¹H NMR study on reorientational dynamics of an ionic liquid, 1-butyl-3-methylimidazolium bromide, accompanied with phase transitions

详细信息	查看全文 | 推荐本文 |

• 作者：Mamoru Imanari ; Masamichi Nakakoshi ; Hiroko Seki ; Keiko Nishikawa
• 关键词：Automated flow cytometry ; Bioreactor monitoring ; Mammalian cell culture ; Single-cell heterogeneity ; Process Analytical Technology ; PAT initiative
• 刊名：Chemical Physics Letters
• 出版年：2008
• 期刊代码：7_00092614
• 类别：ph
• 出版时间：27 June 2008
• 卷：459
• 期：1-6
• 页码：89-93
• 文件大小：249 K

摘要

We measured longitudinal and transverse relaxation times (T₁ and T₂) of 1-butyl-3-methylimidazolium bromide ([bmim]Br) from 203 to 393 K, using pulse ¹H NMR. T₁ and T₂ data show the existence of liquid, super-cooled liquid and ‘coagulated state’. The coagulated state appears only in the cooling process at the temperature where [bmim]Br will crystallize in the heating process. The activation energy for rapid reorientational motions of the alkyl groups in the crystalline state was determined to be 13.3 kJ mol⁻¹. By the T₂ measurement, it was confirmed that very slow reorientational molecular motions of the overall [bmim]⁺ begin near the crystallizing point.