Video Experimental Relacionado
Updated: May 30, 2026
07:20
Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
Complejos de platino ciclometalizado (II) que contienen diarileteno: fotocromismo sintonizable a través de la
Jacky Chi-Hung Chan1, Wai Han Lam, Hok-Lai Wong
1Institute of Molecular Functional Materials, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
Journal of the American Chemical Society
|July 26, 2011
Resumen
Los nuevos complejos de platino (II) con ligandos fotocrómicos de dietienileteno exhiben cambios de color reversibles tras la exposición a la luz. Sus propiedades son sintonizables por diseño de ligandos y ligandos auxiliares, ofreciendo potencial para materiales fotorresponsivos avanzados.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Ciencia de los materiales Ciencia de los materiales.
- La fotoquímica es la fotoquímica.
Sus antecedentes:
- Los complejos de platino ciclometalizado ((II) se investigan por sus propiedades fotofísicas únicas.
- Los materiales fotocrómicos que sufren cambios de color reversibles tras la irradiación de luz son de gran interés.
- Las unidades de DTE son conocidas por su eficiente comportamiento fotocrómico.
Objetivo del estudio:
- Para sintetizar y caracterizar una nueva serie de complejos de platino ciclometalizado (II) que incorporan ligandos fotocrómicos de dietieniletheno.
- Investigar las propiedades electroquímicas, fotofísicas y fotocrómicas de estos nuevos complejos.
- Para explorar la influencia de la estructura del ligando y los ligandos auxiliares en las propiedades observadas.
Principales métodos:
- Síntesis de complejos de platino ciclometalizado (II) con diferentes ligandos C () N y O () O.
- Cristalografía de rayos X para la determinación estructural.
- Análisis electroquímico (voltametría cíclica) para estudiar las propiedades redox y los niveles de LUMO.
- Las mediciones fotofísicas (absorción, emisión) para evaluar la fotoquímica.
- Estudios de comportamiento fotocromático bajo fotoexcitación y cinética de blanqueamiento térmico.
- Cálculos de la Teoría Funcional de Densidad (DFT, por sus siglas en inglés) para obtener información teórica.
Principales resultados:
- Síntesis y caracterización exitosas de nuevos complejos de platino (II) [Pt (C) (N) (O) (O) ].
- Los estudios electroquímicos mostraron que el orbital molecular desocupado más bajo (LUMO) es sensible a los ligandos auxiliares O() O.
- Los complejos exhibieron fotocromismo reversible con cambios de color significativos tras la fotoexcitación.
- El comportamiento fotocrómico fue influenciado por los sustituyentes en el anillo pirídico, la π-conjugación del ligando C() N y los ligandos auxiliares.
- Se determinaron la cinética de blanqueamiento térmico y la barrera de activación para la cicloinversión térmica de un complejo representativo.
- Los cálculos de DFT proporcionaron información sobre las propiedades observadas.
Conclusiones:
- Los nuevos complejos de platino ciclometalizado (II) demuestran un comportamiento fotocrómico sintonizable.
- El diseño de los ligandos, incluida la unidad DTE y los ligandos auxiliares, juega un papel crucial en el control de las propiedades fotorresponsivas.
- Estos hallazgos contribuyen al desarrollo de materiales fotocrómicos avanzados basados en complejos de platino.
Más Videos Relacionados
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Videos de Conceptos Relacionados
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.
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...
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
02:52Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
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