Application of Crowned Spirobenzopyran Derivatives as Colorimetric Reagents

点击翻译按钮获取中文摘要

Spirobenzopyrane derivatives bearing monoazacrown ether or diazacrown ether units were synthesized, and in the liquid - liquid extraction their extraction behavior of alkali metal ions was determined by spectrophotometry under the dark and the photo-irradiation conditions. Under the dark conditions, crowned spirobenzopyran derivatives bearing monoaza -12-crown-4, -15-crown-5, and -18-crown-6 units extracted selectively lithium, lithium, and sodium ions, respectively. The metal ion extraction abilities of the crowned spirobenzopyan derivatives were increased under UV-irradiation conditions compared with those of under the dark conditions, and vice versa under the visible light irradiation conditions. Diaza-12-crown-4 derivative bearing two spirobenzopyran units extracted lithium and calcium ions selectively in the liquid - liquid extraction of alkali and alkaline earth metal ions, respectively. The extraction ability for lithium ion was increased remarkably by UV-irradiation. The extraction colorimetry of lithium ion was studied by the flow injection analysis (FIA) using monoaza-12-crown-4 and diaza-12-crown-4 derivatives bearing spirobenzopyran unit(s) under the dark and UV-irradiation conditions. Diaza-12-crown-4 derivative showed the higher selectivity for lithium ion, and the enhancement of the extraction ability was observed by UV-irradiation.