Electrostatic spray of liquid : Study on the charged particles in the condensed phase

由于缺乏合适的方法学，离子溶剂化的研究是一个相当困难的任务。在这项工作中，研究了通过对液体施加强电场将溶解在液体中的离子萃取到气相中，并详细研究了离子在凝聚相中的物理化学行为。这将导致阐明溶剂效应，离子在凝聚相中的化学反应活性，溶剂化电子等。为了研究离子溶剂化的机理，用高压质谱仪研究了它们的热化学稳定性、结构和稳定性。结果表明，F~+对溶剂分子具有很强的反应性，常与溶剂分子形成共价键。相反，其他卤化物离子(Cl^-，Br^-，I^-)只被溶剂分子静电溶剂化。对于各种离子，水是一种更好的溶剂。我们指出，这是由于…的相互极化属于不同溶剂化壳层的n个以上的水配体加强了它们之间的相互作用(增强效应)。第一层中的醇分子与离子的相互作用比水分子更强。当B=烷基取代水和NH_3时，共轭碱B的气相质子亲和力与共轭离子的水合自由能BH^+‘S之间存在近似的线性关系，这意味着当共轭碱B具有较高的质子亲和力时，其共轭酸性离子BH更容易从凝聚相被萃取到气相。因此，电喷雾可以作为一种有用的工具来分析医药和农业领域中的溶剂化离子。所有检测到的主要离子都是假分子离子。这表明离子萃取过程非常温和。较少

The study on the ion solvation is a rather difficult task because of the lack of suitable methodology. In this work, the extraction of ions dissolved in the liquid into the gas phase by applying a strong electric field to the liquid are studied, and an information on the physicochemical behavior of ions in the condensed phase is investigated in detail. This will lead to the elucidation of the solvent effect, chemical reactivity of ions in the condensed phase, solvated electron, etc.In order to investigate the mechanism of ion solvation, the thermochemical stabilities, structures, and stabilities were studied using the high-pressure mass spectrometer. It was found that the F^- ion is highly reactive toward the solvent molecules and often forms the covalent bodn with them. In contrast, other halide ions (Cl^-, Br^-, I^-) are solvated only electrostatically by solvent molecules. Water is a superior solvent toward a variety of ions. We pointed out that this is due to the mutual polarizatio … More n of water ligands belonging to the different solvation shells which strengthens the interaction between them (enhancement effect). The alcohol molecules in the first shell experience stronger interaction with ions than watermolecules. However, the enhancement effect for alcohols is weaker than that for water, and thus alcohols are generally poorer solvents than water toward ions.An approximate linear relationship was found between gas-phase proton affinities of conjugate bases B's and free energies of hydration of conjugate ions BH^+'s for B = alkyl-substituted H_2O and NH_3. This means that if the conjugate base B has a higher proton affinity, its conjugate acid ion BH is easier to be extracted from the condensed phase to the gas phase. Thus the electrospray could be a useful tool for the analysis of solvated ions in the fields of medicine, pharmacy, and agriculture.The ions in solution were electrosprayed and mass-analysed. All of the detected major ions are found to be pseudo-molecular ions. This indicates that the ion extraction process is very mild. Less