Direct experimental observation of mesoscopic fluorous domains in fluorinated room temperature ionic liquids
Direct experimental observation of mesoscopic fluorous domains in fluorinated room temperature ionic liquids
复制标题
DOI：
10.1039/c7cp01971h
复制
发表时间：
2017-05-28
影响因子：
3.3
通讯作者：
Russina, O.
中科院分区：
文献类型：
--
作者：
Lo Celso, F.;Yoshida, Y.;Russina, O.
氟化室温离子液体（FRTIL）代表一类溶剂介质，由于其IL特异性性质以及源自其氟性质的特征而引起极大关注。中长的氟尾在极性环境中构成了明确的非极性部分。类似于烷基尾的情况，预期此类链导致形成自组装氟域。然而，到目前为止，还没有直接的实验观察到这种结构异质性的存在，在纳米尺度上。我们在这里报告的第一个实验证据的存在下，介观空间隔离的氟化域，高度互补的X射线和中子散射数据集（突出后者的重要性探针）和NMR光谱的基础上。使用原子分子动力学模拟解释数据，强调存在的自组装机制，提供隔离的氟域，其中可以发生氟化化合物的优先溶解，从而为几个智能应用铺平了道路。
Fluorinated room temperature ionic liquids (FRTILs) represent a class of solvent media that are attracting great attention due to their IL-specific properties as well as features stemming from their fluorous nature. Medium-to-long fluorous tails constitute a well-defined apolar moiety in the otherwise polar environment. Similarly to the case of alkyl tails, such chains are expected to result in the formation of self-assembled fluorous domains. So far, however, no direct experimental observation has been made of the existence of such structural heterogeneities on the nm scale. We report here the first experimental evidence of the existence of mesoscopic spatial segregation of fluorinated domains, on the basis of highly complementary X-ray and neutron scattering data sets (highlighting the importance of the latter probe) and NMR spectroscopy. Data are interpreted using atomistic molecular dynamics simulations, emphasizing the existence of a self-assembly mechanism that delivers segregated fluorous domains, where preferential solubilisation of fluorinated compounds can occur, thus paving the way for several smart applications.