Light-Triggered Transformation of Molecular Baskets into Organic Nanoparticles
Light-Triggered Transformation of Molecular Baskets into Organic Nanoparticles
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DOI：
10.1002/chem.201803693
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发表时间：
2019-01-02
影响因子：
4.3
通讯作者：
Badjic, Jovica D.
中科院分区：
文献类型：
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作者：
Border, Sarah E.;Pavlovic, Radoslav Z.;Badjic, Jovica D.
发现新型和功能性的光响应材料对于改善分子的控制释放和清除有毒化合物以净化环境或设计化学传感器具有重要意义。在这项研究中，我们报道了篮子1(6-)的光诱导脱羧基，它的边缘含有三个谷氨酸。这种凹形化合物在水环境(pH为7.0的30 mM磷酸盐缓冲液)中是单体(H-1核磁共振剂量，DLS)，谷氨酸残基在其边缘随机取向(H-1核磁共振和MM-OPLS3)。1(6-)的辐射(300 Nm)导致其α-羧酸盐被完全去除，得到具有伽玛-羧酸盐的两亲性2(3-)。H-1核磁共振谱和电喷雾质谱观察到光化学转化是一种连续的反应，生成的是一种或两种脱羧基的产物。两亲性2(3-)是一种预先组织的分子(MM-OPLS3)，它在水中聚集成有机纳米粒子(直径约50-200 nm；DLS，透射电子显微镜和低温电子显微镜)，其临界聚集浓度为12微米(UV/Vis)。由于单体1(6-)到纳米粒子2(3-)的转变是用光触发的，我们推测这种软材料的刺激响应形成适合于纳米技术应用，如目标化合物的控制释放或清除。
Discovering novel and functional photoresponsive materials is of interest for improving controlled release of molecules and scavenging toxic compounds for cleaning our environment or designing chemosensors. In this study, we report on the photoinduced decarboxylation of basket 1(6-), containing three glutamic acids at its rim. This concave compound is, in an aqueous environment (30 mm phosphate buffer at pH 7.0), monomeric (H-1 NMR DOSY, DLS) with glutamic acid residues randomly oriented about its rim (H-1 NMR and MM-OPLS3). The irradiation (300 nm) of 1(6-) leads to the exclusive removal of its alpha-carboxylates to give amphiphilic 2(3-) possessing gamma-carboxylates. The photochemical transformation is a consecutive reaction with mono- and bis-decarboxylated products observed with H-1 NMR spectroscopy and ESI mass spectrometry. Amphiphilic 2(3-) is a preorganized molecule (MM-OPLS3) that, in water, aggregates into organic nanoparticles (ca. 50-200 nm in diameter; DLS, TEM and cryo-TEM) having a critical aggregation concentration of 12 mu m (UV/Vis). As the transition of monomeric 1(6-) into nanoparticulate 2(3-) is triggered with light, we reasoned that stimuli-responsive formation of the soft material lends itself to nanotechnology applications such as controlled release or scavenging of targeted compounds.