Video Experimental Relacionado
Updated: Jul 10, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
Los electrones correlacionados en el anión de Preyssler intercambiado por Eu [EuP ((5) W ((30) O ((110)) ] ((n-)
L Soderholm1, Mark R Antonio, S Skanthakumar
1Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA. ls@anl.gov
Journal of the American Chemical Society
|June 20, 2002
Resumen
El anión de Preyssler cifrado en Eu exhibe un comportamiento electrónico único, que sufre reducción con su marco. Este descubrimiento en un cúmulo aislado ofrece nuevas vías de investigación para sistemas de electrones correlacionados.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Ciencia de los materiales Ciencia de los materiales.
- La electroquímica es electroquímica.
Sus antecedentes:
- El anión de Preyssler ([EuP5W30O110]n-) es un grupo de polioxometalatos.
- Los iones lantánidos trivalentes como el La3+ pueden intercambiarse en la estructura aniónica de Preyssler.
- El anión padre de Preyssler es electroactivo, aceptando múltiples electrones.
Objetivo del estudio:
- Para investigar las propiedades electrónicas del anión de Preyssler cifrado en Eu.
- Comprender el mecanismo de reducción del europio (Eu) encapsulado.
- Para explorar el comportamiento potencial de electrones correlacionados en un cúmulo aislado.
Principales métodos:
- Espectroscopia de la estructura de absorción de rayos X cercana al borde (XANES) de europio L3-edge.
- Métodos electroquímicos que incluyen coulometría.
- Mediciones de la susceptibilidad magnética.
Principales resultados:
- El anión de Preyssler cifrado en Eu muestra propiedades electrónicas inusuales dependientes del potencial aplicado.
- El europio (Eu), inicialmente trivalente, se reduce junto con el marco de polioxometalato.
- La evidencia sugiere una interacción de enlace entre los estados Eu f y la banda marco de tungsteno-oxígeno (W-O).
Conclusiones:
- El mecanismo de reducción implica el marco Fermi de cruce a nivel de estados localizados de la UE.
- Este comportamiento se asemeja al observado en los sistemas de valentes intermedios y de electrones correlacionados.
- El estudio demuestra fenómenos de electrones correlacionados en un grupo aislado, abriendo nuevas direcciones de investigación.
Videos de Conceptos Relacionados
00:54Electron Behavior
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.Electrons Orbit the NucleusElectrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus...
03:26Electron Configuration of Multielectron Atoms
The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
03:07Electron Affinity
The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion).
02:46Electron Configurations
Electron configurations and orbital diagrams can be determined by applying the Aufbau principle (each added electron occupies the subshell of lowest energy available), Pauli exclusion principle (no two electrons can have the same set of four quantum numbers), and Hund’s rule of maximum multiplicity (whenever possible, electrons retain unpaired spins in degenerate orbitals).
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
01:27π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...
01:09Electron Behavior
Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...