Synthesis of 1-azobenzene-3-(3,5-dibromo-2-pyridyl)-triazene and its colour reaction with cadmium

The synthesis of a new reagent 1 Azobenzene 3 (3,5 dibromo 2 pyridyl) triazene(ABDBPDT) and its colour reaction with cadmium were reported. At pH 10 9, in the presence of Triton X 100, ABDBPDT could form a red complex with Cd(Ⅱ). The maximum absorptions of the reagent and the complex are at 430nm and 530 nm, respectively. The molar absorptivity is 1.75×10 5 L·mol -1 ·cm -1 for the complex. Beer's law was obeyed in the range of 0 μg/25mL～12 μg/25mL for cadmium.