碳氧功能化的离子液体冷离子复合体中的结构图案通过多纳秒延长紧结复制品交换探索分子动力学模拟
Lena Möhring1, Jule Kristin Philipp1, Dietmar Paschek1
1Institut fur Chemie, Physikalische und Theoretische Chemie, Universitat Rostock, Albert-Einstein-Stra e 27, D-18059 Rostock, Germany.
The journal of physical chemistry. A
|August 16, 2025
概括
强键 (HBs) 在离子液体中形成双键的阴离子二极体,从晶体持续到液态. 这些HB图案在更高的温度下分解,显示出它们的显著强度,尽管有排斥力.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
背景情况:
- 离子液体 (ILs) 是可调节的溶剂,具有由分子间相互作用控制的独特特性.
- 碳氧功能化ILs表现出强烈的,定向的键 (HBs),影响其结构和行为.
- 在碳酸中观察到双键的阴离子二极体 (c+=c+),并被假设在ILs中.
研究的目的:
- 为了研究碳氧功能化的离子液体中双键的阴离子二极体 (c+=c+) 的存在和稳定性.
- 确定这些HB图案的温度依赖的结构转变和能量贡献.
- 阐明结在离子液体相位行为中的作用.
主要方法:
- 红外 (IR) 光谱分析CO拉伸振动并识别HB动机.
- 低温离子振动预分离光谱检测气相复合物.
- 扩展紧固结合复制品交换分子动力学 (xTB-REMD) 模拟以研究从30到545 K的热平衡.
主要成果:
- 在液态和晶态中确定了双结合的阴离子二极体 (c+=c+),在气相复合体中持久.
- 在大约80K以下, (c+=c+) HB动图完全占主导地位,阴离子采用类似的配置.
- 在126 K发生一个明显的相变,其中 (c+=c+) HB动机转化为基本上没有HBs的状态,过渡度为-9.4 kJ mol-1.
结论:
- 强大的定向键对于决定碳氧功能化的离子液体结构至关重要.
- 双键的阴离子二聚体 (c+=c+) 是一个稳定的动机,显著影响IL的热行为.
- 尽管Coulombic排斥, (c+=c+) HB动机表现出显著的稳定性,影响IL的相变.
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