International Tomography Center, Siberian Branch of the Russian Academy of Science, Novosibirsk 630090, Russia.
School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
J Chem Phys. 2019 Feb 14;150(6):064201. doi: 10.1063/1.5079436.
A method is implemented to perform "fast" adiabatic variation of the spin Hamiltonian by imposing the constant adiabaticity condition. The method is applied to improve the performance of singlet-state Nuclear Magnetic Resonance (NMR) experiments, specifically, for efficient generation and readout of the singlet spin order in coupled spin pairs by applying adiabatically ramped RF-fields. Test experiments have been performed on a specially designed molecule having two strongly coupled C spins and on selectively isotopically labelled glycerol having two pairs of coupled protons. Optimized RF-ramps show improved performance in comparison, for example, to linear ramps. We expect that the methods described here are useful not only for singlet-state NMR experiments but also for other experiments in magnetic resonance, which utilize adiabatic variation of the spin Hamiltonian.
一种通过施加恒定绝热条件来执行自旋哈密顿量“快速”绝热变化的方法得到了实现。该方法应用于提高单态核磁共振（NMR）实验的性能，特别是通过施加绝热调频射频场来有效地产生和读出耦合自旋对中的单态自旋顺序。已经在具有两个强耦合 C 自旋的特殊设计分子上和在具有两个耦合质子对的选择性同位素标记的甘油上进行了测试实验。与线性斜坡相比，优化的 RF 斜坡显示出了更好的性能。我们期望这里描述的方法不仅对单态 NMR 实验有用，而且对利用自旋哈密顿量绝热变化的其他磁共振实验也有用。
