微水化对离子被二-18-皇冠-6封装的作用
Yoshiya Inokuchi1, Takayuki Ebata, Thomas R Rizzo
1Department of Chemistry, Graduate School of Science, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, Japan.
Journal of the American Chemical Society
|January 16, 2014
概括
我们研究了含离子 (K+) 的化二-18-皇冠-6 (DB18C6) 复合体. 多个K+复合体构造增强了离子捕获,与Rb+和Cs+复合体不同,它们显示单个异构体.
科学领域:
- 物理化学 物理化学
- 超分子化学 超分子化学
- 频谱学是一种光谱学.
背景情况:
- 丁-18-皇冠-6 (DB18C6) 是一种以结合性金属离子而闻名的宏环.
- 了解金属宏循环复合物的水化对于离子选择性和复合物稳定性至关重要.
- 合规灵活性会影响主机-客户系统的绑定特性.
研究的目的:
- 为了研究水合-DB18C6复合物的电子和振动光谱.
- 确定K+,Rb+和Cs+复合体与DB18C6和水分子的对象的数量和结构.
- 阐明离子大小和水合在这些复合物的构造性行为中的作用.
主要方法:
- 冰冷的22极离子陷光谱仪测量电子和振动光谱.
- 量子化学计算以分析光谱数据并确定符合结构.
- 对K+,Rb+和Cs+复合物的比较光谱分析.
主要成果:
- K+•DB18C6•(H2O) n复合体 (n=1-3) 由于K+-水相互作用较弱和K+-DB18C6尺寸匹配最优,因此表现出多个对象.
- 在Rb+•DB18C6•(H2O) 3和Cs+•DB18C6•(H2O) 3复合体中,每个复合体只显示一个合规器.
- 对于n=4-5,K+复合物形成一个环状的水结构,导致一个观察到的同位素和K+从空洞中移动.
- 多个K+构造为离子捕获提供了的优势.
结论:
- K+与DB18C6腔体之间的尺寸兼容性决定了水合复合物的结构多样性.
- 水在稳定特定形状和影响离子-宏观循环相互作用方面发挥着关键作用.
- 在K+复合体中观察到的构造多样性增强了它们对K+对较大的金属离子的选择性.
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