2-Hydroxy-4-Isopropoxy-5-Bromoacetophenone Oxime as an Analytical Reagent for Cu(II)

Abstract

2-Hydroxy-4-isopropoxy-5-bromoacetophenone oxime (HIBAO) was developed as a new analytical reagent for the gravimetric estimation of Cu(II). In pH range 3.5-8.0 the reagent gives a brown coloured precipitate with Cu(II). Spectrophotometric methods revealed that the stoichiometry of the complex is 1 : 2 (metal : ligand). Beer's law is obeyed up to 76.42 ppm of Cu(II). Molar absorptivity and Sandell’s sensitivity at 400 nm were found to be 6.32 × 10² L mol^–1 cm^–1 and 0.108 μg/cm² respectively. The stability constant of Cu(II)-HIBAO complex is found to be 4.25 × 10⁹. Gibb’s free energy change for complex formation reaction was found to be –13.18 kcal/mol. The reagent can be used for the analysis of brass.