1-(5′-溴-2′-吡啶基)-5-(4′-硝基苯基)-3-(2′-呋喃基)甲[月朁]的合成及其与锌显色反应的研究

Syntheses of New Colour Reagent 1-(5'-Bromo-Pyridyl)-5-(4'-Nitro-Phenyl)-3-(2'-Futyl)Formazne and Investigation of Its Colour Reaction with Zinc

甲[月朁]类试剂是有色金属离子的优良显色剂。它们的各种取代衍生物,有许多作为分析试剂已被研究。近年来,为了改善该类试剂的分析性能,在甲[月朁]骨架上接上吡啶、噻唑、眯唑及呋喃等杂环基团,合成了一系列不对称型的杂环甲[月朁]。本文报导5-Br-PNPFF试剂的合成和提纯方法。

The synthesis and purification of a new colour reagent l-(5'-bromo-2'-pyridyl)-5-(4/-nitrophenyl)-3-(2'-Furyl)formazane were investigated.This reagent combines with zinc ions in the presence of nonionic surfactant Twcen-80 in a buffer solution of pH 8.0-10.0 to form a blue-green complex.The complex has an maximum absorption at 688nm with a molar absorptivity of 5.96×10^(4)l·mol^(-1)·cm^(-1).Beer's law is obeyed in the range of 0-4.2μg/10ml for Zn(Ⅱ).The method has been applied to the spectrophotometric determination of micro-amount zinc in ores,with good results.