An unprecedented zigzag-shaped heptanuclear ferric cluster: synthesis, structure and magnetism

• A novel Fe7 complex derived from a Schiff base ligand has been synthesized.
• The complex contains an unprecedented zigzag arrangement heptanuclear Fe7 unit.
• Magnetic study of Fe7 unit confirmed the strong magnetostructural correlation.
• The J value is related with the average FeO distance and the FeOFe angle.

The synthesis, crystal structure and magnetochemical characterization are reported for a new FeIII7 cluster, [FeIII7(L)4(O2CPh)8(H2O)2]NO3·3CH3CN (1). Complex 1 was synthesized from the use of the potentially O,N,O,O tetradentate chelate, 3-(2-hydroxybenzylideneamino)propane-1,2-diol (H3L), in the presence of carboxylate groups. Inspection of the central core reveals that it contains two triangular subunits sharing a common vertex Fe2, and then the vertex Fe3 (Fe3A) is further bonded to Fe4 (Fe4A) by a μ2-Oalkoxide atom from the L3 − ligand, generating the unprecedented zigzag arrangement heptanuclear Fe7 unit. Variable temperature magnetic susceptibility studies for 1 reveal the presence of only antiferromagnetic exchange interactions. Complex 1 shows no evidence of slow relaxation behavior above 2.0 K.

A novel heptanuclear ferric complex, containing an unprecedented zigzag arrangement Fe7 unit, has been obtained. Magnetic behavior indicates that only antiferromagnetic exchange interactions are present in the Fe7 cluster.Figure optionsDownload as PowerPoint slide