Indirect Effect of the Hydrogen Bonds on the Magnetic Coupling on Dinuclear Mn(III) Compounds

The MnIJIII) dinuclear compounds [{MnIJbpy)IJH2O)}IJμ-2,6-Cl2C6H3COO)2IJμ-O){MnIJbpy)IJX)}]X, where X = ClO4 (1) or X = NO3 (2), were synthesised and characterised by X-ray diffraction spectroscopy. In both cases there were hydrogen bond interactions between the aqua ligand and counteranions, but with diff...

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Detalles Bibliográficos
Autores: Pagès Casas, Josep M., Escriche Tur, Luis, Font Bardia, Ma. Mercedes, Aullón López, Gabriel, Corbella i Cordomí, Montserrat
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:2445/162901
Acceso en línea:https://hdl.handle.net/2445/162901
Access Level:acceso abierto
Palabra clave:Cristal·lografia
Manganès
Magnetisme
Crystallography
Manganese
Magnetism
Descripción
Sumario:The MnIJIII) dinuclear compounds [{MnIJbpy)IJH2O)}IJμ-2,6-Cl2C6H3COO)2IJμ-O){MnIJbpy)IJX)}]X, where X = ClO4 (1) or X = NO3 (2), were synthesised and characterised by X-ray diffraction spectroscopy. In both cases there were hydrogen bond interactions between the aqua ligand and counteranions, but with different connectivity patterns. For compound 1, the interactions connected two dinuclear complexes through two perchlorate counteranions to generate a tetranuclear unit. For compound 2, the hydrogen bond was 'intramolecular' between the cationic complex, nitrate counteranion and crystallization water (Mn-LW⋯NO3 −⋯H2O⋯LN-Mn). This unusual interaction was responsible for the perfect orthogonality of the coordination octahedra on the dinuclear entity and noticeable elongation of these polyedra. Both compounds showed antiferromagnetic coupling, which was unusually strong for compound 2 with a nitrate anion (J = −9.2 and −27.3 cm−1 for 1 and 2, respectively) (H = −J·S1·S2). The effect of the counteranion (X) on the magnetic interaction was analysed by density functional theory studies. For both compounds, hydrogen bonds between the aqua ligand and counteranions weakened the antiferromagnetic interaction. Moreover, for 2, replacement of the counteranion nitrate with other groups had a significant effect on the magnetic interaction.