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Una familia de barras de manganeso: síntesis, estructuras y propiedades magnéticas
Gopalan Rajaraman1, Muralee Murugesu, E Carolina Sañudo
1Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
Journal of the American Chemical Society
|November 26, 2004
Resumen
Se sintetizaron y caracterizaron nuevos complejos de manganeso. El Complejo 1 exhibe un comportamiento magnético de una sola molécula, mostrando potencial para aplicaciones magnéticas avanzadas.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Ciencia de los materiales Ciencia de los materiales.
- Magnetoquímica es la Magnetoquímica.
Sus antecedentes:
- Los triángulos metálicos de valencia mixta son precursores de nuevos materiales magnéticos.
- Los ligandos tripodales como el 1,1,1-tris (((hidroximetil) etano (H(3) thme) y el 1,1,1-tris ((hydroxymethyl) propano (H(3) tmp) pueden formar estructuras complejas.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos complejos similares a varillas de manganeso.
- Para investigar las propiedades magnéticas de estos complejos, incluyendo el giro del estado fundamental y el comportamiento magnético.
Principales métodos:
- Reacción de triángulos de manganeso de valor mixto con ligandos trípodos en el acetonitrilo.
- Temperatura variable corriente continua (dc) mediciones de susceptibilidad magnética.
- Cálculos de la teoría funcional de la densidad (DFT).
- Ciclo de histeresis monocristalino y mediciones de relajación.
Principales resultados:
- Se sintetizó una familia de complejos similares a varillas de manganeso derivados de triángulos que comparten los bordes.
- El complejo 1 ([Mn{12}O{4}OH{2}PhCOO{12}Thme{4}Py{2}) muestra un estado básico de S = 7 y exhibe un comportamiento de imán de una sola molécula (SMM).
- El complejo 2 ([Mn(8) O(4) (((CH(3)) (((3) CCO(2)) (((10) ((thme) (((2) (((py) ((2))) tiene un estado de base S = 6.
- El complejo 3 ([Mn{7) O{2) }{PhCO{2) }{9) }{thme{2) }{py{3) }) tiene un estado de base S = 7.
- El complejo 4 ([Mn{6}{CH{3}{3}CCO{2}{8}{tmp}{2}{p}{2}{2}{2}{3}}) tiene un estado de base ajustado S = 3, con DFT que sugiere S = 4.
- El complejo 5 ([Mn{6}{CH{3}CO{2}{6}{thme}{2}{H{2}{tea}{2}}) no muestra un ajuste satisfactorio, con DFT que sugiere S = 0.
Conclusiones:
- Los complejos de manganeso sintetizados muestran diversas propiedades magnéticas.
- El Complejo 1 se identifica como un imán de una sola molécula, destacando su potencial para el magnetismo molecular.
- Las propiedades estructurales y magnéticas están influenciadas por la elección del ligando y la arquitectura del clúster de metales.
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