Field-Induced Slow Magnetic Relaxation in Co<sup>II</sup> Cyclopropane-1,1-dicarboxylates
oleh: Anna K. Matyukhina, Ekaterina N. Zorina-Tikhonova, Alexander S. Goloveshkin, Konstantin A. Babeshkin, Nikolay N. Efimov, Mikhail A. Kiskin, Igor L. Eremenko
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2022-10-01 |
Deskripsi
New Co<sup>II</sup> substituted malonate field-induced molecular magnets {[Rb<sub>6</sub>Co<sub>3</sub>(cpdc)<sub>6</sub>(H<sub>2</sub>O)<sub>12</sub>]∙6H<sub>2</sub>O}<i><sub>n</sub></i> (<b>1</b>) and [Cs<sub>2</sub>Co(cpdc)<sub>2</sub>(H<sub>2</sub>O)<sub>6</sub>]<i><sub>n</sub></i> (<b>2</b>) (where cpdc<sup>2−</sup> stands for cyclopropane-1,1-dicarboxylic acid dianions) were synthesized. Both compounds contain mononuclear bischelate fragments {Co<sup>II</sup>(cpdc)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}<sup>2</sup><sup>−</sup> where the quasi-octahedral cobalt environment (CoO<sub>6</sub>) is complemented by water molecules in apical positions. The alkali metal atoms play the role of connectors between the bischelate fragments to form 3D and 2D polymeric structures for <b>1</b> and <b>2</b>, respectively. Analysis of dc magnetic data using the parametric Griffith Hamiltonian for high-spin Co<sup>II</sup> supported by <i>ab initio</i> calculations revealed that both compounds have an easy axis of magnetic anisotropy. Compounds <b>1</b> and <b>2</b> exhibit slow magnetic relaxation under an external magnetic field (H<i><sub>DC</sub></i> = 1000 and 1500 Oe, respectively).