K. Makhmudov, R. Alieva, S. R. Gadzhieva
May 3, 2008
Citations
0
Influential Citations
30
Citations
Journal
Journal of Analytical Chemistry
Abstract
Abstract1-Ethoxy-2-(2-hydroxy-3-sulfo-5-chlorophenylazo)butane-1,3-dion (L1), 1-ethoxy-2-(2-hydroxy-3,5-disulfophenylazo)butane-1,3-dion (L2), 1-ethoxy-2-(2-hydroxy-4-nitrophenylazo)butane-1,3-dion (L3), and 1-ethoxy-2-(2-hydroxyphenylazo)butane-1,3-dion (L4) were synthesized on the basis of ethyl acetoacetate, and their analytical characteristics were studied. The following dissociation constants of the reagents were determined by potentiometric titration: pK1 = 5.94 ± 0.04 and pK2 = 9.75 ± 0.04 (L1), pK1 = 5.78 ± 0.02 and pK2 = 9.55 ± 0.03 (L2), pK1 = 6.03 ± 0.03 and pK2 = 9.86 ± 0.05 (L3), and pK1 = 6.19 ± 0.05 and pK2 = 9.98 ± 0.06 (L4). The chemical analytical characteristics of copper(II) complexes of L1–L4 were determined by spectrophotometry. It was found that, with an increase in the elecrophilic properties of the substituents introduced into the aromatic ring of the molecule, the sensitivity of the reaction increased; the substituents had no effect on the ratio of Cu : L = 1 : 2. A photometric procedure was developed for determining copper in nickel-based alloys.