ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 10, pp. 1773!1775. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + V.Yu. Gusev, E.V. Baigacheva, A.V. Radushev, T.D. Batueva, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80,
No. 10, pp. 1744!1746.
Extraction of Copper(II) with N, N-Diethylbenzohydrazide
V. Yu. Gusev, E. V. Baigacheva, A. V. Radushev, and T. D. Batueva
Institute of Technical Chemistry, Ural Division, Russian Academy of Sciences, Perm, Russia
Received September 4, 2006; in final form, December 2006
Abstract-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.
The exists a rather wide assortment of compounds
that can be used for extraction of copper(II) from
various media . However, the extractive agents
employed in industry have a number of disadvantages
that limit their applicability and stimulate a search for
new, more effective reagents. A promising class of
compounds for Cu(II) extraction is constituted by
hydrazides suggested for recovery of CuII) from acid
solutions . There have been no reports devoted to
Cu(II) extraction with N, N-dialkyl derivatives of
hydrazides. Meanwhile, introduction of two alkyl
radicals into the hydrazide group can markedly change
the extractive properties of the compounds obtained.
This study is concerned with Cu(II) extraction with
N,N-diethylbenzohydrazide (DEBH), PhCONHN(Et)
DEBH was synthesized as follows. Benzohydrazide
[13.6 g (0.1 mol)] was dissolved in 100 ml of iso-
propanol, 19 ml (0.25 mol) of ethyl bromide was
added, and a solution of 11.2 (0.2 mol) of KOH in
80 ml of isopropanol was introduced dropwise.
The reaction mixture was heated to neutral reaction
(233 h), filtered, and evaporated. To the residue was
added 50 mol of chloroform and the mixture was
filtered and evaporated. The residue was recrystallized
from a 2 : 1 mixture of hexane and n-xylene. Yield
11.2 g (58%); mp = 121.53123.0oC; R
(m-xylene : BuOH = 2 : 1). IR spectrum, n (cm
1572 (amide II); 1639, 1652 (amide I); 3195 (N3H).
H NMR spectrum, d (ppm; J, Hz): 1.09 (t, 6H, Me,
J = 6.9), 2.81 (q, 4H, CH
, J = 6.9), 6.60 (s, 1H, NH),
7.337.5 (m, 3H, Ph), 7.69 (d, 2H, Ph, J = 7.2).
IR spectra were recorded on a Bruker JFS 66/S
Fourier spectrometer in Vaseline oil, and
spectra on a MERCURY plus 300 spectrometer
(300 MHz) in CDCl
, with HMDS as internal stan-
dard. The pH values were measured with an I-160 M
ion-meter with glass and silver chloride electrodes.
UV spectra and the optical densities were measured
with an SF-26 spectrophotometer. SILUFOL plates
served as the chromatographic material. CuSO
, and K
of analytically pure and
chemically pure grades were used. The content of
elements in standard solutions and in the aqueous
phase was determined using the following methods:
Co(II), Ni(II), and Cu(II) by complexonometry ;
small amounts of copper(II), by the extractive-pho-
tometric technique with sodium diethyldithiocarba-
mate ; and Cr(VI), photometrically with diphenyl-
The solubility of the reagent, found gravimetrical-
ly, is 10.5 g l
in m-xylene and 1.6 g l
Figure 1 shows UV spectra of DEBH solutions in
various media. It can be seen that, depending on pH,
the reagent exists in different forms. The acid3base
Fig. 1. UV spectra of DEBH solutions in various media.
(D) Optical density and (l) wavelength. l = 1 cm,
O : EtOH = 10 : 1, c
= 4.9 0 10
M. (1) pH 0.85,
(2) pH 4.82, and (3) 7.3 M NaOH.