Experimental access to HSQC spectra decoupled in all frequency dimensions
Experimental access to HSQC spectra decoupled in all frequency dimensions
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DOI：
10.1016/j.jmr.2009.04.016
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发表时间：
2009-08-01
影响因子：
2.2
通讯作者：
Bermel, Wolfgang
中科院分区：
文献类型：
--
作者：
Sakhaii, Peyman;Haase, Burkhard;Bermel, Wolfgang
本文提出了一种新的算符“将核自旋多重数E降为单重数T”，用以获得一维和二维宽频带质子去偶谱。基本上，通过应用双线性旋转脉冲和延迟来实现同态解耦。使用[BIRD]（cx）脉冲构建块来选择性地反转远程连接到C-13同位素的所有质子磁化，这相当于直接连接到C-13的质子与自旋系统中的所有其他质子的标量J去耦。结合适当的数据处理技术，得到纯位移质子谱。为此，利用观测维中的恒定时间采集的概念。这两个想法合并在一起，产生基于上级HSQC的伪3D脉冲序列。所得的HSQC光谱显示交叉峰与崩溃的多重态结构和单重态响应的质子化学位移频率。一个明确的分配信号从拥挤的光谱变得容易得多。最后，最近推出的SHARC技术被用来提高标量J解耦方法的能力。实现了总测量时间的显著减少。通过减少C-13化学位移演化增量的数量和在C-13间接域中使用叠加的窄光谱带宽来节省时间。(C)2009 Elsevier Inc. All rights reserved.
A new operator called RESET "Reducing nuClEar Spin multiplicitiEs to singuleTs" is presented to acquire broadband proton decoupled proton spectra in one and two dimensions. Basically, the homonuclear decoupling is achieved through the application of bilinear rotation pulses and delays. A [BIRD](cx) pulse building block is used to selectively invert all proton magnetization remotely attached to C-13 isotopes, which is equivalent to a scalar J decoupling of the protons directly attached to C-13 from all other protons in the spin system. In conjunction with an appropriate data processing technique pure shift proton spectra are obtained. For this purpose, the concept of constant time acquisition in the observe dimension is exploited. Both ideas were merged together producing superior HSQC based pseudo 3D pulse sequences. The resulting HSQC spectra show Cross peaks with collapsed multiplet structures and singlet responses for the proton chemical shift frequencies. An unambiguous assignment of signals from overcrowded spectra becomes much easier. Finally, the recently introduced SHARC technique is exploited to enhance the capability of the scalar J decoupling method. A significant reduction of the total measurement time is achieved. The time is saved by reducing the number of C-13 chemical shift evolution increments and working with superimposed narrow spectral bandwidths in the C-13 indirect domain. (C) 2009 Elsevier Inc. All rights reserved.