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

摘要

A novel macrocyclic hexanuclear iron(Ill) 18-azametallacrown-6 compound, [Fe-6(C9H7N2O3),(CH3OH)(6)].8CH(3)OH.2H(2)O, has been prepared using a trianionic pentadentate ligand N-acetylsalicylhydrazide (ashz(3-)) 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 Lambda/Delta forms. The disc-shaped hexanuclear ring shows about 6.20 Angstrom in diameter at entrance, about 9.31 Angstrom 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) Angstrom. The magnetic susceptibility (4-275K) study indicates antiferromagnetic exchange interactions between the adjacent Fe3+ ions around the ring. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 21]