Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 5, pp. 892−894.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © M.V. Buzaeva, V.V. Dubrovina, O.A. Davydova, E.S. Klimov, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 5,
Dissolution of Copper in the Presence of ortho-Quinones
with Electron-Acceptor Substituents
M. V. Buzaeva, V. V. Dubrovina, O. A. Davydova, and E. S. Klimov
l’yanovsk State Technical University, Ul’yanovsk, Russia
Received July 13, 2010
Abstract—Dissolution of copper in organic media in the presence of complexons, whose role is played by spatially
hindered ortho-quinones with electron-acceptor substituents and acetylacetone, is considered.
Machine-building and radioelectronic industries
widely use etching solutions based on inorganic salts and
peroxides: iron-chloride, copper-chloride, ammoniac,
and persulfate, to etch copper surfaces and printed-
circuit boards. Wastewater from plants of this kind
contains environmentally hazardous waste substances.
Utilization of spent solutions is economically inefﬁ cient
. Organic reagents are hardly used at all for etching
of copper, which is due to the high ionization potential
of copper. An acceptable way to solve the problem of
dissolution of metals in organic media is by using the
A method is known in which metallic copper is
dissolved in the presence of acetophenoxime and
acetylacetone to give copper(II) acetylacetonate,
benzonitrile, and benzoic acid . There are examples
of oxidative dissolution of copper in organic solvents
containing 3,5-di-tert-butylbenzoquinone-1,2 with
addition of cyclohexyl isocyanide and styrene. In this
case, the ﬁ nal products are bis-benzosemiquinolate
complexes of copper(I) and copper(II) . Among
disadvantages of these methods are the low yield of
copper acetylacetonate and formation of an unmarketable
main product and by-products.
The goal of our study was to examine the possibility
of dissolving metallic copper in organic media in the
presence of spatially hindered ortho-quinones to give
the minimum number of products at the maximum yield
of the target commercial product.
The starting ortho-quinones, 3,5-di-tert-butyl-6-
) and 3,5-di-tert-butyl-
), were produced
by the methods described in . Acetylacetone (AcAc) of
analytically pure grade [GOST (State Standard) 10259–
78) was used. Below are presented ortho-quinones (Q)
and their reduced forms (QH
R(3,5) = –C(CH
(6) = –SCN (Q
); R(3,5) =
(6) = –C(CN)=C(CN)
We monitored the dissolution rates of copper, using
the electron paramagnetic resonance (EPR) method,
by changes in the intensity of the EPR signal from
the paramagnetic ion of copper , measured with
a radiospectrometer from Bruker BioSpin GmbH.
Because measurements of absolute concentrations of
radicals in EPR spectroscopy involves a gross error, we
measured the relative variation of the intensity of the
EPR signal with time in evacuated systems (residual