INORGANIC SYNTHESIS AND INDUSTRIAL
Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 10, pp. 1684−1693.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © A.K. Baev, E.A. Evsei, E.A. Telushchenko, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 10, pp. 1592−1601.
Distribution and Dynamics of Transformation
of Hydrolytic Cationic Forms of Nickel(II)
A. K. Baev, E. A. Evsei, and E. A. Telushchenko
Institute of Solution Chemistry, Ivanovo, Russia
Received October 19, 2010
Abstract—A system Ni
O was examined by dialysis under equilibrium conditions using step constants of
hydrolysis to constructs distribution diagrams of Ni(II) cationic forms in a dependence on a pH value of a solution.
We considered the reaction dynamics of hydrolytic cationic forms of nickel(II) and substantiated schemes of
realized processes with a change in pH.
Sorption and sol gel techniques are widely used for
synthesis of nickel-oxide catalyst. They are applied
to a solution of problems in nanochemistry covering
synthesis and reactivity of particles, formation of
pseudo-colloidal and colloidal particles and ensembles,
and their physicochemical properties. In this regard a
substantiation of a role of particles that differ in size
and charge on proceeding of processes depending on pH
is of particular importance. It enables determination of
conditions for production of surface phase composition
of nickel-oxide samples , modification of nickel
compounds with additives of various electron-donating
ligands for synthesis of highly efﬁ cient catalysts of the
selective action .
A concept earlier developed of hydrolytic
polymerization of metal ions [3 5] and, in particular,
the presence in solution of Ni(II) ions, Ni
[6 8] led to consideration of a mechanism of
the processes and determination of quantitative kinetic
characteristics of hydroxide complex formation [9 20].
In this regard systematization of knowledge is required
on homopolynuclear hydroxo complex formation,
reaction dynamics of cationic forms of complexes of
elements depending on changes in pH of a solution.
The solution of this problem provides accounting of
features of the cationic forms interaction in the hydroxide
technique of synthesis of complex oxide materials, ﬁ lm
nickel-oxide coatings and proceeding to development of
a forecasting system of the conditions of their production.
A purpose of the study is an examination of the
dynamics of transition of the nickel cationic forms to
the homopolynuclear hydroxo complexes and colloidal
precipitates with a change in pH of the system Ni
According to carried out investigations [21 23] in the
solutions of the system Ni
O with a change in
pH of a medium a mononuclear hydroxyl complex NiOH
and polymeric hydroxyl complex Ni
[22, 23]. Several authors in  pointed to the existence
of a dimeric complex Ni
. In [8, 25] an existence
of trimeric hydroxo complexes Ni
in the 3 M NaNO
solution. Determined thermodynamic
parameters of polymeric complexes Ni
[8, 25] with the assumptions were used in
 for calculation of a distribution of aqua complexes,
tetrameric hydroxo complex Ni(OH)
and anionic forms
for 0.1 and 10
M Ni(II) solutions.
Performed approximate calculations showed a complete
transformation of the aqua complexes in 0.1 M Ni(II)
solutions into the tetrameric hydroxo complexes at pH ≈
10, which are transformed then into Ni(OH)
13% content in the solution, and into anionic forms of