Synthesis, crystal structure and magnetic properties of a novel iron(III) 18-azametallacrown-6 compound

A novel macrocyclic hexanuclear iron(III) 18-azametallacrown-6 compound, [Fe6(C9H7N2O3)6(CH3OH)6]·8CH3OH·2H2O, has been prepared using a trianionic pentadentate ligand N-acetylsalicylhydrazide (ashz3−) and characterized by X-ray diffraction. Due to the meridional coordination of the ligand to the Fe3+ ion, the ligand enforces the stereochemistry of the Fe3+ ions as a propeller configuration with alternating Λ/Δ forms. The disc-shaped hexanuclear ring shows about 6.20 Å in diameter at entrance, about 9.31 Å at its largest diameter at the center of the cavity, respectively. There are many kinds of intramolecular and intermolecular hydrogen bonds in the title compound. The OH⋯O hydrogen bond distances range from 2.609(5)–2.901(5) Å. The magnetic susceptibility (4–275K) study indicates antiferromagnetic exchange interactions between the adjacent Fe3+ ions around the ring.