Ionothermal synthesis of a 3D dysprosium-1,4-benzenedicarboxylate framework based on the 1D rod-shaped dysprosium-carboxylate building blocks exhibiting slow magnetization relaxation

摘要

Ionothermal reaction of DyCl3·6H2O with 1,4-benzenedicarboxylic acid (H2BDC) in 1-ethyl-3-methylimidazolium bromide (EMIM-Br) leads to a novel compound {(EMIM)[Dy3(BDC)5]}_n (1). Compound 1 consists of the extraframework charge-balancing cation [EMIM]+ and the [Dy3(BDC)5]_n~(n-) anionic framework with hex topology. The 3D [Dy3(BDC)5]_n~(n-) framework is constructed from the 1D rod-shaped Dy-carboxylate secondary building unit wherein the 6-, 8-, and 9-coordinated Dy(III) ions are alternately arranged. Detailed static and dynamic magnetic analysis of 1 revealed that 1 exhibits a slow magnetic relaxation behavior typical of single-molecule magnets (SMMs). Compound 1 displays an anisotropic energy barrier of 39.3 K and a pre-exponential factor τ0 of 2.6 × 10~(-10) s in the presence of a direct-current field of 2 kOe.