已经开发了一种新的由2,6-二氨基吡啶衍生的双苏糖凝胶剂。通过在溶剂中形成细长的自组装纤维,它可以有效地凝胶化常见的有机和液晶(LC)溶剂。X射线晶体学和1 H NMR测量表明,基于吡啶的Bisurea化合物中的两个脲基形成不同的氢键模式。两个尿素单元中的一个参与与吡啶基氮的分子内氢键结合,而另一个尿素单元形成分叉的分子间氢键合。这种氢键结构是纤维自组装以及有效凝胶化的关键。此外,基于吡啶基胶凝剂的LC凝胶具有良好的电光特性。
A new bisurea gelator derived from 2,6-diaminopyridine has been developed. It efficiently gelates common organic and liquid crystalline (LC) solvents by forming elongated self-assembled fibres in solvents. X-Ray crystallography and 1H NMR measurements reveal that two urea groups in pyridine-based bisureacompounds form different hydrogen bonding patterns. One of two urea units is involved in intramolecular
已经开发了一种新的由2,6-二氨基吡啶衍生的双苏糖凝胶剂。通过在溶剂中形成细长的自组装纤维,它可以有效地凝胶化常见的有机和液晶(LC)溶剂。X射线晶体学和1 H NMR测量表明,基于吡啶的Bisurea化合物中的两个脲基形成不同的氢键模式。两个尿素单元中的一个参与与吡啶基氮的分子内氢键结合,而另一个尿素单元形成分叉的分子间氢键合。这种氢键结构是纤维自组装以及有效凝胶化的关键。此外,基于吡啶基胶凝剂的LC凝胶具有良好的电光特性。
Supramolecular Balance: Using Cooperativity To Amplify Weak Interactions
作者:Mihaela Roman、Caroline Cannizzo、Thomas Pinault、Benjamin Isare、Bruno Andrioletti、Paul van der Schoot、Laurent Bouteiller
DOI:10.1021/ja105717u
日期:2010.12.1
Gathering precise knowledge on weak supramolecular interactions is difficult yet is of utmost importance for numerous scientific fields, including catalysis, crystal engineering, ligand binding, and protein folding. We report on a combined theoretical and experimental approach showing that it is possible to vastly improve the sensitivity of current methods to probe weak supramolecular interactions in solution. The concept consists of using a supramolecular platform involving a highly cooperative configurational transition, the perturbation of which (by the modification of the molecular building blocks) can be monitored in a temperature scanning experiment. We tested this concept with a particular bisurea platform, and our first results show that it is possible to detect the presence of interaction differences as low as 60 J/mol, which may be due to steric repulsion between vinyl and alkyl groups or may be the result of solvation effects.