Influence of the disposition of the anisotropy axes into the magnetic properties of Mn-III dinuclear compounds with benzoato derivative bridges
The two new Mn-III dinudear compounds [{Mn-(H2O)(phen)}(2)(mu-4-CH3C6H4COO)(2)(mu-O)](ClO4)(2)center dot 3CH(3)CN center dot H2O (1.3CH(3)CN center dot H2O) and [{Mn(H2O)(phen)}(mu-O)](mu-2-BrC6H4COO)(2){Mn(NO3)(phen)}]NO3 (2) have been synthesized. Their structural data reveal significant differenc...
| Autores: | , , , , |
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| Formato: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2017 |
| País: | España |
| Recursos: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/154604 |
| Acesso em linha: | https://hdl.handle.net/2445/154604 |
| Access Level: | acceso abierto |
| Palavra-chave: | Manganès Lligands Difracció de raigs X Manganese Ligands X-rays diffraction |
| Resumo: | The two new Mn-III dinudear compounds [{Mn-(H2O)(phen)}(2)(mu-4-CH3C6H4COO)(2)(mu-O)](ClO4)(2)center dot 3CH(3)CN center dot H2O (1.3CH(3)CN center dot H2O) and [{Mn(H2O)(phen)}(mu-O)](mu-2-BrC6H4COO)(2){Mn(NO3)(phen)}]NO3 (2) have been synthesized. Their structural data reveal significant differences in the shape of the coordination octahedron around the Mn-III ions in both compounds. The different distortions from ideal geometry incite a very different magnetic behavior, affecting both the zero-field splitting parameters of the Mn-III ions (D-Mn and E-Mn) and the magnetic interaction between them. Compound 1, with elongation in the monodentate ligand direction, shows antiferromagnetic coupling (ground state S = 0) and local D-Mn < 0, while compound 2, with compression in the oxo bridge direction, displays a ferromagnetic interaction (ground state S = 4) and local D-Mn > 0. Theoretical CASSCF and DFT calculations corroborate the different magnetic anisotropy and exchange coupling found in both compounds. Moreover, with the help of theoretical calculations, some interesting magneto-structural correlations have been found between the degree of distortion of the coordination octahedra and the magnetic coupling; it becomes more antiferromagnetic when the elongation parameter, Delta, in absolute value is increased. |
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