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.

我们想要确定离子液体 (IL) 及其混合物的双离子氢键 (DIHB) 中涉及的 N-D 和 O-D 分子矢量的 NMR 氘核四极耦合常数 (DQCC) 和旋转相关时间。通常，由于 NMR 时间尺度上的快速质子交换，需要昂贵的 15N 或 17O 增强质子弛豫时间实验来确定液相的准确 DQCC。为了避免同位素取代化合物的合成要求高且成本高昂，我们最近开发了一种根据密度泛函理论 (DFT) 计算的 N-D DQCC 与离子液体簇内 N-H 质子化学位移之间的关系推导 DQCC 的方法。通过简单测量质子化学位移，我们可以在液相中获得精确的 DQCC。无论温度和溶剂的影响如何，该方法都是有效的。作为概念证明，我们可以证明这种关系也适用于分子液体，例如氨或酰胺。在本项目中，将计算阳离子的 O-D/O-H 键的类似关系。这两种关系对于所研究的离子或分子液体中的所有 N-D 或 O-D 键均有效。为了进一步判断预测的 DQCC，我们还将通过固态 NMR 测量固相中的这些耦合参数。可靠的 DQCC 是根据 NMR 氘核四极弛豫率确定旋转相关时间的先决条件。使用这种方法，可以确定离子液体及其混合物的第一个可靠的单粒子旋转相关时间。他们将描述不同分子构型（例如离子对或离子簇）中 DIHB 所涉及的 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，提供有关质子离子液体 (PIL) 异质性的重要信息。此外，还将测试流体动力学模型对于包括不同中性或离子聚集体的液体系统的适用性。第一个可靠的旋转相关时间对于离子液体的力场发展也很重要。这一点早先已在水和醇等分子液体中得到证实。

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