Video Experimental Relacionado
Updated: Jun 25, 2026
14:44
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Un sistema molecular único que bloquea la transferencia de electrones por inversión de anillo de un ligando de
Kuniharu Nomoto1, Shoko Kume, Hiroshi Nishihara
1Department of Chemistry, Graduate school of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Journal of the American Chemical Society
|March 4, 2009
Resumen
Los investigadores desarrollaron un nuevo sistema de puertas de transferencia de electrones utilizando un complejo de cobre. Este sistema está controlado por el movimiento de rotación de un ligando de piridilpirimidina, lo que permite la conmutación de la transferencia de electrones en función de la temperatura.
Área de la Ciencia:
- Coordinación Química de la Coordinación
- Química supramolecular de las moléculas.
- La electroquímica es electroquímica.
Sus antecedentes:
- Los sistemas de transferencia de electrones son cruciales para la electrónica molecular.
- Controlar dinámicamente la transferencia de electrones es un desafío clave en el campo.
- Los rotores moleculares ofrecen potencial para mecanismos de cerradura receptivos.
Objetivo del estudio:
- Para construir un sistema de transferencia de electrones regulado por la rotación molecular.
- Para investigar la relación entre la dinámica del ligando y el potencial redox.
- Para lograr el encendido/apagado controlado por temperatura de la transferencia de electrones.
Principales métodos:
- Síntesis de un complejo de cobre con un ligando de piridilpirimidina.
- Investigación dinámica del proceso utilizando espectroscopia de RMN en estado de solución.
- Mediciones electroquímicas para determinar los desplazamientos del potencial redox.
Principales resultados:
- Se sintetizó con éxito un complejo de cobre (1.BF(4) con un ligando rotativamente dinámico.
- El ligando de piridilpirimidina exhibió interconversión isomérica con una barrera de 73 kJ mol ((-1) a 293 K.
- Los cambios inducidos por la temperatura en la conformación del ligando cambiaron el potencial redox del centro de cobre en -0.14 V, cerrando la transferencia de electrones.
Conclusiones:
- El estudio demuestra una puerta de transferencia de electrones funcional controlada por rotación molecular.
- La temperatura sirve como un estímulo externo eficaz para modular el comportamiento de las puertas.
- Este trabajo proporciona una base para el diseño de dispositivos electrónicos moleculares receptivos.
![[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
Videos de Conceptos Relacionados
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
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...
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.