1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯的合成及其与铜的显色反应

Synthesis of 1-azobenzene-3-(5-bromo-2-pyridyl)-triazene and its Color Reaction with Copper

报道了新显色剂1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯的合成.在pH11.5的Na2B4O7-NaOH缓冲溶液中,TX-100表面活性剂存在下,1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯与铜发生显色反应,生成3:1的红色配合物.配合物的最大吸收波长位于540nm处,表观摩尔吸光系数为8.

The 1- azobenzene- 3- （5- bromo- 2- pyridyl） -triazene （ABBPDT） as a chromogenic reagent was synthesized and its color reaction with copper has been investigated. In the presence of the surface active agent Triton X - 100 and in the Na2B4O7 - NaOH medium of pH 11.5, ABBPDT forms a red complex with Cu（ IT ）. The apparent molar absorbtivity of the complex is 8.13 × 10^4L·mol^-1·cm^-1 at 540nm（λmax）. The molar ratio of Cu（ Ⅱ ） to ABBPDT is 3 ： 1. Bee＇ s law is well obeyed in the range of 0-7.5μg/25mL for cadmium. This method is applied to determine trace amounts of cadmium in aluminum alloy sample and trace amounts of copper in tea and rice with satisfactory results.