2,4-Dihydroxy-5-Bromovalerophenone Oximes as a Gravimetric Reagent for Ni(II) and Cu(II) and Spectrophotometric Study of Complexes

Abstract

2,4-Dihydroxy-5-bromovalerophenone oxime (DHBVO) was developed as a new analytical reagent for the gravimetric estimation of divalent nickel and copper ions. In pH range of 3.0 to 6.0, this reagent gives a buff colored precipitate with Cu²⁺. Job’s method and mole ratio method revealed that the stoichiometry of the complex is 1 : 2, the beer’s law is obeyed up to 38.12 ppm of Cu²⁺. The molar absorptivity at 420 n was found to be 5.31 × 10² L mol^-1 cm^-1. The stability constant of the complex is found to be 1.885 × 10⁹. Ni²⁺ gives light green colored precipitate in pH range 7.0 to 9.0. Using both the above-mentioned methods, it was found that stoichiometry was 1 : 2. The molar absorptivity at 440 nm was found to be 1.79 × 10² L mole^-1 cm^-1. The stability constant of the complex found to be 1.24 × 10⁹. Beer’s law is obeyed upto 35.22 ppm of Ni²⁺. The reagent can be used for the analysis of German silver alloy.