complex [Fe 3 (μ 3 ‐O)(3‐OCH 3 ‐salnec) 3 ]OH · 5H 2 O was synthesized and characterized as cluster containing the semi‐cubane [Fe 3 (μ 3 ‐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‐OCH 3 ‐salnecH 2 = 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‐OCH 3 ‐saloH 2 ), in the presence of sodium methoxide and Fe 3+ . 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.