液压压力对氧化物基的g张量和高精度合常数的影响,其特点是Ab Initio计算
Ana Gurgenidze1, Anna I Krylov1, Susumu Takahashi1,2
1Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States.
The journal of physical chemistry letters
|June 5, 2025
概括
高水静压线性地改变了电子磁共振 (EPR) 光谱分析的磁自旋参数. 这些压力诱导的g和A张量变化可以报告生物系统中的局部压力.
科学领域:
- 计算化学是一种计算化学.
- 生物物理学的生物物理.
- 频谱学是一种光谱学.
背景情况:
- 电子偏磁共振 (EPR) 光谱与位点定向旋转标记 (SDSL) 对于研究生物分子至关重要.
- 精确的磁自旋参数 (g因子,超细常数) 对于EPR分析至关重要.
- 在高压下实验性地确定这些参数是具有挑战性的.
研究的目的:
- 通过计算来描述水静压对磁自旋参数的影响.
- 为了研究氧化基的g和A张量中压力诱导的变化.
- 评估这些参数作为局部压力传感器的实用性.
主要方法:
- 使用了量子化学计算.
- 计算涵盖了0-15 GPa的水静压范围.
- 在9和230 GHz生成模拟的EPR频谱.
主要成果:
- 液压压力诱导g张量和高精度合 (A) 张量的线性变化.
- 计算的g和A张量表现出对施加压力的线性依赖.
- 与230 GHz相比,模拟的EPR频谱在9 GHz显示出更明显的变化.
结论:
- 计算方法可以在高水静压下确定磁自旋参数.
- 观察到的线性关系表明g和A张量器可以充当压力报告器.
- 这种方法有助于理解极端压力条件下的生物系统.
相关概念视频
Spin–Spin Coupling: One-Bond Coupling
1.1K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.1K
The Equilibrium Constant
49.4K
Consider the oxidation of sulfur dioxide:
49.4K
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
2.7K
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...
2.7K
Spin–Spin Coupling Constant: Overview
1.0K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.0K
Calculating Equilibrium Concentrations
48.7K
Being able to calculate equilibrium concentrations is essential to many areas of science and technology—for example, in the formulation and dosing of pharmaceutical products. After a drug is ingested or injected, it is typically involved in several chemical equilibria that affect its ultimate concentration in the body system of interest. Knowledge of the quantitative aspects of these equilibria is required to compute a dosage amount that will solicit the desired therapeutic effect.
A more...
A more...
48.7K
Free Energy Changes for Nonstandard States
11.7K
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
11.7K


