Pyridine-hydrazone-controlled cyanide detection in aqueous media and solid-state: tuning the excited-state intramolecular proton transfer (ESIPT) fluorescence modulated by intramolecular NH⋯Br hydrogen bonding
Pyridine-hydrazone-controlled cyanide detection in aqueous media and solid-state: tuning the excited-state intramolecular proton transfer (ESIPT) fluorescence modulated by intramolecular NH⋯Br hydrogen bonding
复制标题
水介质和固态中吡啶腙控制的氰化物检测：调节分子内 NH–Br 氢键调制的激发态分子内质子转移 (ESIPT) 荧光
作者：
汪忠华
通过独特的激发态分子内质子转移（ESIPT）机制，合成了一种新的高效吡啶-腙取代萘酰亚胺受体4a-E，作为一种选择性比色和荧光化学传感器，用于在水环境中检测氰化物。在腙邻位的荧光团骨架上加成一个Br基团生成参比化合物（4b-E和4c-Z）。有趣的是，潜在的分子内NH⋯Br氢键可能与阴离子诱导的分子间NH⋯A−氢键竞争，导致戏剧性的ESIPT抑制。研究了探针4a-E和其他控制探针在固态中的高发射特性。另外，预装在试纸上的探针4a-E经过氰化物处理后，颜色变化明显，说明4a-E是一个可写平台。更重要的是，它在检测食品原料中的氰化物方面具有巨大的应用潜力，在实际水样中也表现出色。
A new efficient pyridine-hydrazone-substituted naphthalimide receptor 4a-E has been synthesized as a selective colorimetric and fluorescent chemosensor for cyanide sensing in aqueous environments through a unique excited-state intramolecular proton transfer (ESIPT) mechanism. The addition of a Br group to the fluorophore skeleton at the ortho-position of hydrazone generates reference compounds (4b-E and 4c-Z). Interestingly, the potential intramolecular NH⋯Br hydrogen bonding might compete with the anion-induced intermolecular NH⋯A− hydrogen bonding, resulting in dramatic ESIPT suppression. The high emission of probe 4a-E and other control probes in solid-state is also investigated. Moreover, probe 4a-E preloaded on test papers, upon cyanide treatment, shows obvious changes in color which demonstrates that 4a-E is a writable platform. More importantly, it exhibits great potential application for the detection of cyanide in food materials and excellent performance in real-world water samples.