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Un agregado supramolecular de cuatro imanes de una sola molécula con sesgo de intercambio
Tu N Nguyen1, Wolfgang Wernsdorfer, Khalil A Abboud
1Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
Journal of the American Chemical Society
|December 6, 2011
Resumen
Este estudio detalla la síntesis de un nuevo tetramero supramolecular a base de manganeso. Este complejo exhibe un comportamiento magnético de una sola molécula, mostrando el túnel cuántico de la magnetización.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Magnetoquímica es la Magnetoquímica.
Sus antecedentes:
- Los cúmulos de manganeso-oxígeno son de interés por sus propiedades magnéticas.
- Los imanes de una sola molécula (SMM) son unidades moleculares que exhiben histeresis magnética.
Objetivo del estudio:
- Para sintetizar y caracterizar un nuevo complejo supramolecular de manganeso.
- Para investigar las propiedades magnéticas y el comportamiento SMM del complejo sintetizado.
Principales métodos:
- Reacción de 3-fenil-1,5-bis (((piridina-2-il) pentano-1,5-diona dioxima (pdpdH ((2)) con un precursor triangular [Mn ((III) ((3) O (((O ((2)) CMe (((py)) ((3)) ((ClO ((4)))) El precursor triangular [Mn ((III) ((3) O (((2) CMe (((py)))) es un precursor triangular de 3-fenil-1,5-bis (((pyridin-2-il) pentano-1,5-diona dioxima (pdpdH ((2)) y el precursor triangular [Mn ((III) ((3) O (((2) CMe (((py)))) es un precursor triangular de [Mn ((III) ((3) O (((2) CMe (((py)))) es un precursor triangular.
- Mediciones de susceptibilidad magnética de estado sólido dc y ac.
- Magnetización versus barridos de campo dc en un solo cristal.
Principales resultados:
- Se sintetizó un tetrámero supramolecular rectangular, [Mn(12) O(4) ((O(2) CMe) ((12) ((pdpd) ((6)) ] ((ClO(4)) ((4) (3)), el cual fue sintetizado.
- El complejo 3 comprende cuatro unidades triangulares [Mn(3) O] ((7+) unidas por ligandos de dioximatos.
- Se identificaron cuatro imanes de una sola molécula (SMM) de Mn3) con un estado fundamental de S = 6 dentro del tetramer.
- Los bucles de histeresis por debajo de 1 K confirmaron el túnel cuántico sesgado por intercambio de la magnetización.
Conclusiones:
- El complejo sintetizado es un agregado supramolecular de cuatro unidades SMM de intercambio débilmente acopladas.
- El estudio demuestra la formación de ensamblajes SMM complejos a través del enlace covalente de unidades SMM más pequeñas.
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