Ahn S, Lisitza N, Warren WS
Department of Chemistry, Princeton University, New Jersey, 08544-1009, USA.
J Magn Reson. 1998 Aug;133(2):266-72. doi: 10.1006/jmre.1998.1461.
Intermolecular zero-quantum coherences (iZQC) induced by the dipolar demagnetizing field can give both P- and N-type cross peaks. This paper shows that the relative intensities of the two types of iZQC peaks follow a simple relation, tan2 (theta/2), from both the quantum (spin density matrix) and classical (modified Bloch equation) calculations. The experimental data and numerical simulations agree well with the prediction. In addition, higher-order iZQCs are experimentally examined for the first time and are explained by the quantum picture in which dipolar couplings convert four-spin operators into observable magnetization. Copyright 1998 Academic Press.
由偶极退磁场诱导的分子间零量子相干（iZQC）可产生P型和N型交叉峰。本文表明，通过量子（自旋密度矩阵）和经典（修正的布洛赫方程）计算，这两种iZQC峰的相对强度遵循一个简单的关系，即tan2(θ/2)。实验数据和数值模拟与该预测结果吻合良好。此外，首次对高阶iZQC进行了实验研究，并用量子图像进行了解释，在该图像中，偶极耦合将四自旋算符转换为可观测的磁化强度。版权所有1998年学术出版社。
