Novel 18-membered hexanuclear metallamacrocycle: Synthesis, crystal structure, and magnetic properties

The novel 18-metallacrown-6 metallamacrocycle, with the formula of [Mn6(amshz)6(CH3OH)6]·6H2O (amshz = N-acetyl-3-methyl-salicylhydrazide), has been prepared and characterized. Six Mn(III) ions and six deprotonated N-acetyl-3-methyl-salicylhydrazide (amshz3−) ligands construct a planar 18-membered ring based on Mn–N–N–Mn linkage. Due to the coordination, the ligand enforces the stereochemistry of the Mn3+ ions as a propeller shape with alternating …ΔΛΔΛ… configurations. The magnetic properties of the metallacrown molecules are characterized by a weak antiferromagnetic exchange interaction, with μeff = 5.12 μB at 300 K between the Mn3+ ion spins with S = 2 in the cyclic system.