Enantiopure Chiral Two-dimensional Sinusoidal Lanthanide(III) Coordination Polymers Based on R-/S-2-Methylglutarate: Luminescence, Magnetic Entropy Change, and Magnetic Relaxation

Abstract

As a base for neutralizing homochiral dicarboxylic acids [R-/S-2-methylglutaric acid, abbreviated as (R/S)-2-MG] rather than an N-donor ligand, 1,3-di(4-pyridyl)propane participates in the self-assembly of isostructural, homochiral lanthanide(III) coordination polymers derived from (R/S)-2-MG at room temperature, which show 2D sinusoidal ruffling (4, 4) network structures with the formulas {[Eu2(R-2-MG)3(H2O)4]·0.5H2O}n (Eu-R1), {[Gd2(R-2-MG)3(H2O)4]·0.5H2O}n (Gd-R2), {[Tb2(R-2-MG)3(H2O)4]·0.5H2O}n (Tb-R3), and {[Dy2(R-2-MG)3(H2O)4]·0.5H2O}n (Dy-R4) as well as {[Eu2(S-2-MG)3(H2O)4]·0.5H2O}n (Eu-S1), {[Gd2(S-2-MG)3(H2O)4]·0.5H2O}n (Gd-S2), {[Tb2(S-2-MG)3(H2O)4]·0.5H2O}n (Tb-S3), and {[Dy2(S-2-MG)3(H2O)4]·0.5H2O}n (Dy-S4). Among them, the europium(III) and terbium(III) compounds show solid fluorescent properties characteristic of lanthanide(III) ions, while the dysprosium(III) compound may exhibit magnetic relaxation. Furthermore, the magnetic entropy change or magnetocaloric effect of the gadolinium(III) c...