Cluster Structure of Imidazolium Salts in Methanol Controlled by the Balance of Interactions: Cation-Anion, Cation-Solvent, and Anion-Solvent
Cluster Structure of Imidazolium Salts in Methanol Controlled by the Balance of Interactions: Cation-Anion, Cation-Solvent, and Anion-Solvent
复制标题
DOI：
10.2116/analsci.24.1311
复制
发表时间：
2008-10-01
影响因子：
1.6
通讯作者：
Wakisaka, Akihiro
中科院分区：
文献类型：
--
作者：
Kitaoka, Satoshi;Nobuoka, Kaoru;Wakisaka, Akihiro
我们利用电喷雾质谱仪研究了甲醇溶液中 1-丁基-3-甲基咪唑鎓卤化物 bmimX (X = Cl, Br, I) 的簇结构，该质谱仪专为分析从溶液中分离的簇而设计。在正离子模式实验中，溶剂化的 bmim(+)、bmim(+)(MeOH)(n) 和离子对簇 bmim(bmim(+)X(-))(m) 的比率取决于抗衡阴离子。对于bmimCl溶液，观察到少量溶剂化的bmim(+)簇，并且清楚地观察到离子对簇。另一方面，bmimBr和bmiml具有大阴离子时，溶剂化的bmim(+)簇明显增加，而离子对簇则显着减少。在负离子模式实验中，发现 Br- 与甲醇的溶剂化在 Cl-、Br- 和 I- 溶剂化中最为突出。考虑到离子-溶剂和离子-抗衡离子相互作用之间的平衡，这些结果得到了合理的解释。
We have studied the cluster structure of 1-butyl-3-methylimidazolium halide, bmimX (X = Cl, Br, I), in methanol solution by means of an electrospray mass spectrometer, which is specially designed for analysis of clusters isolated from solution. In positive ion mode experiments, the ratio of solvated bmim(+), bmim(+)(MeOH)(n), and ion-pair clusters, bmim(bmim(+)X(-))(m) was dependent on the counter anion. As for bmimCl solutions, few solvated bmim(+) clusters were observed, and the ion-pair clusters were clearly observed. On the other hand, bmimBr and bmiml with large anions, the solvated bmim(+) clusters increased obviously, and the ion-pair clusters were in turn remarkably decreased. In negative ion-mode experiments, the solvation for Br- by the methanol is found to be the most prominent among those for Cl-, Br-, and I-. These results were reasonably explained in consideration of the balance between ion-solvent and ion-counterion interactions.