Choline chloride (ChCl) is used extensively as a hydrogen bond donor in deep eutectic solvents (DESs). However, determining its melting properties experimentally is challenging due to decomposition upon melting, leading to widely varying literature values. Accurate melting properties are crucial for understanding the solid–liquid phase behavior of ChCl-containing DESs. Here, we employ molecular dynamics simulations to compute the phase transitions of ChCl, testing a variety of atomistic force fields. We find that the results are sensitive to the choice of force field, but a melting temperature of 627 K and a melting enthalpy of 7.8 kJ/mol seem most reasonable, in good agreement with some literature values. We suggest these as the likely melting properties of ChCl, though the results are tentative due to limited experimental data for the liquid ChCl phase.

中文翻译：

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通过分子动力学模拟评估氯化胆碱的熔融和固-固转变特性


氯化胆碱 （ChCl） 广泛用作深共熔溶剂 （DES） 中的氢键供体。然而，由于熔化时分解，通过实验确定其熔融特性具有挑战性，导致文献价值差异很大。准确的熔解特性对于了解含 ChCl 的 DES 的固-液相行为至关重要。在这里，我们采用分子动力学模拟来计算 ChCl 的相变，测试各种原子力场。我们发现结果对力场的选择很敏感，但 627 K 的熔化温度和 7.8 kJ/mol 的熔融焓似乎最合理，与一些文献值非常吻合。我们认为这些是 ChCl 可能的熔融特性，但由于液态 ChCl 相的实验数据有限，结果是暂定的。