Towards the development of colorimetric probes to discriminate between isomeric dicarboxylates.
Towards the development of colorimetric probes to discriminate between isomeric dicarboxylates.
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DOI：
10.1002/anie.200390178
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发表时间：
2003-02
影响因子：
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通讯作者：
F. Sancenón;R. Martínez‐Máñez;M. Miranda;M. Seguí;J. Soto
中科院分区：
文献类型：
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作者：
F. Sancenón;R. Martínez‐Máñez;M. Miranda;M. Seguí;J. Soto
基于超分子概念的新型化学传感器的开发是当前感兴趣的领域。[1]大量的工作已经致力于获得特定的化学传感器，能够改变，与目标客人络合后，响应于分子配位事件的一个或几个宏观性质。荧光[2]和吸光度[3]的变化是光学化学传感器开发中使用的输出信号。尽管已经开发了许多用于感测金属离子的显色受体，[4]在文献中描述的基于识别方法的阴离子的显色受体很少。[5]大多数受体都是为了无机阴离子的比色传感而开发的，[6]而很少有设计用于识别有机阴离子，[7]特别是在水性环境中。因此，开发用于这些物种的显色试剂仍然是一个挑战。在这种情况下，作为这一领域的一个进步，我们现在希望报告显色系统之间的某些有机异构体（顺/反和邻/Meta/帕拉二羧酸）的比色歧视。由于异构体的化学和物理性质相当相似，因此它们的区分通常是一项困难的任务。据我们所知，我们在这里展示的例子是第一个基于超分子的比色探针，用于检测异构阴离子。大多数已知的比色阴离子化学传感器是基于含有偶联到显色信号单元的阴离子配位位点的主体分子。在这些受体中，阴离子的配位通常会改变显色基团的电荷转移带，从而导致裸眼检测到阴离子。一种不同的方法涉及使用阴离子诱导的反应，该反应可以是可逆的或不可逆的。[8]我们最近报道了使用一个这样的阴离子诱导的可逆反应的ATP在水/有机溶剂混合物中的选择性检测。[9]该体系是基于黄色的1，3，5-三芳基-2-烯-1，5-二酮环化为洋红的吡喃阳离子。在DMF中，2，6-二苯基吡喃高氯酸盐与苯胺衍生物在1508 ℃发生亲电芳香取代反应，合成了一类1，3，5-三芳基-2-烯-1，5-二酮。随后在氧化铝上进行柱层析，得到受体L1和L 8，产率约为35%。L1和L 8的UV/维斯光谱非常相似，中心在370 - 380 nm左右的谱带，这表明它们具有明亮的黄色。化合物L1和L 8的结构示于方案1中。
The development of new chemosensors based on supramolecular concepts is a field of current interest.[1] A significant amount of work has been devoted to obtain specific chemosensors that are able to change, upon complexation with the target guests, one or several macroscopic properties in response to the molecular coordination event. Changes in fluorescence [2] and in absorbance [3] are the output signals used in the development of optical chemosensors. Although a number of chromogenic receptors for the sensing of metal ions have been developed,[4] very few chromogenic receptors for anions have been described in the literature that are based on recognition approaches.[5] Most of the receptors have been developed for the colorimetric sensing of inorganic anions,[6] whereas very few have been designed for recognition of organic anions,[7] particularly in aqueous environments. Thus, the development of chromogenic reagents for such species remains a challenge. In this context, and as an advancement of this field, we wish now to report a chromogenic system for the colorimetric discrimination between certain organic isomers (cis/trans and ortho/meta/para dicarboxylates). Differentiation of isomers is, in general, a difficult task because of their rather similar chemical and physical properties. To the best of our knowledge, the examples we show here are the first supramolecular-based colorimetric probes for the detection of isomeric anions. Most of the known colorimetric anion chemosensors are based on host molecules containing anion coordination sites coupled to chromogenic signaling units. In those receptors, coordination of the anion usually modifies the charge-transfer band of the chromogenic group resulting in™ naked-eye∫ anion detection. A different approach involves the use of anion-induced reactions that can be either reversible or irreversible.[8] We have recently reported the use of one such anion-induced reversible reaction for the selective detection of ATP in water/organic solvent mixtures.[9] The system was based on the cyclization of yellow 1, 3, 5-triarylpent-2-en-1, 5-diones to the magenta pyrylium cation. A family of 1, 3, 5-triarylpent-2-en-1, 5-diones were synthesized by electrophilic aromatic substitution of the corresponding aniline derivative with 2, 6-diphenylpyrylium perchlorate in DMF at 1508C. Subsequent column chromatography on aluminum oxide afforded the receptors L1ąL8 in approximately 35% yield. The UV/Vis spectra of L1ąL8 are very similar, with a band centered at around 370ą380 nm, which is indicative of their brightly yellow color. The structures of the compounds L1ąL8 are shown in Scheme 1.