1-[(4,6-二甲基-2-嘧啶)偶氮]-2-萘酚的合成及其与钴Ⅱ的显色反应

Synthesis of 1-[(4, 6-Dimethyl-2-pyrimidinyl)azo]-2-naphthol and Its Color Reaction with Cobalt

合成了新显色剂 1 [( 4 ,6 二甲基 2 嘧啶 )偶氮 ] 2 萘酚 (DMPAN) ,并研究了该试剂的性质及其与钴显色反应的条件。结果表明 :试剂的离解常数 pka=7 4,λmax=374 0nm ,在 pH6 2 2的磷酸盐缓冲介质中 ,试剂与钴形成红色 1∶1络合物 ,其最大吸收波长λmax=42 6nm ,络合比Co2 +∶R =1∶1 ,摩尔吸光系数ε=2 66× 1 0 4 ,钴量在 0～ 1 2 μg/mL范围内遵守比尔定律 ,在掩蔽剂作用下 ,可不经分离直接用于含钴样品的分析 ,结果满意。

The synthetic method of a new reagent 1 [(4, 6 dimethyl 2 pyrimidinyl)azo] 2 naphthol(DMPAN)and its color reaction with Co 2+ are reported. The structure of the reagent are determined by elemental analysis, UV spectrometer, IR spectroscopy and HNMR spectroscopy. The reagent reacts with Co 2+ to form a stable red complex(1:1)in the presence of Triton X 100 in pH6 22 phosphate buffer solution, the apparent molar absorptivity is 2.66×10 4L·mol -1 ·cm -1 at λ max =426nm. Beer's law is obeyed in the range of 0-1.2μg/mL. The proposed method has been applied to the spectrophotometric determination of cobalt in vitamin B 12 injection.