Video Experimental Relacionado
Updated: Jun 28, 2026
05:51
Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes
Published on: November 15, 2016
Un complejo iónico de iridio (((III) supramolecularmente enjaulado que produce células electroquímicas emisoras de
Stefan Graber1, Kevin Doyle, Markus Neuburger
1Department of Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland.
Journal of the American Chemical Society
|October 22, 2008
Resumen
Un nuevo complejo de iridio (III) con pi-stacking mejora la estabilidad de las células electroquímicas emisoras de luz en estado sólido (LEC). Este avance ofrece un camino hacia aplicaciones prácticas con vidas de dispositivos extendidas y alta luminancia.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química Química es la química.
- Física del estado sólido Física del estado sólido
Sus antecedentes:
- Las células electroquímicas emisoras de luz (LEC) son prometedoras para aplicaciones de iluminación.
- Mejorar la estabilidad operativa y la luminancia de los LEC es crucial para su uso práctico.
- Los complejos iónicos existentes a menudo carecen de la estabilidad a largo plazo requerida.
Objetivo del estudio:
- Para sintetizar un nuevo complejo de iridio (III) con apilamiento de pi interligando intramolecular.
- Investigar el impacto de este complejo en la estabilidad de los dispositivos LEC de estado sólido de un solo componente.
- Evaluar el potencial de este enfoque para lograr aplicaciones prácticas de LEC.
Principales métodos:
- Síntesis de un nuevo complejo de iridio (III) con pi-stacking de interligando intramolecular.
- Fabricación de dispositivos de células electroquímicas emisoras de luz de estado sólido (LEC) de un solo componente que utilizan el complejo sintetizado.
- Caracterización del rendimiento del dispositivo, incluidas las mediciones de estabilidad (vida útil) y luminancia.
Principales resultados:
- Se formó un complejo de iridio ((III) supramolecularmente enjaulado estable debido al apilamiento de pi.
- Los LEC que incorporan este complejo demostraron una estabilidad extraordinaria, con una vida útil estimada de 600 horas.
- Los dispositivos lograron altos valores de luminancia promedio de 230 cd m-2.
Conclusiones:
- El apilamiento intramolecular de pi interligando en complejos de iridio (III) puede mejorar significativamente la estabilidad de LEC.
- El complejo desarrollado ofrece una ruta viable hacia LECs de estado sólido altamente estables y eficientes.
- Esta investigación allana el camino para aplicaciones prácticas de la tecnología LEC.
Videos de Conceptos Relacionados
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
01:43Electron Transport Chain: Complex III and IV
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
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.
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.