T. D. Batueva

Extraction of copper(II) with N,N-diethylbenzohydrazide

Extraction of Cu(II) with N,N-diethylbenzohydrazide and the effect of ammonium salts on this process were studied. The composition and structure of the complex being extracted was analyzed.

Extraction and complexing of copper(II) with benzoic acid N,N-dihexylhydrazide

The solubility and acid-base properties of benzoic acid N,N-dihexylhydrazide (BDHH) were studied. The extraction of copper(II), cobalt(II), nickel(II), zinc(II), iron(III), platinum(II), platinum(IV), chromium(III), chromium(VI), palladium(II), and molybdenum(VI) with this reagent was studied. It was shown that BDHH most efficiently extracts copper(II) from ammonia solutions and chromium(VI) from sulfuric acid solutions. In the extraction of copper(II), complexes with the [Cu(II)]: [BDHH] = 1: 1 and 1: 2 stoichiometries were found to form. The structure of the 1: 2 complex was suggested proceeding from its IR spectra. A copper(II) extraction isotherm was plotted.

Rhenium(VII) extraction with 2-ethylhexanoic acid N,N-dialkylhydrazides from acidic solutions

Rhenium(VII) extraction with 2-ethylhexanoic acid N′,N′-dialkylhydrazides in kerosene from acidic media was studied. Optimal extraction conditions were established depending on H2SO4, HCl and extractant concentrations and the composition of extracted complexes. A mechanism of perrhenate ion extraction and back-extraction with ammonium solutions was proposed.

Extraction and complexation of Cu(II) with undecanoic acid N,N -diethylhydrazide

A new reagent, undecanoic acid N,N-diethylhydrazide, was synthesized, and its pKa1 was determined. The reagent recovers Cu(II) to 99–100% from solutions whose acidity ranges from pH 6 to 1 M NH3. Copper(II) is extracted in the form of a neutral complex of the composition Cu(II):reagent = 1:2. The reagent is incorporated in the complex in the deprotonated form. An equation for the extraction of Cu(II) from ammonia solutions was suggested. The extraction isotherm was constructred. Ammonium salts, when present in solution, considerably decrease the degree of copper extraction. The reagent is less efficient extractant of copper than N,N-diethylbenzhydrazide.

Physical and chemical properties of N′,N′-aliphatic acid dioctylhydrazides and their complexing with copper(II) ions

Some physical and chemical properties of aliphatic acid N′N′-dioctylhydrazides[RC(O)NHN(C8H17)2] (DOHs) were studied in comparison to 2-ethylhexanoic acid N′N′-dialkylhydrazides, namely, solubility, acid-base properties, entrainment with an aqueous phase, and partition factors depending on the medium and the acyl radical length. The pH ranges of maximal extraction of copper(II) complexes by DOHs to kerosene and the effect of ammonium salts on copper(II) extraction were determined. The compositions of extracted complexes were determined (Cu(II): DOH = 1: 1 and 1: 2); the extraction constant Kextr was calculated for the CuL2 complex with butyric acid N′N′-dioctylhydrazide.

Copper(II) complexation and extraction with 2-ethylhexanoic acid N′,N′-dialkylhydrazides

Abstract2-Ethylhexanoic acid N′,N′-dibutylhydrazide (DBH) and N′,N′-diheptylhydrazide (DHH) were synthesized. The existence regions of copper (II), zinc(II), nickel(II), and cobalt(II) complexes formed upon extraction with DBH in kerosene were studied. The neutral complex ML2 extracted over a wide pH range (from pH ∼ 6 to

Extraction of vanadium(V) by N′,N′-dialkylhydrazides of carboxylic acids from acidic solutions

c_{NH_3 }

Recovery of tungsten(VI) and molybdenum(VI) with N′,N′-dialkylhydrazides of aliphatic carboxylic acids from acid solutions

∼ 4 mol/L) is formed only by copper(II), while zinc(II), nickel(II), and cobalt(II) react with DBH to yield precipitates that float at pH 7–9, 9–10.5, and 9.5–11, respectively. On the basis of IR spectra, elemental analysis, and properties, a structure was suggested for the CuL2 complex with DBH. The DBH and DHH complexes with copper(II) are readily stripped with H2SO4 and H2SO4 + CuSO4 solutions. The capacity of a 1.5 mol/L DHH in kerosene with respect to copper(II) is 26 g/L.