【作者】 尚红杏； 王宇飞； 姜世梅；

【Author】 Hongxing Shang;Yufei Wang;Shimei Jiang;State Key Laboratory of Supramolecular Structure and Materials,Jilin University;

【机构】 吉林大学超分子结构与材料国家重点实验室；

【摘要】 近年来,具有发光调控的超分子纳米材料被广泛的应用于响应环境的物理刺激(热、光、声和机械力等)和化学刺激(酸碱、离子、氧化还原、天然产物和酶等)。超分子凝胶作为一类智能响应的软物质材料,既可以组装形成三维网络结构,又可以赋予其良好的发光性质。我们将端基修饰吡啶基团的氰基苯乙烯结构与传统的凝胶因子胆固醇结合,构筑了含有不同连接基团的两类聚集诱导发光凝胶(Chol-CN-1和Chol-CN-2)。凝胶因子表现出聚集诱导发光增强,聚集诱导圆二色性以及自组装螺旋纤维的性质。针对Chol-CN-1,进行了光照及酸碱刺激的研究。氰基苯乙烯具有典型的二苯乙烯结构,可以在紫外光照下产生反式到顺式结构的转变,光照后的凝胶发生塌陷并伴随着荧光的蓝移(蓝绿色转变为蓝紫色),通过核磁氢谱证明了两种构型的转变。由于端基的吡啶基团可以迅速质子化,因此凝胶因子在溶液态和凝胶态对三氟乙酸和三乙胺具有可逆的酸碱刺激响应。在溶液态,酸碱的响应在荧光上呈现比率型的检测方式;在凝胶态,酸碱的可逆刺激伴又随着凝胶的坍塌及重新形成。为了实现更方便快捷的应用,具有三维网络结构的干凝胶薄膜可以快速对挥发性的三氟乙酸进行检测。在荧光上,从蓝绿色逐步渐变为橙黄色,检测限低至5.56ppb,并且响应时间达到1.66 s。综上,我们合成了一类聚集诱导发光增强性质的凝胶,实现了其超分子手性组装,光的响应以及构筑了一个简单和低消耗检测酸性挥发气体的方法。更多还原

【Abstract】 Supramolecular nanomaterials have recently been developed to tune luminescence systems responding to important environmental stimuli including physical stimuli,such as heat,light,sound and mechanical forces and chemical stimuli,such as acid-base,ions,redox,nature species and enzymes.Supramolecular gels have become fascinating soft materials not only because of their elegant architectures combining three-dimensional network properties,but also owing to their substantial applications such as in sensing luminescent devices.In this work,we report two kinds of supramolecular gels assembled from a cyanostilbene with steroidal group.The flexible spacer attached via ester group can form stable gel,while the flexible spacer attached via amide group form unstable gel.The gelators exhibit aggregation-induced enhanced emission(AIEE),aggregation-induced circular dichroism(AICD) and the capacity to self-assemble into helical nanofibers.The luminescence of the AIEE gel transform via light and acid-base stimuli successfully and concomitant gel-to-sol transition.Photoresponsive behavior was studied in dilute solution,the aggregation state and gel state,which realized the gel-to-sol transition accompanying fluorescence emission switching(blue-green to blue-violet).Then,the AIEE gel containing pyridine unit exhibits superior detection capability for TFA(volatile acid vapor) in the xerogel film when compared to that in the solution state and gel state.The sensing process can also be reversed by TFA and TEA.Because the gelator demonstrates the measurement of emission intensities at two different wavelengths,the detection exhibits the ratiometric fluorescence detection of TFA vapors,which allow for the correction for environmental effects.The xerogel film coated on quartz plate detects TFA with a detection limit of 5.56 ppb and the response time of 1.66 s.This is a simple and low-cost method for the detection of volatile acid vapor in the xerogel film,taking advantage of the unique molecular packing of a supromolecular gelator and the associated AIEE photophysical properties.更多还原