Slow relaxation of magnetization in a bis-mer-tridentate octahedral Co(II) complex
Reaction of a rigid tridentate ligand o-[(1H-imidazol-2-yl)methylideneamino]phenol (2-H(2)imap) with Co(ClO4) in the presence of NaN3, or Co(NO3)(2) without a base yields [Co-II(2-Himap)(2)] 1 and [Co-III(2-Himap) (2)]NO3 center dot MeOH2, respectively. Both complexes exhibit a mer-octahedral geomet...
| Autores: | , , , , , , , , |
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| 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:2445/142923 |
| Acceso en línea: | https://hdl.handle.net/2445/142923 |
| Access Level: | acceso abierto |
| Palabra clave: | Propietats magnètiques Lligands (Bioquímica) Magnetic properties Ligands (Biochemistry) |
| Sumario: | Reaction of a rigid tridentate ligand o-[(1H-imidazol-2-yl)methylideneamino]phenol (2-H(2)imap) with Co(ClO4) in the presence of NaN3, or Co(NO3)(2) without a base yields [Co-II(2-Himap)(2)] 1 and [Co-III(2-Himap) (2)]NO3 center dot MeOH2, respectively. Both complexes exhibit a mer-octahedral geometry with the cobalt centre being distorted along an octahedral-trigonal prismatic pathway. The packing in 1 and 2 is dominated by H-bonding forming 2D sheets and 1D chains, respectively. Detailed dc and ac magnetic studies indicate that 1 is a field-induced single-ion magnet (SIM) with D = 36.7 cm(-1) and E = 2.0 cm(-1). Extensive ab initio calculations support these conclusions and suggest that relaxation of the magnetization occurs principally through direct quantum tunnelling in the ground state, with the Raman process dominant in an applied field. This contrasts with the recently reported series of mer-[Co(L)(2)] (L = monoanionic NNO donor ligand; Inorg. Chem., 2017, 56, 6056-6066) complexes where D is negative, as these compounds have a more ambiguous geometry, and highlights the importance of supramolecular interactions in subtly altering the coordination sphere thereby impacting the magnetic behaviour. |
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