Sheberstov Kirill F, Vieth Hans-Martin, Zimmermann Herbert, Ivanov Konstantin L, Kiryutin Alexey S, Yurkovskaya Alexandra V
1International Tomography Center SB RAS, Novosibirsk, 630090 Russia.
State Scientific Research Institute of Chemistry and Technology of Organoelement Compounds, Moscow, 105118 Russia.
Appl Magn Reson. 2018;49(3):293-307. doi: 10.1007/s00723-017-0968-8. Epub 2017 Dec 22.
We provide a detailed evaluation of nuclear magnetic resonance (NMR) parameters of the - and -isomers of azobenzene (AB). For determining the NMR parameters, such as proton-proton and proton-nitrogen -couplings and chemical shifts, we compared NMR spectra of three different isotopomers of AB: the doubly N labeled azobenzene, N,N'-AB, and two partially deuterated AB isotopomers with a single N atom. For the total lineshape analysis of NMR spectra, we used the recently developed ANATOLIA software package. The determined NMR parameters allowed us to optimize experiments for investigating singlet long-lived spin states (LLSs) of N spin pairs and to measure LLS lifetimes in -AB and -AB. Magnetization-to-singlet-to-magnetization conversion has been performed using the SLIC and APSOC techniques, providing a degree of conversion up to 17 and 24% of the initial magnetization, respectively. Our approach is useful for optimizing the performance of experiments with singlet LLSs; such LLSs can be exploited for preserving spin hyperpolarization, for probing slow molecular dynamics, slow chemical processes and also slow transport processes.
我们对偶氮苯（AB）的α-异构体和β-异构体的核磁共振（NMR）参数进行了详细评估。为了确定NMR参数，如质子-质子和质子-氮的耦合以及化学位移，我们比较了AB的三种不同同位素异构体的NMR光谱：双N标记的偶氮苯N,N'-AB，以及两个具有单个N原子的部分氘代AB同位素异构体。对于NMR光谱的全线形分析，我们使用了最近开发的ANATOLIA软件包。所确定的NMR参数使我们能够优化用于研究N自旋对的单重态长寿命自旋态（LLS）的实验，并测量α-AB和β-AB中的LLS寿命。使用SLIC和APSOC技术进行了磁化-单重态-磁化转换，分别提供了高达初始磁化强度17%和24%的转换程度。我们的方法对于优化单重态LLS实验的性能很有用；这种LLS可用于保持自旋超极化，探测缓慢的分子动力学、缓慢的化学过程以及缓慢的传输过程。
