在9,10-Bis(phenylethynyl) 炭烯中,三元体的形成通过电荷重组而不是单点裂变而发生
Rasmus Ringström1, Zachary W Schroeder2, Letizia Mencaroni3
1Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
The journal of physical chemistry letters
|August 29, 2023
概括
在9,10-bis(phenylethynyl) 炭二元和三元中,三元体的形成是由极性溶剂中的电荷重组而不是单片裂变驱动的. 在高度下, Excimer 形成主导着单体衰变.
科学领域:
- 摄影化学的使用.
- 材料科学 材料科学 材料科学
- 频谱学是一种光谱学.
背景情况:
- 了解激发状态动态对于设计先进材料至关重要.
- 9,10-bis(phenylethynyl) anthracene (BPEA) 衍生物正在研究它们的光物理性质.
- 与单体相比,寡合体结构可以表现出独特的行为.
研究的目的:
- 调查BPEA单体,二元和三元体的依赖溶剂的兴奋状态动态.
- 阐明BPEA寡合体中三重激发状态形成的机制.
- 探索度和聚合对BPEA光物理学的影响.
主要方法:
- 暂时吸收光谱学被用来研究兴奋状态动态.
- 总内部反射辐射测量用于单体分析.
- 通过各种溶剂极性和度进行了实验.
主要成果:
- 在极性溶剂中,BPEA二聚体和三聚体的三重兴奋状态形成是电荷分离后的电荷重组的结果,而不是单点裂变.
- 高度的BPEA单体的主要衰变途径是排泄物形成.
- 在缩的BPEA三元体溶液中,三元体形成发生在没有先前的电荷分离的情况下,归因于聚合物形成.
结论:
- 溶剂和度显著影响BPEA寡合物的光物理路径.
- 在BPEA三元体中聚合物形成可能会促进三元体的形成,可能模仿晶体的行为.
- 这些发现为控制光电子应用的兴奋状态动态提供了洞察力.
相关概念视频
01:18Aromatic Hydrocarbon Cations: Structural Overview
2.8K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
2.8K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.4K
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.
2.4K
03:35Hybridization of Atomic Orbitals II
32.4K
sp3d and sp3d 2 Hybridization
32.4K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.9K
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
1.9K
01:17Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
2.6K
Ideally, an unpaired electron shows a single peak in the EPR spectrum due to the transition between the two spin energy states. However, coupling interactions can occur between the spins of the unpaired electron and any neighboring spin-active nuclei. This hyperfine coupling results in hyperfine splitting, where the EPR signal is split into multiplets. The signals split into 2nI + 1 peaks, where n is the number of equivalent nuclei and I is the nuclear spin. These splitting patterns provide...
2.6K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.1K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.1K