...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical chemistry chemical physics: PCCP >t(1)-Noise eliminated dipolar heteronuclear multiple-quantum coherence solid-state NMR spectroscopy
【24h】

t(1)-Noise eliminated dipolar heteronuclear multiple-quantum coherence solid-state NMR spectroscopy

机译：T（1） - 不含Dipolar异核多量子相干固态NMR光谱

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Heteronuclear correlation (HETCOR) spectroscopy is one of the key tools in the arsenal of the solid-state NMR spectroscopist to probe chemical and spatial proximities between two different nuclei and enhance spectral resolution. Dipolar heteronuclear multiple-quantum coherence (D-HMQC) is a powerful technique that can be potentially utilized to obtain(1)H detected 2D HETCOR solid-state NMR spectra of any NMR active nucleus. A long-standing problem in(1)H detected D-HMQC solid-state NMR experiments is the presence oft(1)-noise which reduces sensitivity and impedes spectral interpretation. In this contribution, we describe novel pulse sequences, termedt(1)-noise eliminated (TONE) D-HMQC, that minimizet(1)-noise and can provide higher sensitivity and resolution than conventional D-HMQC. Monte-Carlo and numerical simulations confirm thatt(1)-noise in conventional D-HMQC primarily occurs because random MAS frequency fluctuations cause variations in the NMR signal amplitude from scan to scan, leading to imperfect cancellation of uncorrelated signals by phase cycling. The TONE D-HMQC sequence uses(1)H pi-pulses to refocus the evolution of(1)H CSA across each SR421 recoupling block, improving the stability of the pulse sequence to random MAS frequency fluctuations. The(1)H refocusing pulses also restore the orthogonality of in-phase and anti-phase magnetization for all crystallite orientations at the end of each recoupling block, enabling the use of 90 degrees flip-back or LG spin-lock trim pulses to reduce the intensity of uncorrelated signals. We demonstrate the application of these methods to acquire(1)H detected 2D(1)H{Cl-35} and(1)H{C-13} HETCOR spectra of histidine center dot HCl center dot H2O with reducedt(1)-noise. To show generality, we also apply these methods to obtain 2D(1)H{O-17} spectra of 20%-O-17 fmoc-alanine and for the first time at natural abundance, 2D(1)H{Mg-25} HETCOR spectra of magnesium hydroxide. The TONE D-HMQC sequences are also used to probe(1)H-Mg-25 and(1)H-Al-27 proximities in Mg-Al layered double hydroxides and confirm the even mixing of Mg and Al in these materials.
机译：异核相关性（Hetcor）光谱是固态NMR光谱分子中的突出部中的关键工具之一，以探测两种不同核之间的化学和空间近距离并增强光谱分辨率。偶极异核多量子相干（D-HMQC）是一种强大的技术，可以有可能用于获得任何NMR活性核的检测到的2D Hetcor固态NMR光谱。在（1）H检测到的D-HMQC固态NMR实验中的长期问题是（1） - 不降低灵敏度并阻碍光谱解释的存在。在这一贡献中，我们描述了新型脉冲序列，DERGEDT（1） - 不消除（音调）D-HMQC，该最小值（1） - 不良，并且可以提供比传统D-HMQC更高的灵敏度和分辨率。 Monte-Carlo和数值模拟确认在传统的D-HMQC中，主要发生在传统的D-HMQC中，因为随机MAS频率波动导致从扫描到扫描的NMR信号幅度的变化，导致通过相循环不相关信号消除不相关的信号。音调D-HMQC序列使用（1）H Pi-脉冲来重新聚焦（1）H CSA的演变，每个SR421重跳块，提高脉冲序列到随机MAS频率波动的稳定性。 （1）H重击脉冲还恢复了每个循环块端的所有微晶取向的同相和抗相磁化的正交性，使得使用90度折叠或LG旋转锁定脉冲以减少不相关信​​号的强度。我们证明了这些方法的应用获取（1）H检测到的2D（1）H {Cl-35}和（1）H {C-13}组合氨酸中心点HCl中心点H2O的Hetcor Spectra与Specttt（1） - 噪音。为了表现出一般性，我们还应用这些方法，以获得20％-O-17 Fmoc-丙氨酸的2D（1）小时{O-17}光谱，并在天然丰度，2D（1）H {MG-25氢氧化镁的Hetcor光谱。音调D-HMQC序列还用于探测（1）H-Mg-25和（1）H-Al-27邻近Mg-Al层叠双氢氧化物，并确认在这些材料中的Mg和Al的均匀混合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号