Field-Induced Relaxation of Magnetization in a Three-Dimensional LnMOF with the Second Bridging Ligand Squarate

A three-dimensional (3D) dysprosium­(III) metal-organic framework with nicotinate N-oxide (NNO–) and squarate (C4O42–) mixed bridging ligands, [Dy­(NNO)­(C4O4)­(H2O)]n (1), has been hydrothermally synthesized. The dysprosium­(III) ions are linked to each other by the squarate anions to form a unique dysprosium­(III) squarate double-layered network; the NNO– anions then bridge such layers to complete the 3D framework. Complex 1 exhibits a two-step relaxation of magnetization under a dc field of 1000 Oe, with effective energy barrier values of 8.5 and 14.3 K, respectively.