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A novel cross-net-shaped metallamacrocycle, [ Mn 10 III Mn 4 II ( L ) 8 ( HL ) 2 ( H 2 O ) 2 ( CH 3 OH ) 14 ] · 8 H 2 O · 8 CH 3 OH (H4L = (Z)-3-(salicylhydrazinocarbonyl) propenoic acid), has been prepared and characterized. The crystal structure contains seven crystallographically unique manganese ions, in which two opening 13-membered metallacrown rings and two strands, Mn–N–N–Mn, are bridged by eight μ-maleoyl groups. The high nuclearity of the molecule shows large magnetic moments, with the value of μeff at 300 K is 19.01 μB.

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.