PAN-S 与铜离子反应的分光光度研究

本文用分光光度法研究了PAN-S与铜离子的络合反应,并用以作为滴定剂对铜进行光度滴定.Cu离子与PAN-S在pH≤6时,形成1:1的络合物;在pH≥8时,形成1:2的络合物.从不同pH扫描所得的吸收线,用作图法求得1:1Cu-PAN-S的稳定常数logk_1为14.59.

Spectrophotometric Investigation of the Reaction of Cupric Ions with PAN-S

Here is proposed a method based on the sensitive reaction between PAN-S and cupric ion for the spectrophotometric titration determination of copper. PAN-S forms a 1:1 complex at pH 6 and 2:1 complex at pH 8 with cupric ion as shown by a study of continuous variation method. The abso-rption spectrum of 1:1 Cu-PAN-S chelate at various pH has been studied in aqueous solutions. The molar absorption coefficient and stability constant of the 1:1 chelate formed have been evaluated from the absorbance curves by graphical method.