9-Aryl-9-xanthenols: a convenient platform for the design of fluorimetric and colorimetric pH indicators
作者:Emmanuel E. Nekongo、Pritha Bagchi、Christoph J. Fahrni、Vladimir V. Popik
DOI:10.1039/c2ob26715b
日期:——
In aqueous and alcohol solutions, colorless and non-fluorescent derivatives of 9-aryl-9H-xanthen-9-ol equilibrate with brightly colored and fluorescent 9-arylxanthylium cations, thus offering a convenient platform for the design of dual-mode indicators for emission and absorption-based pH measurements. The position of the prototropic equilibrium depends only on the hydronium ion concentration and is not affected by general acids or other ions. Furthermore, the equilibrium equivalence point can be readily adjusted by introducing substituents in the xanthenol core. As dehydroxylation of 3,6-dialkoxy-9-(o-tolyl)-9-xanthenol occurs at pH = 6.5, indicators of this type are well suited for biological applications as illustrated by in vitro cell culture studies with NIH 3T3 cells.
在水溶液和酒精溶液中,9-芳基-9H-氧杂蒽-9-醇的无色、无荧光衍生物与鲜艳、有荧光的 9-芳基氧杂蒽阳离子发生平衡,从而为设计基于发射和吸收的 pH 值测量双模式指示剂提供了一个便捷的平台。原电池平衡点的位置只取决于氢离子的浓度,不受一般酸或其他离子的影响。此外,还可以通过在香酚核心中引入取代基来调节平衡等效点。由于 3,6-二烷氧基-9-(邻甲苯基)-9-香酚的脱羟基反应发生在 pH = 6.5 时,因此这种类型的指示剂非常适合生物应用,用 NIH 3T3 细胞进行的体外细胞培养研究就说明了这一点。