Video Experimental Relacionado
Updated: Aug 3, 2026
11:04
Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
Estudios teóricos sobre la conmutación magnética controlada por patrones de apilamiento de dimeros de bis
Zhaoping Ni1, Xiaoming Ren, Jing Ma
1Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry, and Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, Nanjing University, Nanjing 210093, P. R. China.
Journal of the American Chemical Society
|October 13, 2005
Resumen
La teoría funcional de la densidad revela que el apilamiento molecular y la unión intermolecular en los complejos de maleonitrileditiolato (mnt) impulsan la conmutación magnética. El deslizamiento de modulación en estos complejos [Ni(mnt)(2)](-) permite dispositivos de conmutación magnética molecular.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química computacional es la química computacional.
- Física del estado sólido Física del estado sólido
Sus antecedentes:
- Los complejos de maleonitrileditiolato (mnt) exhiben interesantes propiedades magnéticas.
- La comprensión de las correlaciones magnetostructural es clave para diseñar materiales magnéticos moleculares.
Objetivo del estudio:
- Para investigar las correlaciones magnetostructural en dímeros de aniones de [RBzPyR'][Ni(mnt)(2) ] utilizando la teoría funcional de la densidad.
- Para aclarar la naturaleza de la débil unión química intermolecular y su papel en la conmutación magnética.
Principales métodos:
- Cálculos de la teoría funcional de la densidad (DFT).
- Análisis de la órbita de enlace natural (NBO, por sus siglas en inglés).
- Variación sistemática de los parámetros estructurales (distancia entre capas, deslizamiento, rotación).
Principales resultados:
- La deslocalización del espín debido al apilamiento eclipsado y la corta distancia entre capas conduce al diamagnetismo a bajas temperaturas.
- Se observaron débiles interacciones antiferromagnéticas y ferromagnéticas a altas temperaturas.
- Los efectos cooperativos de enlace intermolecular se identifican como la fuerza motriz de las propiedades magnéticas conmutables.
Conclusiones:
- El grado de deslizamiento influye significativamente en las interacciones magnéticas en los complejos [Ni(mnt) ((2)) ] ((-).
- La modulación del deslizamiento a través de perturbaciones externas ofrece una vía para diseñar dispositivos de conmutación magnética molecular.
- Los hallazgos proporcionan información sobre los principios de diseño para nuevos materiales magnéticos.
Más Videos Relacionados
Videos de Conceptos Relacionados
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
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...
01:31Ferromagnetism
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...