Functionality-oriented molecular gels: synthesis and properties of nitrobenzoxadiazole (NBD)-containing low-molecular mass gelators.
Functionality-oriented molecular gels: synthesis and properties of nitrobenzoxadiazole (NBD)-containing low-molecular mass gelators.
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DOI：
10.1039/c4sm01869a
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发表时间：
2014-10
期刊：
影响因子：
3.4
通讯作者：
Hang Yu;Yanchao Lü;Xiang‐Lei Chen;Kaiqiang Liu;Yu Fang
中科院分区：
文献类型：
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作者：
Hang Yu;Yanchao Lü;Xiang‐Lei Chen;Kaiqiang Liu;Yu Fang
通过在硝基苯并恶二唑（NBD）和胆固醇（Chol）单元之间引入d/l-苯丙氨酸，合成了两种含NBD的胆固醇衍生物。化合物分别表示为和。在34种液体中测试了它们的成胶行为。结果表明，连接基团的手性对两种化合物的成胶能力和凝胶性能有很大的影响。SEM研究表明，/DMSO凝胶中的凝胶因子聚集成均匀的纤维状结构。FTIR、（1）H NMR和UV-Vis光谱研究表明，分子间氢键和π-π堆积是促进凝胶形成的两个主要驱动力。有趣的是，/DMSO凝胶表现出快速和可再现的凝胶-溶胶相变和荧光淬灭后，引入氨。此外，凝胶和荧光发射都可以在引入的氨气蒸发后完全恢复。光谱和模型系统的研究揭示了氨与化合物的NBD单元的硝基基团的关联，这被认为是凝胶系统的化学响应的主要原因。在此基础上，制备了氨敏感膜并制成了器件。此外，还开发了一种基于设备的概念性“氨泄漏”监测仪器。初步测试表明，该系统的性能是非常好的，一个典型的和有说服力的例子，以显示分子凝胶的重要的现实生活中的应用。
Two nitrobenzoxadiazole (NBD)-containing cholesteryl (Chol) derivatives were prepared by introducing d/l-phenylalanine into the linkers between the NBD and Chol units. The compounds were denoted as and , respectively. The gelation behaviors of them were tested in 34 liquids. It was found that the chirality of the linkers shows a great effect on the gelation ability and the gel properties of the two compounds. SEM studies demonstrated that the gelator in the gel of /DMSO aggregated into uniform fibrous structures. FTIR, (1)H NMR and UV-Vis spectroscopy measurements revealed that intermolecular hydrogen bonding and π-π stacking are two main driving forces to promote the gel formation. Interestingly, the /DMSO gel exhibits rapid and reproducible gel-sol phase transition and fluorescence quenching upon introduction of ammonia. Furthermore, both the gel and the fluorescence emission could be fully recovered upon evaporation of the ammonia gas introduced. Spectroscopy and model system studies revealed the association of ammonia with the nitro group of the NBD unit of the compound, which is recognized as the main reason for the chemical responses of the gel system. On the basis of the discovery, an ammonia sensing film had been fabricated and made into a device. Furthermore, a device-based and conceptual "ammonia leaking" monitoring instrument was developed. A preliminary test demonstrated that the performance of the system is exceptionally good, a typical and persuasive example to show the important real-life applications of molecular gels.