ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2017, Vol. 62, No. 10, pp. 1379–1383. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © A.I. Dement’ev, S.N. Rodyakina, D.B. Kayumova, N.N. Kamkin, N.G. Yaryshev, A.S. Alikhanyan, 2017, published in Zhurnal Neorganicheskoi Khimii,
2017, Vol. 62, No. 10, pp. 1380–1385.
PHYSICAL METHODS
OF INVESTIGATION
Synthesis and Thermodynamics of Lead(II), Manganese(II),
and Cobalt(II) Pivalate Complexes
A. I. Dement’eva, †, S. N. Rodyakinaa, b, D. B. Kayumovab,
N. N. Kamkina, N. G. Yarysheva, and A. S. Alikhanyanb, *
aInstitute of Biology and Chemistry, Moscow State Pedagogical University, Moscow, 119435 Russia
bKurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia
*e-mail: alikhan@igic.ras.ru
Received October 27, 2016
Abstract⎯Manganese and cobalt oxopivalates and lead pivalate have been synthesized, mass spectral and
thermogravimetric analysis have been performed. Sublimation enthalpies of cobalt and manganese oxopiva-
lates have been determined for the first time, while the sublimation enthalpy of lead pivalate has been found
to agree well with literature data. Low sublimation enthalpy, high volatility, and monomolecular composition
of gas phase allow one to use these complexes as precursors for preparing oxide films and materials by
MOCVD method.
DOI: 10.1134/S0036023617100060
late complexes of lead(II), manganese(II), and
cobalt(II).
The synthesis of all the compounds was accom-
plished by the reaction of freshly deposited hydroxides
and pivalic acid in aqueous medium in molar ratio 1 : 2.
Volatile metal complexes, in particular metal piva-
lates showing a unique set of physicochemical proper-
ties, are promising for preparing functional materials.
One of these properties is the ability to transfer into gas
phase at relatively low temperatures, which provides a
possibility to use these compounds as precursors in
chemical vapor deposition (CVD) method. This
method, depending on deposition conditions, allows
preparation of oxide, metallic, carbide films and coat-
ings with interesting electrical, optical, magnetic, and
catalytic properties. For example, thin films based on
lead and manganese oxides are employed in the pro-
duction of catalysts [1], gas sensors [2], magnetic col-
loidal suspensions [3], while metallic cobalt layers are
widely used as electrically conducting, radio absorb-
ing, anticorrosive, and protecting coatings [4, 5].
Therefore, it is necessary to perform systematic study
of thermodynamic characteristics of volatile metal
complexes; this information makes it possible to con-
trol the thickness of prepared films and synthesize
films of prescribed composition. There are many dif-
ferent structures of carboxylate complexes, therefore
not only composition but also the structure of volatile
complexes used in CVD method is important for the
synthesis of functional film materials. Therefore, the
search for useful precursors is an urgent task for the
preparation of functional materials. This work deals
with the synthesis, structure analysis, and determina-
tion of certain thermodynamic characteristics of piva-
M(OH)2 + HPiv → pivalate complexes.
(1)
Reaction course was judged by the disappearance
of transparent pieces of pivalic acid, water formation,
and quick solidification of resultant gel-like phase.
Thus obtained products were washed with large amount
of water and dried under vacuum (p < 1 × 10–4 Pa) at
ambient temperature.
The prepared compounds were identified by mass
spectral (MS) analysis on a Thermo Scientific DSQII
commercial analytical quadrupole mass-spectrometer
equipped with a Thermo Scientific DIP direct sample
inlet system. As was shown in the works [6, 7], micro
crucible of direct inlet system can be considered as an
analog of Knudsen effusion cell. Therefore, investiga-
tion procedure for vaporization processes is the same
as in the classical mass spectral experiment. Such
experimental procedure allows one to employ widely
distributed commercial devices instead of special mass
spectral equipment.
The synthesized compounds were placed into
direct inlet micro crucible. Temperature programming
was as follows: a sample was kept at 323 K for 3 min,
next the temperature was increased at minimal possi-
ble rate 10 K/min up to 673 K and maintained con-
stant for 5 min. Temperature was measured with a
Pt/Pt–Rh thermocouple and monitored using digital
†
Deceased.
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