Ahn S, Warren W S, Lee S
Department of Chemistry, Princeton University, Princeton, New Jersey 08544-1009, USA.
J Magn Reson. 1997 Oct;128(2):114-29. doi: 10.1006/jmre.1997.1226.
A recently introduced density matrix picture for dipolar effects in solution NMR (1996, J. Chem. Phys. 105, 874) gave complete solutions for intermolecular multiple-quantum coherences for single-component samples without scalar couplings. This paper, for the first time, shows that this quantum picture can lead to explicit signal expressions for multicomponent samples of molecules with internal scalar couplings (here assumed to generate a first-order spectrum) and long-range dipolar couplings. Experimental observation of a triplet in the indirectly detected dimension for a heteronuclear CRAZED sequence (13CHCl3 sample, ZQ or 2Q coherences) gives clear evidence that the coupling is due to the intermolecular dipolar coupling. We also make comparisons with classical pictures which introduce the dipolar demagnetization field in multicomponent spin systems.
最近引入的用于溶液核磁共振中偶极效应的密度矩阵图景（1996年，《化学物理杂志》105卷，874页）给出了无标量耦合的单组分样品分子间多量子相干的完整解。本文首次表明，这种量子图景能够得出具有内部标量耦合（这里假定产生一阶谱）和长程偶极耦合的多组分分子样品的显式信号表达式。对于异核CRAZED序列（13CHCl3样品，ZQ或2Q相干）在间接检测维度上三重峰的实验观测，清楚地证明了这种耦合是由分子间偶极耦合引起的。我们还与在多组分自旋系统中引入偶极退磁场的经典图景进行了比较。
