在有机晶体中沿质子转移路径映射的位置,使用计算式X射线光谱
Guoyan Ge1, Jun-Rong Zhang1, Sheng-Yu Wang1
1MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, School of Physics, Nanjing University of Science and Technology, 210094 Nanjing, China.
The journal of physical chemistry letters
|May 31, 2024
概括
晶体中的质子转移是使用N 1sX射线光谱学 (XPS/XAS) 绘制的. 这种方法精确地跟踪质子运动,改进了晶体结构分析和理解键动态.
科学领域:
- 物理化学 物理化学
- 频谱学是一种光谱学.
- 晶体学 晶体学是指结晶学.
背景情况:
- 凝结相中的质子转移 (PT) 动态是化学过程的基础.
- 精确确定晶体结构中的质子位置是具有挑战性的.
- 射线光电子/吸收光谱 (XPS/XAS) 提供了探测PT的潜力.
研究的目的:
- 开发和验证2D N 1s XPS/XAS光谱图,用于跟踪有机捐赠-接受盐晶中的质子运动.
- 为了证明N 1s短暂XPS/XAS对位和PT动态的敏感性.
- 将实验数据与理论计算进行比较,以完善对PT机制的理解.
主要方法:
- 一个有机捐赠-接受盐晶的2D N 1s XPS/XAS图的计算.
- 系统地改变N-H距离以模拟质子运动.
- 计算的光谱与实验XPS和XAS数据的比较.
主要成果:
- 通过键成功地绘制了O-H···NO−····· H+-N质子转移过程的光谱映射.
- 证明了N 1s过渡XPS/XAS对位和PT的高度敏感性.
- 通过将O-H长度调整为0.2 Å,在理论和实验之间取得了很好的一致性.
结论:
- N1s过渡XPS/XAS是研究复杂晶体中相关的质子转移动态的强大工具.
- 周期性几何优化对精制质子位置提出了挑战;作为更有效的替代方案,提出了一个缩放的快照协议.
- 这项工作为解释X射线光谱和推进对质子转移的实验研究提供了关键的见解.
相关概念视频
Proton (¹H) NMR: Chemical Shift
1.6K
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei...
Absorption signals of all the protium nuclei...
1.6K
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.0K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.0K
¹H NMR: Complex Splitting
1.3K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.3K
2D NMR: Overview of Heteronuclear Correlation Techniques
171
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
171
X-ray Crystallography
23.9K
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
23.9K
¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons
2.3K
Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...
2.3K


