相关实验视频

Updated: Nov 9, 2025

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

Published on: February 23, 2016

通过动态核极化固态核磁共振监测封闭的多孔材料中的结晶过程

Marie Juramy¹, Romain Chèvre¹, Paolo Cerreia Vioglio¹

¹Aix Marseille Univ, CNRS, ICR, 13397 Marseille, France.

Journal of the American Chemical Society

|April 15, 2021

概括

动态核极化 (DNP) 增强的NMR光谱能够在狭窄的空间内详细研究分子结晶. 这种技术揭示了短暂的阶段和转移性多态,如β-甘氨酸,长时间被困在半孔中.

科学领域:

材料科学
固态化学
光谱学

背景情况:

在分子水平上理解结晶机制是很困难的,因为检测短暂的固体相和随着时间的推移监测相变的挑战.
纳米封闭对结晶的影响尚未完全理解,因此需要先进的现场观测技术.

研究的目的:

为了证明动态核极化 (DNP) 增强的核磁共振 (NMR) 光谱在纳米限制下研究结晶过程的实用性.
为了研究半孔材料中的甘氨酸结晶.
在封闭结晶过程中描述短暂和转移稳定的晶体阶段.

主要方法:

使用DNP增强的NMR光谱进行高灵敏度结晶分析.
使用定制的半孔SBA-15材料与嵌入的TEMPO基来创建纳米封闭 (7-8纳米孔).
在这些狭窄的孔隙中研究了甘氨酸的结晶.

主要成果:

成功观察了甘氨酸结晶的早期阶段,包括从溶液过渡到第一个晶体阶段,在中等.
通过DNP-NMR提高灵敏度,可以检测标准固态NMR无法检测到的中间晶体相.
观察到,基因的转移性β多态通常是暂时的,在SBA-15毛孔内被困超过200天.

结论:

用DNP增强的NMR光谱提供了一种强大的方法来检查各种结晶阶段,特别是在有限的条件下.
在半孔材料中纳米封闭可以稳定其他短暂的晶体多态,如糖氨酸的β多态.
这种方法为在封闭环境中结晶的机械研究开辟了新的途径.

更多相关视频

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

相关概念视频

Double Resonance Techniques: Overview

Double Resonance Techniques: Overview

Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...