zinc(II) with lawsone, juglone and naphthazarin
نویسندگان
چکیده
The complexation equi li bria of zinc(lI ) wi th 2-hydroxy-IAnaphthoquinone. 5-hydroxyIA-naphthoquinone and 5.8-dihydroxyIA-naphthoquinone have been studied spectrophotometri call y as a function of pH in 50~ (1'/1') ethanol-water medium at 25°C and an ionic strength of 0.1 M NaCI04 . The spectral study of the complexati on reactions has been carried out in solutions contain ing equimolar concentrations or an excess of one component in the pH range of study. The chelation capabilities of these hydrox ynaphthoquinones with zinc(lI) have been examined. The complexation equilibria have been demonstrated and charac terized by analysis of the absorbance versus pH graphs. The composition . molar absorpti vities, equ ilibrium constants and stability constants of zinc(lI ) complexes with these reage nt s have been determined. The fundamental conditions favouring direct spectrophotometric determination of trace amounts of zinc( lI ) using naphthazarin have been investigated.
منابع مشابه
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