Probing receptor-anion interactions by ratiometric chemosensors containing pyrrolecarboxamide interacting sites
Probing receptor-anion interactions by ratiometric chemosensors containing pyrrolecarboxamide interacting sites
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DOI：
10.1002/ejoc.200700294
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发表时间：
2007-08-01
影响因子：
2.8
通讯作者：
Sun, Shih-Sheng
中科院分区：
文献类型：
--
作者：
Chen, Chun-Lin;Lin, Tzu-Pin;Sun, Shih-Sheng
我们已经设计并合成了一系列的分子探针集成的酰胺和吡咯功能的阴离子识别和传感。这些探针分子和各种阴离子之间的相互作用进行了研究，以阐明电子效应对阴离子识别位点的影响。在阴离子存在下UV/维斯和荧光光谱的变化揭示了探针15典型地显示出对氰化物的强响应。此外，与阴离子相互作用后的比率现象的出现进一步增强了阴离子传感的光谱区分。通过1H-1 NMR滴定实验进一步探讨了探针分子与阴离子的反应机理。与探针强烈相互作用并在滴定过程中产生UV/维斯和荧光光谱的大变化的阴离子通常导致酰胺基团的去质子化，而弱相互作用的阴离子最初与酰胺和吡咯NH基团形成氢键，然后在较高的阴离子浓度下去质子化。然而，最弱的阴离子在滴定期间仅与酰胺和吡咯N-H基团形成两个或四个氢键。此外，探针2和3都能够在半水环境中以极高的选择性识别氰化物。形成共价键合的氰醇衍生物从氰化物除了电子缺乏的酰胺羰基中心是由于在半水环境中的探针2和3的有效性。((c)Wiley-VCH Verlag GmbH & Co. KGaA，69451魏因海姆，德国，2007）。
We have designed and synthesized a series of molecular probes integrating both an amide and a pyrrole functionality for anion-recognition and -sensing. The interactions between these probe molecules and various anions have been investigated to elucidate the influence of electronic effects on the anion-recognition site. Changes in the UV/Vis and fluorescence spectra in the presence of anions reveal that probes 15 typically display a strong response to cyanide. Moreover, the appearance of the ratiometric phenomenon upon interaction with anions further enhances spectral differentiation for anion-sensing. The mechanism for the reaction between the probe molecules and the anions has been further explored by H-1 NMR titration experiments. Anions strongly interacting with probes and producing large changes in the UV/ Vis and fluorescence spectra during the titration usually result in deprotonation of the amide group, whereas weakly interacting anions initially form hydrogen bonds with amide and pyrrole NH groups followed by deprotonation at higher anion concentrations. The weakest anions, however, form only two or four hydrogen bonds with the amide and pyrrole N-H groups during the titrations. Moreover, both probes 2 and 3 are able to recognize cyanide in a semi-aqueous environment with extremely high selectivity. The formation of covalently bonded cyanohydrin derivatives from cyanide addition to an electron-deficient amide carbonyl center is attributed to the effectiveness of probes 2 and 3 in a semi-aqueous environment. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).