Building Block and Directional Bonding Approaches for the Synthesis of {DyMn4}n (n=2, 3) Metallacrown Assemblies

Four 3d-4f heterometallic complexes based on salicylhydroxamic acid (H(3)sha) have been synthesized. Single-crystal X-ray diffraction analysis reveal that all complexes are comprised of {Dy[12-MCsha,Mn(III)-4]}(n) (n = 2 or 3, MC = metallacrown) supramolecular architectures, where the MC building blocks are further ligated by the ditopic subunit ligands with different lengths and bite angles. Along with the angular orientations ranging from 120 degrees to 180 degrees , the resulting architectures vary from dimeric double-layer to trimeric triangular MC assemblies based on the building block and directional bonding approaches. Magnetic measurements reveal the presence of dominant antiferromagnetic interactions for all complexes, thereinto, one of which displays slow relaxation of magnetization under external dc field.