Synthesis, crystal structure and bioactivity of a novel 18-metallacrown-6 [Mn6(H2O)6(abshz)6] · 36H2O

A novel 18-metallacrown-6 compound, [Mn6(H2O)6 (abshz)6] · 36H2O (abshz = N-acetyl-5-bromosalicylhydrazide), has been prepared and characterized. The crystal structure contains a neutral 18-membered metallacrown ring which is formed by the succession of six structural moieties of the type [Mn(III)–N–N]. Due to the meridional coordination, the ligand enforces the stereochemistry of the Mn3+ ions as a propeller configuration with alternating Λ/Δ forms. Antibacterial screening data showed that the complex has strong antimicrobial activity against Staphylococcus aureus, Escherichia coli and Bacillus subtilis.