Matveev Vladimir V, Markelov Denis A, Ievlev Alexandr V, Brui Ekaterina A, Tyutyukin Konstantin V, Lähderanta Erkki
Physical Faculty, Saint Petersburg State University, 7/9 Universitetskaya nab, Saint Petersburg, 199034, Russia.
Laboratory of Physics, Lappeenranta University of Technology, Box 20, 53851, Lappeenranta, Finland.
Magn Reson Chem. 2018 Feb;56(2):140-143. doi: 10.1002/mrc.4681. Epub 2017 Dec 3.
Temperature dependences are compared for H and C NMR 1/T curves relaxation rates in three imidazolium-based ionic liquids (ILs), namely, in [bmim]PF , [bmim]BF , and [emim]CH COO. C curves show alike behavior for all three ILs and follow a well-known Bloembergen-Pound-Purcell (BPP) equation. On the contrary, an essential part of H curves differ strongly from corresponding C ones and also have different shapes for different ILs. For the first time, we have detected the specific, two-maximum shape of H relaxation curve for hydrogen atom of C(2)H group of the [emim]CH COO. Assuming that this maximum reflects the correlated rotation of several adjoining ion pairs, we have tried to destroy this rotation by addition of glycerol to the [emim]CH COO. The second, high-temperature maximum has disappeared in the [emim]CH COO-glycerol mixture, and this fact confirms our assumption. Copyright © 2017 John Wiley & Sons, Ltd.
比较了三种咪唑基离子液体（ILs），即[bmim]PF、[bmim]BF和[emim]CH₃COO中¹H和¹³C NMR 1/T曲线弛豫率的温度依赖性。¹³C曲线显示这三种离子液体具有相似的行为，并遵循著名的布洛姆伯根-庞德-珀塞尔（BPP）方程。相反，¹H曲线的重要部分与相应的¹³C曲线有很大差异，并且不同离子液体的¹H曲线形状也不同。我们首次检测到[emim]CH₃COO中C(2)H基团氢原子的¹H弛豫曲线具有特定的双最大值形状。假设这个最大值反映了几个相邻离子对的相关旋转，我们试图通过向[emim]CH₃COO中添加甘油来破坏这种旋转。在[emim]CH₃COO-甘油混合物中，第二个高温最大值消失了，这一事实证实了我们的假设。版权所有© 2017约翰威立父子有限公司。
