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Las densidades de espín en un compuesto de cadena bimetálica ferromagnética: difracción de neutrones polarizada y

Béatrice Gillon¹, Corine Mathonière, Eliseo Ruiz

¹Laboratoire Léon Brillouin (CEA-CNRS), CEN Saclay, 91191 Gif-sur-Yvette, France.

Journal of the American Chemical Society

|November 28, 2002

Resumen

Se estudió la distribución del espín en las cadenas [MnNi(NO2)4(en)2] utilizando difracción de neutrones polarizada y DFT. Los resultados muestran una mayor deslocalización de espín de Ni debido a los enlaces covalentes Ni-N, consistente entre el experimento y la teoría.

Área de la Ciencia:

Química Inorgánica La Química Inorgánica es la química inorgánica.
Química del estado sólido.
El magnetismo es el magnetismo.

Sus antecedentes:

Los compuestos de cadena hetero-bimetálicos ofrecen propiedades magnéticas únicas.
La comprensión de la distribución de espín es crucial para el diseño de imanes moleculares.

Objetivo del estudio:

Para investigar la distribución de la población de espín en las cadenas acopladas ferromagnéticamente [MnNi(NO2) 4 ((en) 2].
Para comparar resultados experimentales con cálculos teóricos.

Principales métodos:

Experimentos de difracción de neutrones polarizados.
Cálculos de la teoría funcional de la densidad (DFT) utilizando modelos moleculares dinucleares.

Principales resultados:

Las distribuciones de espín experimentales y teóricas son consistentes.
Se observó una mayor deslocalización de espín de los átomos de Ni debido a más enlaces covalentes Ni-N.
Distribución de espín isotrópica para el Mn (II) y anisotrópica para el Ni (II).

Conclusiones:

El acoplamiento ferromagnético débil Mn(II) -Ni(II) surge de la deslocalización del espín.
La superposición débil entre los orbitales magnéticos en Ni y Mn, con una deslocalización limitada del ligando, explica el mecanismo de acoplamiento.

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