The Versatility of Ethylene Glycol to Tune the Dimensionality and Magnetic Properties in Dy<sup>III</sup>-Anilato-Based Single-Ion Magnets
Samia Benmansour, Cristina Pintado‐Zaldo, Javier Martínez‐Ponce, Antonio Hernández-Paredes, Antonio Valero-Martínez, Miriam Gómez-Benmansour, Carlos J. Gómez‐García
Abstract
High Resolution Image Download MS PowerPoint Slide We exploit the high versatility of the solvent ethylene glycol (eg = CH 2 OH-CH 2 OH) acting as a ligand with three different coordination modes: terminal (κ O ), chelate (κ 2 O,O′ ), and bridge (1κ O,2κ O′ ) to prepare a novel family of six different coordination polymers with Dy III and three different anilato ligands (3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone dianion = C 6 O 4 X 2 2–, with X = H, Cl, and Br). With the X = H derivative (dhbq 2– ), we have prepared [Dy 2 (dhbq) 3 (eg) 2 (μ-eg)]·4eg·2H 2 O ( 1 ), a 3D diamond-like network with a chelate and bridging eg molecules. With the X = Cl derivative (chloranilato), we have prepared [Dy 2 (C 6 O 4 Cl 2 ) 3 (eg) 4 ]·2eg·H 2 O ( 2 ) and [Dy 2 (C 6 O 4 Cl 2 ) 3 (μ-eg)(H 2 O) 4 ]·2eg·7H 2 O ( 3 ). Compound 2 has a 2D (6,3)-gon brick-wall lattice and contains a chelate and a terminal eg molecule. Compound 3 has a 3D diamond-like topology as 1, although now the chelate eg has been replaced by two water molecules. Finally, with the X = Br derivative (bromanilato), we have obtained [Dy 2 (C 6 O 4 Br 2 ) 3 (eg) 2 (CH 3 OH) 2 ]·2eg·4CH 3 OH ( 4 ), [Dy 2 (C 6 O 4 Br 2 ) 3 (eg) 4 ]·4eg ( 5 ), and [Dy 2 (C 6 O 4 Br 2 ) 3 (eg) 3 (H 2 O)]·2eg·H 2 O ( 6 ). Compound 4 has a 2D (6,3)-gon herringbone topology and contains a chelate eg and a MeOH molecule. Compounds 5 and 6 have a 2D (6,3)-gon brick-wall topology with a chelate and a terminal eg molecules (in 5 and in one of the two independent Dy centers of 6 ). The other Dy center in 6 has a chelate eg and a water molecule. All the compounds show slow relaxation of the magnetization at low temperatures (in compounds 1, 2, and 5 with no applied DC field). The magnetization of compounds 1 – 6 relaxes through Orbach and direct mechanisms when a DC field is applied and through an Orbach and/or quantum tunneling mechanism when no DC field is applied.