一个超分子化的离子化 (III) 复合体,产生明亮且非常稳定的固态发光电化学电池
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
概括
一种具有pi堆叠的新型 (III) 复合物增强了固态发光电化学电池 (LEC) 的稳定性. 这一突破为延长设备寿命和高亮度的实际应用提供了一条道路.
科学领域:
- 材料科学 材料科学 材料科学
- 化学 化学 化学
- 固态物理 固态物理
背景情况:
- 发光电化学电池 (LEC) 对照明应用具有前景.
- 提高LEC的运行稳定性和亮度对于实际使用至关重要.
- 现有的离子复合体往往缺乏所需的长期稳定性.
研究的目的:
- 为了合成一种新的 (III) 复合物,与分子内互连体pi-stacking.
- 调查该复合体对单元,固态LEC设备稳定性的影响.
- 评估这种方法在实现实际LEC应用方面的潜力.
主要方法:
- 合成了一种新型的 (III) 复合物,其特征是分子内互联联体pi-stacking.
- 使用合成的复合物制造单元,固态发光电化学电池 (LEC) 设备.
- 设备性能的表征,包括稳定性 (寿命) 和亮度测量.
主要成果:
- 由于pi堆叠,形成了一个稳定的超分子化 (III) 复合体.
- 包含这种复合物的LEC表现出了非凡的稳定性,估计寿命为600小时.
- 这些设备实现了高平均亮度值230 cd m-2.
结论:
- 在 (III) 复合体中,分子内联体pi堆叠可以显著提高LEC的稳定性.
- 开发的综合体提供了一条通往高度稳定和高效的固态LEC的可行途径.
- 这项研究为LEC技术的实际应用铺平了道路.
相关概念视频
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.