外部电场对ESDPT过程和1,8-二二二甲基的光物理性质的影响
Xingzhu Tang1, Yajie Zhang1, Chaofan Sun1
1College of Science, Northeast Forestry University, Harbin 150040, Heilongjiang, China. cfsun@nefu.edu.cn.
Physical chemistry chemical physics : PCCP
|March 19, 2024
概括
外部电场 (EEF) 影响了1,8-二基-2-甲 (DHNA) 中激发状态的双重分子内质子转移 (ESDPT). 这些场改变了质子转移动态和光物理性质,可以控制发光.
科学领域:
- 计算化学计算化学
- 光物理学的光学物理学
- 量子化学 是一个量子化学.
背景情况:
- 分子内质子转移 (IPT) 对分子功能至关重要.
- 了解激发状态动态是设计光响应材料的关键.
- 1,8-二基-2-甲 (DHNA) 具有有趣的光物理特性.
研究的目的:
- 研究外部电场 (EEF) 对DHNA激发状态双重分子内质子转移 (ESDPT) 的影响.
- 分析EEF如何改变光物理性质和质子转移途径.
- 探索EEFs在通过质子转移控制发光的潜力.
主要方法:
- 使用密度函数理论 (DFT) 和时间依赖密度函数理论 (TD-DFT).
- 计算包括对分子内键 (IHB) 参数,红外振动光谱和潜在能量表面 (PESs) 的分析.
- 在外部电场的各种强度和方向下进行了模拟.
主要成果:
- 电场效应显著改变IBH强度,证据是键长度,角度和红外光谱的变化.
- 在DHNA中,ESDPT过程被证实是阶段性的.
- 增加正的EEF降低了ESDPT的能源障碍,而负的EEF增加了它.
- 吸收和光光谱根据EEF呈现红色或蓝色转移,随着EEF的增加,Keto2形式的蓝色从602nm转移到513nm.
结论:
- 在DHNA中,EEF有效调节ESDPT过程.
- 该研究提供了一种通过外部电场控制质子转移和发光的机制.
- 这些发现为设计和调节光诱导质子转移系统提供了宝贵的参考.
相关概念视频
π Electron Effects on Chemical Shift: Overview
1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
1.2K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.2K
Variables Affecting Phosphorescence and Fluorescence
499
Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...
499
Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
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
1.8K
Induced Electric Dipoles
4.2K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.2K
Nuclear Overhauser Enhancement (NOE)
676
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the Nuclear Overhauser Enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring...
676


