Video Experimental Relacionado
Updated: Jul 18, 2026
06:31
Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase
Published on: March 19, 2020
Reducción de la potencia del cobalto de tres coordenadas (I)
Michael J Ingleson1, Maren Pink, Kenneth G Caulton
1Department of Chemistry, Indiana University, Bloomington, 47405-7102, USA.
Journal of the American Chemical Society
|March 30, 2006
Resumen
Los complejos de cobalto con ligandos PNP se unen fácilmente al monóxido de carbono, lo que indica un centro de cobalto fácilmente oxidado. Sin embargo, la oxidación completa al cobalto (III) es un desafío, con la formación de especies intermedias en su lugar.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Coordinación Química de la Coordinación
- Síntesis Inorgánica y Síntesis Inorgánica.
Sus antecedentes:
- La reactividad de los complejos de metales de transición de baja valencia es crucial para la catálisis y la ciencia de los materiales.
- Los complejos de cobalto, particularmente con ligandos de fosfina, son de interés debido a sus diversos estados de oxidación y capacidades de enlace.
- La comprensión de las propiedades electrónicas y las vías de oxidación de los complejos de cobalto informa el diseño de nuevas moléculas funcionales.
Objetivo del estudio:
- Para investigar la química de coordinación y el comportamiento de oxidación de un complejo de cobalto soportado por un ligando PNP voluminoso.
- Para caracterizar los productos formados por la reacción con monóxido de carbono y agentes oxidantes.
- Para explorar los límites de la oxidación del cobalto dentro de este entorno ligando específico.
Principales métodos:
- Síntesis y caracterización del complejo (PNP) Co.
- Espectroscopia infrarroja para estudiar la coordinación del monóxido de carbono.
- Reacciones con yodo (I2) y un compuesto diazo (N2CH(SiMe3)) para analizar la oxidación.
- Cristalografía de rayos X para determinar la estructura de los productos de reacción.
Principales resultados:
- La adición de monóxido de carbono a (PNP) Co produce (PNP) Co ((CO), con un valor nuco de 1885 cm-1, lo que indica una retro-donación significativa y un centro Co ((I) fácilmente oxidado.
- La oxidación de (PNP) Co con I2 no conduce a una especie estable de Co (III); en su lugar, se forman (PNP) CoI y un complejo de Co (III) zwitteriónico, [ItBu2PCH2SiMe2NSiMe2CH2PtBu2]CoI2.
- La reacción con N2CH ((SiMe3) da como resultado un adducto 1:1 cuya estructura cristalina sugiere una oxidación parcial de Co ((I), corta a un estado de Co ((III) completo.
Conclusiones:
- El voluminoso ligando PNP estabiliza un estado Co (I) fácilmente oxidable, lo que facilita la unión de CO.
- La accesibilidad del centro de cobalto a estados de oxidación más altos, como el Co, es estérico y electrónicamente limitada por el ligando PNP y las condiciones de reacción.
- La reactividad observada pone de relieve el control matizado sobre las propiedades redox que se puede lograr con un diseño de ligando a medida en la química organometálica.
Más Videos Relacionados
08:40Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
09:03Barrier Functional Integrity Recording on bEnd.3 Vascular Endothelial Cells via Transendothelial Electrical Resistance Detection
Published on: September 29, 2023
Videos de Conceptos Relacionados
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...
02:57Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
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...
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.