A Pseudo-Octahedral Cobalt(II) Complex with Bispyrazolylpyridine Ligands Acting as a Zero-Field Single-Molecule Magnet with Easy Axis Anisotropy
The homoleptic mononuclear compound [Co(bpp‐COOMe)2](ClO4)2 (1) (bpp‐COOMe=methyl 2,6‐di(pyrazol‐1‐yl)pyridine‐4‐carboxylate) crystallizes in the monoclinic C2/c space group, and the cobalt(II) ion possesses a pseudo‐octahedral environment given by the two mer‐coordinated tridentate ligands. Direct‐...
| Autores: | , , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2018 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/142929 |
| Acceso en línea: | https://hdl.handle.net/2445/142929 |
| Access Level: | acceso abierto |
| Palabra clave: | Anisotropia Lligands (Bioquímica) Propietats magnètiques Anisotropy Ligands (Biochemistry) Magnetic properties |
| Sumario: | The homoleptic mononuclear compound [Co(bpp‐COOMe)2](ClO4)2 (1) (bpp‐COOMe=methyl 2,6‐di(pyrazol‐1‐yl)pyridine‐4‐carboxylate) crystallizes in the monoclinic C2/c space group, and the cobalt(II) ion possesses a pseudo‐octahedral environment given by the two mer‐coordinated tridentate ligands. Direct‐current magnetic data, single‐crystal torque magnetometry, and EPR measurements disclosed the easy‐axis nature of this cobalt(II) complex, which shows single‐molecule magnet behavior when a static field is applied in alternating‐current susceptibility measurements. Diamagnetic dilution in the zinc(II) analogue [Zn(bpp‐COOMe)2](ClO4)2 (2) afforded the derivative [Zn0.95Co0.05(bpp‐COOMe)2](ClO4)2 (3), which exhibits slow relaxation of magnetization even in zero field thanks to the reduction of dipolar interactions. Theoretical calculations confirmed the overall electronic structure and the magnetic scenario of the compound as drawn by experimental data, thus confirming the spin‐phonon Raman relaxation mechanism, and a direct quantum tunneling in the ground state as the most plausible relaxation pathway in zero field. |
|---|