Yang Hong, Yi Tao, Zhou Zhiguo, Zhou Yifeng, Wu Juncheng, Xu Miao, Li Fuyou, Huang Chunhui
Department of Chemistry & Laboratory of Advanced Materials, Fudan University, Shanghai 200433, People's Republic of China.
Langmuir. 2007 Jul 17;23(15):8224-30. doi: 10.1021/la7005919. Epub 2007 Jun 20.
Bisurea-functionalized naphthalene organogelators via cooperative hydrogen bonding and pi-pi stacking interaction were designed and synthesized. The gelators showed excellent gelling capability in various solvents and performed switchable fluorescence in the gel state. The fluorescent emission of these compounds strongly depends on the aggregation of the fluorophore and is very sensitive to the temperature and chemical stimuli. A stronger and red-shifted emission was found in the gel state compared with the original solution. The gel-sol transition of the systems, as well as the fluorescent emission, is reversibly controlled by a change of the temperature or upon alternative addition of fluoride anions and protons. The influence of fluoride anions on the fluorescence and gel-sol processes is a result of the dissociation of intermolecular hydrogen bonds by bonding of fluoride anions with urea groups of the gelator. The obtained sol is turned to the gel state again upon addition of trifluoroacetic acid. Furthermore, polarizing optical microscopy and small-angle X-ray scattering indicated that the gelator exhibited the liquid crystalline property and displayed the column phase.
通过协同氢键和π-π堆积相互作用设计并合成了双脲功能化萘有机凝胶因子。这些凝胶因子在各种溶剂中表现出优异的胶凝能力，并在凝胶状态下具有可切换荧光。这些化合物的荧光发射强烈依赖于荧光团的聚集，并且对温度和化学刺激非常敏感。与原始溶液相比，在凝胶状态下发现发射更强且发生红移。体系的凝胶-溶胶转变以及荧光发射可通过温度变化或交替添加氟离子和质子来可逆控制。氟离子对荧光和凝胶-溶胶过程的影响是由于氟离子与凝胶因子的脲基团结合导致分子间氢键解离。加入三氟乙酸后，得到的溶胶又转变为凝胶状态。此外，偏光显微镜和小角X射线散射表明，凝胶因子具有液晶性质并呈现柱状相。
