Synthesis, crystal structure and magnetic properties of a novel manganese(III) cluster

A polydentate hydroxy-rich Schiff base ligand, derived from the condensation of 3,5-dibromo-2-hydroxybenzaldehyde and 2-ethanolamine, namely 3,5-dibromo- salicylidene-2-ethanolamine (H2L), reacts with Mn(ClO4)2, NaO2CPiv and NaOCH3 to give a novel hexanuclear complex [NaIMnIII5(μ3-O2−)(μ4-O2−)L4(O2CPiv)3)(ClO4)]·1.5CH3OH·0.25H2O (1). The complex has been characterized by IR, elemental analyses, crystal structural analyses, and magnetic studies. The core in complex 1 features one μ3-O2− atom, one μ4-O2− atom, four L2− ligands, three PivCO2− groups together with a ClO4− ion bridging five MnIII atoms and a NaI atom to form a distorted cubane extended at one face by an incomplete adamantane unit, which is an unprecedented structural type in Mn chemistry. The variable-temperature solid-state dc magnetic susceptibility studies in the 2–300 K range for complex 1 reveal the presence of overall antiferromagnetic intracluster interactions.