Determination of dipole coupling constants using heteronuclear multiple quantum NMR
Determination of dipole coupling constants using heteronuclear multiple quantum NMR
复制标题
使用异核多量子 NMR 测定偶极耦合常数
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
A. Pines
中科院分区：
文献类型：
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作者：
D. Weitekamp;J. Garbow;A. Pines
本文分析了用NMR技术从N个自旋I = 1/2和一个自旋S的系统中提取偶极耦合的问题。使用各种单量子方法可达到的分辨率进行审查。发展了杂原子多量子（HMQ）NMR理论，特别强调了HMQ谱的上级分辨率。介绍了几种新颖的脉冲序列，包括两步法激发HMQ相干性。对部分取向的[1− 13 C]苯的实验证明了必要的HMQ相干性的激发，并说明了相对谱线强度的计算。讨论了多脉冲序列可实现的几种不同有效汉密尔顿量下的高阶HMQ相干谱。本文介绍了一种新的有效哈密顿量--多脉冲标量异质耦合相互作用（SHRIMP），它是通过用同一个多脉冲序列同时辐照两种自旋物质而实现的。本文描述了实验，它允许异质耦合与S-自旋扩展参数在光谱自由的非均匀加宽。
The problem of extracting dipole couplings from a system of N spins I = 1/2 and one spin S by NMR techniques is analyzed. The resolution attainable using a variety of single quantum methods is reviewed. The theory of heteronuclear multiple quantum (HMQ) NMR is developed, with particular emphasis being placed on the superior resolution available in HMQ spectra. Several novel pulse sequences are introduced, including a two-step method for the excitation of HMQ coherence. Experiments on partially oriented [1−13C] benzene demonstrate the excitation of the necessary HMQ coherence and illustrate the calculation of relative line intensities. Spectra of high order HMQ coherence under several different effective Hamiltonians achievable by multiple pulse sequences are discussed. A new effective Hamiltonian, scalar heteronuclear recoupled interactions by multiple pulse (SHRIMP), achieved by the simultaneous irradiation of both spin species with the same multiple pulse sequence, is introduced. Experiments are described which allow heteronuclear couplings to be correlated with an S-spin spreading parameter in spectra free of inhomogeneous broadening.