核磁共振中分子间多量子相干及其应用
Intermolecular Multiple-Quantum Coherences and Their Applications in NMR
Abstract
源自核自旋远程偶极相互作用的分子间多量子相干(IMQC)以其独特的性质在核磁共振领域引起了广泛的关注.与常规的单量子相干信号相比,IMQC信号具有下列特性:IMQC信号与实验可控的偶极相关距离为半径的空间区域内的自旋粒子数相关;IMQC信号与局域磁场分布或局域磁化率效应相关;IMQC信号具有独特的弛豫和扩散特性.这些性质使IMQC在核磁共振波谱和成像领域得到了广泛的应用.本文简要介绍了IMQC现象的研究历史以及相应的理论解释,对我们小组这10几年来在IMQC领域的研究进行了系统的阐述,包括对IMQC性质的研究及其在不均匀不稳定场中高分辨核磁共振谱和成像方面的应用研究. Intermolecular multiple-quantum coherences(iMQCs) originated from distant dipolar interactions among spins in different molecules have generated tremendous interests due to its unique properties.Compared to the conventional single-quantum coherence(SQC),iMQCs have following features:firstly,iMQC signals are related to the spins within the range of dipolar correlation distance;secondly,iMQC signals are related to the distribution of local field and susceptibility;finally,iMQCs hold special relaxation and molecular diffusion properties.IMQCs have been widely applied in NMR spectroscopy and MRI.In this review,we firstly made a brief introduction on the research history of iMQC phenomena and related theoretical explanations.We then expatiated on our research in iMQC field during the past ten-plus years,from the early research on the iMQC properties to the iMQC applications in NMR spectroscopy and MRI.