Extended and Contorted Conformations of Alkanediammonium Ions in Symmetrical α,α′,δ,δ′-Tetramethylcucurbit[6]uril Cavity
作者:Bo Yang、Li-Mei Zheng、Zhong-Zheng Gao、Xin Xiao、Qian-Jiang Zhu、Sai-Feng Xue、Zhu Tao、Jing-Xin Liu、Gang Wei
DOI:10.1021/jo502255x
日期:2014.11.21
Binding interactions between symmetrical α,α′,δ,δ′-tetramethylcucurbit[6]uril (TMeQ[6]) and a series of alkyldiammonium ions in aqueous solution and in the solid state were investigated by 1H NMR spectroscopy, MALDI-TOF mass spectrometry, X-ray crystallography, and isothermal titration calorimetry (ITC). Their 1H NMR spectra reveal that the actual binding behaviors vary depending upon the alkyl chain
通过1 H NMR光谱,MALDI-TOF研究了对称的α,α',δ,δ'-四甲基葫芦[6]尿素(TMeQ [6])与一系列烷基二铵离子在水溶液中和固态时的结合相互作用质谱,X射线晶体学和等温滴定热量法(ITC)。他们的11 H NMR光谱表明,实际的结合行为根据烷基链的长度而变化。他们的单晶X射线衍射分析表明,来宾1,2-乙烷二铵位于TMeQ [6]门的外部,而其他四个烷基二铵来宾可以容纳在TMeQ [6]腔中,形成1:1夹杂物复合体。最重要的是,长链烷基二铵(1,8-辛烷二铵和1,10-癸二铵)在TMeQ [6]腔内结合时具有扭曲的构象。另外,ITC实验表明,烷基二铵客体与TMeQ [6]的络合主要是由焓驱动的,这得益于离子-偶极相互作用。