School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala 695016 (India) http://kms514.wix.com/kmsgroup.
Angew Chem Int Ed Engl. 2015 Oct 5;54(41):12078-82. doi: 10.1002/anie.201506544. Epub 2015 Aug 21.
A new class of organogelators having a cyclohexane-1a,3a-diol motif capable of congealing non-polar liquids was developed. These gelators underwent crystallization at low concentration and gelation above the critical gelation concentration (CGC) in the same solvent. The crystals and gel fibers were analyzed by single crystal XRD and PXRD respectively, which revealed their different modes of assembly. The XRD studies and thermogravimetric analysis (TGA) confirmed that the crystals contain a water of crystallization whereas the gel fibers do not. A systematic study revealed that when the concentration of the gelator exceeds that of adventitious water in the solvent, it congeals the solvent and when the concentration of the gelator is less than water, it undergoes crystallization. This unprecedented stoichiometric sensing behavior in deciding the mode of self-assembly offers a handle to opt between mutually competing gelation and crystallization. We have confirmed that the system can be biased to congeal or crystallize by varying the amount of water.
开发了一类具有环己烷-1a,3a-二醇结构的新型有机凝胶因子，能够凝结非极性液体。这些凝胶因子在低浓度下结晶，在同一溶剂中超过临界凝胶浓度（CGC）时凝胶。通过单晶 XRD 和粉末 XRD 分别对晶体和凝胶纤维进行了分析，揭示了它们不同的组装方式。XRD 研究和热重分析（TGA）证实晶体中含有结晶水，而凝胶纤维中则没有。系统研究表明，当凝胶因子的浓度超过溶剂中偶然水的浓度时，它会凝结溶剂，而当凝胶因子的浓度小于水时，它会结晶。这种在决定自组装模式方面前所未有的化学计量感应行为提供了一种在相互竞争的凝胶化和结晶之间进行选择的方法。我们已经通过改变水的量证实了该体系可以偏向于凝结或结晶。
