中国物理B ›› 2001, Vol. 10 ›› Issue (6): 558-563.doi: 10.1088/1009-1963/10/6/318

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DIRECT MEASUREMENT OF TRANSVERSE RELAXATION TIME OF INTERMOLECULAR MULTIPLE QUANTUM COHERENCES IN NMR

陈志伟1, 陈忠2, 郑绍宽3, 钟健晖4   

  1. (1)Department of Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China; (2)Department of Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China; University of Rochester Medical Center, Rochester, NY 14642, USA; (3)Department of Physics, Xiamen University, Xiamen 361005, China; Department of Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen Univers
  • 收稿日期:2000-11-09 修回日期:2001-02-26 出版日期:2001-06-15 发布日期:2005-06-12
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos.10005006 and 19975038) and by the National Institute of Health(NIH) of United States (Grant No. NS32024).

DIRECT MEASUREMENT OF TRANSVERSE RELAXATION TIME OF INTERMOLECULAR MULTIPLE QUANTUM COHERENCES IN NMR

Zheng Shao-kuan (郑绍宽)ab, Chen Zhong (陈忠)bc, Chen Zhi-wei (陈志伟)b, Zhong Jian-hui (钟健晖)c   

  1. a Department of Physics, Xiamen University, Xiamen 361005, China; b Department of Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China; c  University of Rochester Medical Center, Rochester, NY 14642, USA
  • Received:2000-11-09 Revised:2001-02-26 Online:2001-06-15 Published:2005-06-12
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos.10005006 and 19975038) and by the National Institute of Health(NIH) of United States (Grant No. NS32024).

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摘要： A one-dimensional NMR method is presented for measuring the transverse relaxation time, T2,n, of intermolecular multiple quantum coherences (IMQCs) of coherence order n in highly polarized spin systems. The pulse sequence proposed in this paper effectively suppresses the effects of radiation damping, molecular diffusion, inhomogeneity of magnetic field, and variations of dipolar correlation distance, all of which may affect quantitation of T2,n. This pulse sequence can be used to measure not only IMQC transverse relaxation time T2,n (n>1) quickly and directly, but also the conventional transverse relaxation time. Experimental results demonstrate that the quantitative relationship between T2,n (n≥1) and T2 is T2,n ≈T2/n. These results will be helpful for understanding the fundamental properties and mechanisms of IMQCs.

Abstract: A one-dimensional NMR method is presented for measuring the transverse relaxation time, T2,n, of intermolecular multiple quantum coherences (IMQCs) of coherence order n in highly polarized spin systems. The pulse sequence proposed in this paper effectively suppresses the effects of radiation damping, molecular diffusion, inhomogeneity of magnetic field, and variations of dipolar correlation distance, all of which may affect quantitation of T2,n. This pulse sequence can be used to measure not only IMQC transverse relaxation time T2,n (n>1) quickly and directly, but also the conventional transverse relaxation time. Experimental results demonstrate that the quantitative relationship between T2,n (n≥1) and T2 is T2,n ≈T2/n. These results will be helpful for understanding the fundamental properties and mechanisms of IMQCs.

Key words: nuclear magnetic resonance, intermolecular multiple quantum coherences, transverse relaxation time, pulsed field gradient

中图分类号:  (Nuclear resonance and relaxation)

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