Homochiral Laminar Europium Metal–Organic Framework with Unprecedented Giant Dielectric Anisotropy

Abstract

Hydrothermal (deuteratothermal) reaction of L‐ethyl lactate (Lig‐Et) with Eu(ClO₄)₃⋅6 H₂O gives colorless block crystals of [Eu(Lig)₂(X₂O)₂][ClO₄] (1, X=H; 2, X=D) both of which possess a two‐dimensional laminar homochiral framework. Single‐crystal dielectric measurements reveal that 1 and 2 display a giant dielectric anisotropy approximately exceeding 100 and large isotopic effect with about 54 % enhancement along the a axis. Their ferroelectric features further confirm this respect. Crystal parameters: 1, C₆H₁₄ClO₁₂Eu, M_r=465.58, monoclinic, C₂, a=8.6786(6), b=8.3965(6), c=10.2153(7) Å, β=92.040(1)°, V=743.92(9) ų, Z=2, ρ_calcd=2.079 Mg m⁻³, R₁=0.0508, wR₂=0.1239, μ=4.448 mm⁻¹, S=1.043; Flack=0.04(5). 2: C₆H₁₀D₄ClO₁₂Eu, M_r=469.61, monoclinic, C₂, a=8.689(2), b=8.410(2), c=10.224(3) Å, β=92.057(4)°, V=746.7(3) ų, Z=2, ρ_calcd=2.089 Mg m⁻³, R₁=0.0465, wR₂=0.1150, μ=4.432 mm⁻¹, S=1.058; Flack=0.02(5).