Department of Chemistry, Mississippi State University, Hand Lab 1115, Mississippi State, Mississippi 39762, United States.
School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States.
J Org Chem. 2020 Oct 2;85(19):12108-12116. doi: 10.1021/acs.joc.0c01242. Epub 2020 Sep 11.
An effective design strategy with an efficient synthetic route to xanthene-based far-red to near-infrared dyes is reported. The dyes were prepared by the Suzuki cross-coupling of the electron-poor fluorescein ditriflate with the electron-rich boronic acid/ester-functionalized pyrrole () and indole () moieties. Upon treatment with trifluoroacetic acid, the closed nonfluorescent forms of the dyes ( and ) ring-opened to their fluorescent forms ( and ). The absorption maxima were 665 and 704 nm, while the emission maxima were 717 and 719 nm for and , respectively. The closed forms of the dyes were soluble in chloroform and acetonitrile. To test the efficacy of the dyes as probes, a turn-off fluoride ion probe was prepared from , which consisted of a silyl ester receptor. The probe responded strongly to low concentrations of fluoride, carbonate, and acetate ions, weakly to phosphate ions, but not to the other halogens. Moreover, the probe can detect the minimum concentration of F in water.
报道了一种基于呫吨的远红至近红外染料的有效设计策略和高效合成路线。这些染料是通过缺电子的荧光素三氟甲磺酸酯与富电子的硼酸/酯官能化吡咯（）和吲哚（）部分的 Suzuki 交叉偶联制备的。用三氟乙酸处理后，染料的闭环非荧光形式（和）开环形成其荧光形式（和）。吸收最大值分别为 665nm 和 704nm，发射最大值分别为 717nm 和 719nm 对于和，分别。染料的闭环形式在氯仿和乙腈中是可溶的。为了测试染料作为探针的效果，从制备了一种作为关闭型氟离子探针的染料，它由一个硅酯受体组成。探针对低浓度的氟离子、碳酸根离子和醋酸根离子有强烈的响应，对磷酸根离子的响应较弱，但对其他卤素离子没有响应。此外，该探针可以检测水中的最低氟浓度。
