2004 Volume 77 Issue 4 Pages 733-739
A tetranucleating macrocyclic ligand with four endogenous phenolic groups is obtained by the condensation of 3-aminomethyl-5-methylsalicylaldehyde in the presence of metal ion as two tetranuclear NiII complexes, [Ni4(L)(OH)(H2O)4](ClO4)3 (1) and [Ni4(L)(O)(dmf)4](ClO4)2 (2), and a dinuclear MnIII complex, [Mn2(H2L)(OH)(AcO)2(H2O)]Br (3). X-ray crystallographic studies for [Ni4(L)(OH)(H2O)8](ClO4)3·7H2O (1′) indicate that the macrocyclic ligand accommodates four NiII ions, producing a square Ni4 core with μ4-hydroxo group at the center of the core. Water molecules occupy the axial sites of each Ni affording a nearly octahedral geometry about the metal. Complex 2 has a similar tetranuclear Ni4-core possessing a μ4-oxo group at the center of the core. In complex 3, the di-protonated ligand (H2L)2− accommodates two MnIII ions, affording a (μ-hydroxo)(μ-acetato)dimanganese(III) core. Magnetic studies for 1 and 2 indicate a ferromagnetic interaction between the adjacent NiII centers and an antiferromagnetic interaction between the diagonal NiII centers. Complex 3 shows a weak antiferromagnetic interaction between the two MnIII ions.
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