Video Experimental Relacionado
Updated: Feb 22, 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
9.9K
El análisis estructural electrónico de los complejos cobre-tempó/abno proporciona pruebas del carácter
Richard C Walroth1, Kelsey C Miles2, James T Lukens1
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853, United States.
Journal of the American Chemical Society
|September 19, 2017
Resumen
La coordinación del cobre altera significativamente los ligandos aminoxilo, revelando conocimientos clave sobre los mecanismos de oxidación del alcohol aeróbico y la cooperatividad del co-catalizador.
Área de la Ciencia:
- Química inorgánica
- Catálisis
- Espectroscopia
Sus antecedentes:
- Las especies de cobre/aminoxilo son intermediarios cruciales en la oxidación del alcohol aeróbico.
- Comprender su estructura electrónica es vital para elucidar los mecanismos catalíticos.
Objetivo del estudio:
- Investigar la estructura electrónica de las especies de cobre/aminoxilo.
- Para determinar la naturaleza de las interacciones cobre-aminoxilo y cobre-haluro.
- Proporcionar información sobre la cooperatividad de los cocatalizadores de cobre-aminoxilo.
Principales métodos:
- Se utilizó la espectroscopia de absorción de rayos X Cu K-edge, Cu L2,3-edge y Cl K-edge en cuatro complejos de haluros de Cu/aminoxilo caracterizados cristalográficamente.
- Utilizó cálculos de la teoría funcional de la densidad (DFT) para apoyar el análisis de datos espectroscópicos.
- Metodología computacional extendida a un supuesto intermediario catalítico.
Principales resultados:
- Coeficientes de mezcla determinados entre los orbitales de cobre, aminoxilo y haluro.
- Se estableció que la coordinación del cobre imparte un carácter significativo de oxoamonio al ligando aminoxilo.
- El análisis computacional de un intermediario catalítico produjo hallazgos similares de la estructura electrónica.
Conclusiones:
- Se ha aclarado la estructura electrónica de las especies de cobre/aminoxilo.
- La coordinación del cobre juega un papel crítico en la activación del ligando aminoxilo para la oxidación del alcohol.
- Estos hallazgos avanzan en la comprensión de los mecanismos de oxidación del alcohol aeróbico y la función de co-catalizador.
Videos de Conceptos Relacionados
02:42Valence Bond Theory
11.4K
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...
11.4K
01:07Ladder Diagrams: Complexation Equilibria
654
Ladder diagrams are useful for evaluating equilibria involving metal-ligand complexes. The vertical scale of the ladder diagram represents the concentration of unreacted or free ligand, pL. The horizontal lines on the scale depict the log of stepwise formation constants for metal-ligand complexes and indicate the dominant species in all the regions.
The formation constant, K1, for the formation of Cd(NH3)2+ complex from cadmium and ammonia is 3.55 × 102. Log K1 (i.e. pNH3) is 2.55, and...
The formation constant, K1, for the formation of Cd(NH3)2+ complex from cadmium and ammonia is 3.55 × 102. Log K1 (i.e. pNH3) is 2.55, and...
654
03:02Colors and Magnetism
14.2K
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...
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...
14.2K
02:58Crystal Field Theory - Octahedral Complexes
31.1K
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...
31.1K
02:57Coordination Number and Geometry
19.2K
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.
19.2K
02:51Metal-Ligand Bonds
24.6K
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...
24.6K