Heteronuclear intermolecular single-quantum coherences in liquid nuclear magnetic resonance

• 来源期刊: 中国物理B（英文版）
• 关键词: nuclear magnetic resonance heteronuclear multiple-quantum coherences distant dipolar field highly-polarized system
• 年，卷（期）: 2008,（3）
• 页码范围: 915-920
• 页数: 6页
• 语种: 英文

摘要

This paper analyses the heteronuclear Cosy Revamped by Asymmetric Z-gradient Echo Detection pulse sequence.General theoretical expressions of the pulse sequence with arbitrary flip angles were derived by using dipolar field treatment and signals originating from heteronuclear intermolecular single-quantum coherences (iSQCs) in highly-polarized two spin-1/2 systems were mainly discussed in order to find the optimal flip angles.The results show that signals from heteronuclear iSQCs decay slower than those from intermolecular double-quantum coherences or intermolecular zero-quantum coherences. Magical angle experiments validate that the signals are from heteronuclear iSQCs and insensitive to the imperfection of radio-frequency flip angles. All experimental observations are in excellent agreement with theoretical predictions. The quantum-mechanical treatment leads to similar predictions to the dipolar field treatment.