Conversion of thioureas to fluorescent isothiouronium-based photoinduced electron transfer sensors for oxoanion sensing
作者:Seiichi Nishizawa、Ying-Yu Cui、Masakazu Minagawa、Kotaro Morita、Yuichi Kato、Shinichiro Taniguchi、Ryo Kato、Norio Teramae
DOI:10.1039/b201704k
日期:2002.4.29
A convenient conversion is described of thiourea-based receptors to fluorescent isothiouronium-based photoinduced electron transfer (PET) sensors for oxoanion sensing. Naphthalene- or anthracene-functionalized mono-isothiouroniums are synthesized from the corresponding thioureas, in which the fluorophore is connected to the sulfur atom of the thiourea moiety by a methylene or an ethylene spacer. Even though all of the isothiouroniums with a methylene spacer readily decompose in MeOH upon excitation of the fluorophore moiety, the isothiouronium with an ethylene spacer shows good stability under identical conditions. The naphthyl isothiouronium with an ethylene spacer shows a significant fluorescence enhancement upon formation of a 1 ∶ 1 complex with oxoanions in MeOH, and the selectivity follows the order of hydrogen phosphate > acetate ≫ dihydrogen phosphate ≫ chloride. The results in the present work indicate that various types of fluorescent PET sensors might
be readily obtainable from non-fluorescent thiourea-based receptors by the introduction of appropriate fluorophores at the sulfur atom of thiourea-binding sites.
本文介绍了一种将基于硫脲的受体转换为基于异硫脲的荧光光诱导电子转移(PET)传感器的简便方法,用于氧阴离子传感。萘或蒽功能化的单异硫脲由相应的硫脲合成,其中荧光团通过亚甲基或亚乙烯间隔物与硫脲分子的硫原子连接。尽管所有带有亚甲基间隔物的异硫脲都很容易在 MeOH 中因荧光团分子的激发而分解,但带有乙烯间隔物的异硫脲在相同条件下表现出良好的稳定性。带有乙烯间隔的萘基异硫脲在 MeOH 中与氧阴离子形成 1 ∶ 1 复合物时,荧光会明显增强,其选择性遵循磷酸氢盐 > 乙酸酯 > 磷酸二氢盐 > 氯化物的顺序。本研究的结果表明,通过在硫脲结合位点的硫原子上引入适当的荧光团,可以很容易地从非荧光硫脲基受体中获得各种类型的荧光 PET 传感器。