Abstract

The molecular structure, electron density topography, vibrational frequencies and molecular interactions of the choline acetate ion pair were investigated using M05-2X based density functional approach. Different conformers of choline acetate ion pair based on molecular interactions were obtained in the gas phase and also in a solvent environment. The lowest energy conformer showed the presence of both O–H···O and C–H···O interactions. A strong binding between the cation and anion was observed in the lowest energy conformers through ion pairing free energies. The O–H···O and C–H···O interactions were weakened from the gas phase to the condensed phase.

Graphic abstract

Molecular graphs of choline acetate ion pair in gas phase (G1) and in dielectric continuum (S2).

中文翻译：

---

2-羟乙基-三甲基乙酸铵（乙酸胆碱）离子对中的分子相互作用

摘要

使用基于M05-2X的密度泛函方法研究了胆碱乙酸盐离子对的分子结构，电子密度分布，振动频率和分子相互作用。在气相中以及在溶剂环境中，基于分子相互作用获得了不同构型的胆碱乙酸盐离子对。最低能量构象异构体表明同时存在O–H···O和C–H···O相互作用。通过离子对自由能在最低能构象中观察到阳离子和阴离子之间的牢固结合。从气相到冷凝相，OH-··O和CHH···O的相互作用减弱。

图形摘要

气相（G1）和介电连续体（S2）中的胆碱乙酸盐离子对的分子图。