Deuteron quadrupole coupling constants and rotational correlation times of N-D and O-D bonds involved in doubly ionic hydrogen bonds in ionic liquids and their mixtures by means of NMR liquid and solid state experiments

通过NMR液态和固态实验研究离子液体及其混合物中双离子氢键涉及的N-D和O-D键的氘核四极耦合常数和旋转相关时间

• 批准号: 401427621
• 负责人: Professor Dr. Ralf Ludwig
• 金额: --
• 依托单位: Lehrstuhl für Allgemeine Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/401427621?language=en
• 关键词: Deuteron; quadrupole; coupling; constants; rotational

We want to determine NMR deuteron quadrupole coupling constants (DQCCs) and rotational correlation times of N-D and O-D molecular vectors involved in doubly ionic hydrogen bonds (DIHBs) of ionic liquids (ILs) and their mixtures. Usually, due to fast proton exchange on the NMR time scale, expensive 15N- or 17O-enhanced proton relaxation time experiments are needed to determine accurate DQCCs for the liquid phase. To avoid the demanding and costly synthesis of isotopically substituted compounds, we recently developed a method for deriving DQCCs from a relation between density functional theory (DFT) calculated N-D DQCCs and N-H proton chemical shifts within clusters of ionic liquids. With simple measurements of the proton chemical shifts, we have access to accurate DQCCs in the liquid phase. This approach is valid regardless of temperature and solvent effects. As proof of concept, we could show that this relation also holds for molecular liquids, such as ammonia or amides. In this project, a similar relation will be calculated for O-D/O-H bonds of cations. Both relations are valid for all N-D or O-D bonds in the investigated liquids either being ionic or molecular. For further judgement of the predicted DQCCs, we will also measure these coupling parameters in the solid phase by means of solid state NMR. Reliable DQCCs are a prerequisite for the determination of rotational correlation times from NMR deuteron quadrupole relaxation rates. Using this approach, the first reliable single particle rotational correlation times can be determined for ionic liquids and their mixtures. They will describe the rotational dynamics for N-D and O-D bonds which are involved in DIHBs in different molecular configurations, such as ion pairs or ionic clusters. The correlation times will be determined as a function of temperature, providing important information about the heterogeneity in protic ionic liquids (PILs). Moreover, the applicability of hydrodynamic models will be tested for the liquid systems including different neutral or ionic aggregates. The first reliable rotational correlation times are also of importance for the force field development of ionic liquids. This has been demonstrated earlier for molecular liquids, such as water and alcohols.

本文测定了离子液体及其混合物中双离子氢键（DIHB）所涉及的N-D和O-D分子矢量的核磁共振氘四极耦合常数（DQCC）和转动相关时间。通常，由于NMR时间尺度上的快速质子交换，需要昂贵的15 N或17 O增强质子弛豫时间实验来确定液相的精确DQCC。为了避免要求和昂贵的合成同位素取代的化合物，我们最近开发了一种方法，用于从密度泛函理论（DFT）计算的N-D DQCC和离子液体簇内的N-H质子化学位移之间的关系推导DQCC。通过对质子化学位移的简单测量，我们可以获得液相中精确的DQCC。这种方法是有效的，无论温度和溶剂的影响。作为概念的证明，我们可以证明这种关系也适用于分子液体，如氨或酰胺。在本项目中，将计算阳离子的O-D/O-H键的类似关系。这两个关系是有效的所有N-D或O-D键在所研究的液体无论是离子或分子。为了进一步判断预测的DQCC，我们还将测量这些耦合参数在固相中通过固态NMR。可靠的DQCC是从核磁共振氘四极弛豫速率确定旋转相关时间的先决条件。使用这种方法，第一个可靠的单粒子旋转相关时间可以确定离子液体及其混合物。他们将描述不同分子构型（如离子对或离子簇）的DIHB中涉及的N-D和O-D键的旋转动力学。相关时间将被确定为温度的函数，提供了重要的信息，在质子离子液体（PILs）的异质性。此外，流体动力学模型的适用性将被测试的液体系统，包括不同的中性或离子聚集体。第一个可靠的旋转相关时间对于离子液体的力场发展也是重要的。这已经在分子液体，如水和醇类中得到证实。

项目成果

Probing relaxation models by means of Fast Field-Cycling relaxometry, NMR spectroscopy and molecular dynamics simulations: Detailed insight into the translational and rotational dynamics of a protic ionic liquid

• DOI: 10.1016/j.molliq.2020.114207
• 发表时间: 2020-12-01
• 期刊: JOURNAL OF MOLECULAR LIQUIDS
• 影响因子: 6
• 作者: Overbeck, Viviane;Golub, Benjamin;Ludwig, Ralf
• 通讯作者: Ludwig, Ralf

Insights into the translational and rotational dynamics of cations and anions in protic ionic liquids by means of NMR fast-field-cycling relaxometry.

通过 NMR 快速场循环弛豫测量深入了解质子离子液体中阳离子和阴离子的平移和旋转动力学

• DOI: 10.1039/d0cp05440b
• 发表时间: 2021
• 期刊: Physical chemistry chemical physics : PCCP
• 作者: V. Overbeck;H. Schröder;A.-M. Bonsa;K. Neymeyr;R. Ludwig
• 通讯作者: R. Ludwig

Rotational correlation times, diffusion coefficients and quadrupolar peaks of the protic ionic liquid ethylammonium nitrate by means of 1H fast field cycling NMR relaxometry

• DOI: 10.1016/j.molliq.2020.114983
• 发表时间: 2021-01-15
• 期刊: JOURNAL OF MOLECULAR LIQUIDS
• 影响因子: 6
• 作者: Overbeck, Viviane;Appelhagen, Andreas;Ludwig, Ralf
• 通讯作者: Ludwig, Ralf

Hydrogen bonding in protic ionic liquids: structural correlations, vibrational spectroscopy, and rotational dynamics of liquid ethylammonium nitrate

质子离子液体中的氢键：液体乙基硝酸铵的结构相关性、振动光谱和旋转动力学

• DOI: 10.1088/1361-6455/aa9a9e
• 发表时间: 2018
• 期刊: Journal of Physics B: Atomic, Molecular and Optical Physics
• 作者: T. Zentel;V. Overbeck;D. Michalik;O. Kühn;R. Ludwig
• 通讯作者: R. Ludwig

The influence of like-charge attraction on the structure and dynamics of ionic liquids: NMR chemical shifts, quadrupole coupling constants, rotational correlation times and failure of Stokes-Einstein-Debye.

同电荷吸引力对离子液体结构和动力学的影响：NMR 化学位移、四极耦合常数、旋转相关时间和 Stokes-Einstein-Debye 失效

• DOI: 10.1039/c7cp06454c
• 发表时间: 2018
• 期刊: Physical chemistry chemical physics : PCCP
• 作者: A. Strate;V. Overbeck;V. Lehde;J. Neumann;A.-M. Bonsa;T. Niemann;D. Paschek;D. Michalik;R. Ludwig
• 通讯作者: R. Ludwig