31P MAS重新聚焦不够的自旋回声 (REINE) 核磁共振光谱:揭示了无序固体中的J合和化学转移二维相关性
Paul Guerry1, Mark E Smith, Steven P Brown
1Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
Journal of the American Chemical Society
|August 4, 2009
概括
这项研究揭示了J合和酸玻璃中的化学转移之间的相关性,使用了一种新的NMR技术. 这些发现澄清了酸盐网络中的结构关系,表明主要是四个单元链.
科学领域:
- 固态核磁共振 (NMR) 光谱学 固态核磁共振 (NMR) 光谱学
- 材料科学 材料科学 材料科学
- 无机化学 无机化学 有机化学
背景情况:
- 了解酸盐玻璃的结构对于其应用至关重要.
- 之前的NMR方法在将J合与化学变化相关联方面存在局限性.
- 再聚焦不够的旋转回声 (REINE) 脉冲序列提供了增强的分辨率.
研究的目的:
- 在酸玻璃中研究J合的二维 (2D) 变化.
- 通过使用REINE序列,揭示J合和 (31) P化学转移之间的更清晰的相关性.
- 为了确定酸玻璃中占主导地位的结构单元.
主要方法:
- 使用了REfocused INADEQUATE旋回回声 (REINE) 脉冲序列用于 (31) P固态MAS NMR.
- 执行了对2D相关性峰值的自旋回声调制的像素对像素的安装.
- 分析的J合 ((2)J((P(1),P(1)), (2)J(P(1),P(2)), (2)J(P(2),P(2))) 和 (31)P的化学变化.
主要成果:
- 获得了明显的2D (31) P REINE峰值,揭示了J合和化学变化之间的相关性.
- 尽管在邻近的 (31) P 化学转移中没有明显的相关性,但观察到这些相关性.
- 发现的J合范围: (2) J(P(1),P(1)) = 13.4-14.8赫兹, (2) J(P(1),P(2)) = 15.0-18.2赫兹, (2) J(P(2),P(2)) = 5.9-9.1赫兹.
- 最适合表示玻璃主要由四个单位的酸盐链组成.
结论:
- REINE序列有效地阐明了酸盐玻璃中的J合-化学转移相关性.
- 这些相关性为酸盐四面体的局部结构提供了洞察力.
- 该研究表明,在0.575CdO-0.425P(2) O(5) 玻璃结构中,四个单元链占主导地位.
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