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

Abstract

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]_nⁿ⁻ anionic framework with hex topology. The 3D [Dy₃(BDC)₅]_nⁿ⁻ 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.