Oxidation of indium with triphenylbismuth in polar solvents

Article abstract of DOI:10.1007/s11176-005-0506-5

The formal-kinetics relationships and products of the reaction of triphenylbismuth with indium in polar solvents were determined. The probable reaction scheme is discussed.

Full text of DOI:10.1007/s11176-005-0506-5

Russian Journal of General Chemistry, Vol. 75, No. 11, 2005, pp. 1763 1765. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 11, 2005,
pp. 1846 1848.
Original Russian Text Copyright
2005 by Maslennikov, Malysheva, Spirina, Klement’eva.
Oxidation of Indium with Triphenylbismuth in Polar Solvents
S. V. Maslennikov, E. V. Malysheva, I. V. Spirina, and S. V. Klement’eva
Research Institute of Chemistry, Lobachevsky Nizhni Novgorod State University, Nizhni Novgorod, Russia
Received September 23, 2004
Abstract The formal-kinetics relationships and products of the reaction of triphenylbismuth with indium
in polar solvents were determined. The probable reaction scheme is discussed.
Numerous experimental data on redox metal inter-
change have been accumulated [1 4]. When elucidat-
ing the mechanism of such reactions, it is necessary to
take into account the adsorption of the oxidant and
ligand (polar solvent) molecules on the metal surface,
ionization potential of the metal and its electron work
function, electron affinity of the oxidant molecule,
and donor acceptor properties of the solvent [4, 5].
Marshall and Pollard [2] believe that, in oxidation of
mercury with compounds PhnM (M = Zn, Cd, Sn, Pb,
Bi), adsorption of the organometallic compound on
the mercury surface is followed by replacement of the
metal atom with the mercury atom by the SE mechan-
ism. The extent of the reaction increases at more
coplanar arrangement of the phenyl groups in the or-
ganometallic molecule and decreases with an increase
in the C M bond energy. According to [3], the possi-
bility of occurrence and the mechanism of metal inter-
change are governed by the sum of the ionization
potential and electron affinity (I + E), and also by the
enthalpy of atomization of the compact metal. The
extent and rate of the reaction are proportional to the
difference between the sums I + E for the participating
metals M and M :
accordance with Bochkarev’s conclusions [3], are the
most promising as sources of aryl groups in metal
interchange. The difference in I + E between Bi
(13.24 eV) and In (5.79 eV) is very large. Therefore,
according to [3], the reaction of Ph3Bi with In should
be fast and proceed to high conversions.
The dependence of the rate of indium oxidation
with triphenylbismuth on the solvent donor number
passes through a maximum (Fig. 1) in the case of
DMSO. At 373 K and a fourfold excess of the metal
powder relative to the oxidant in DMSO (COx 0.1 M),
the reaction requires no less than 14 h for the comple-
tion. After removal of the unchanged indium and pre-
cipitated bismuth (yield 0.97 mol per mole of the ini-
tial oxidant), the solvent was removed under reduced
pressure. The colorless oxygen- and moisture-sensitive
residue was recrystallized from chloroform. Character-
istics of the product: mp 207.9 C; IR spectrum,
,
1
cm : 1597, 1490, 1068, 672. Found In, %: 33.5.
C18H15In. Calculated In, %: 33.2 (published data: mp
1
208 C [7]; IR spectrum, , cm : 1595, 1490, 1070,
673 [8]). Thus, the reaction product can be identified
as triphenylindium (C6H5)3In; its yield was 0.96 mol
per mole of triphenylbismuth:
RnM + M = RnM + M.
(1)
(C6H5)3Bi + In
(C6H5)3In + Bi.
(2)
The approach suggested in [3] for estimating the
extent and mechanism of redox metal interchange
does not allow quantitative determination of the reac-
tivity of organometallic compounds used as oxidants
in the metal interchange and the solvent effect on the
process. In solving these problems, it is appropriate
to use the kinetic method with which it is possible to
determine not only the activation parameters of such
reactions, but also the character of adsorption of the
reactants on the metal surface.
The dependence of the rate of indium oxidation
with triphenylbismuth on the oxidant concentration in
DMSO is shown in Fig. 2. A maximum in the kinetic
curves indicates that the reactants are adsorbed on
active centers of similar nature on the metal surface
[9]. The apparent activation energy of the process in
1
the range 383 403 K is 70 kJ mol , which is typical
of kinetically controlled reactions [10]. To calculate
the equilibrium constants of adsorption of the react-
ants on the indium surface, it is necessary to elucidate,
following the recommendations of [9], the dependence
of the reaction rate on the ligand concentration. How-
ever, experimental determination of this dependence
was unfeasible, because in the presence of commonly
As investigation object we chose the reaction of
triphenylbismuth with indium in polar solvents. It is
known [6] that, among all the metals, bismuth has the
largest sum I + E, and hence bismuth derivatives, in
1070-3632/05/7511-1763 2005 Pleiades Publishing, Inc.

1764
MASLENNIKOV et al.
8
1.0
3
2
0.8
0.6
0.4
3
7
2
1
6
1
5
0.2
0
4
2
3
1
9
0
20 40 60 80 100 120 140
0.1
0.2
0.3
C(Ph3Bi), M
1
DN(SbCl5), kJ mol
Fig. 1. Relative rate of indium oxidation with triphen-
ylbismuth vs. solvent donor number: (1) p-xylene,
(2) acetonitrile, (3) ethyl acetate, (4) THF, (5) diglyme,
(6) DMF, (7) dimethylacetamide, (8) DMSO, and
(9) pyridine.
Fig. 2. Rate of indium oxidation with triphenylbismuth
in DMSO as a function of oxidant concentratiuon. T, K:
(1) 383, (2) 393, and (3) 403.
used inert diluents (toluene, p-xylene) [11] the reac-
tion was extremely slow, and addition of n-heptane
caused phase separation. It should be noted that a sim-
ilar pattern was observed in oxidation of indium with
dicobalt octacarbonyl [12] in THF in the presence of
an inert diluent. The possible cause of the reaction
cessation in the presence of an inert diluent (toluene,
p-xylene) is competition of the solvent with the phen-
yl groups of (C6H5)3Bi for the adsorption centers on
the indium surface. For structurally related adsorbates,
their concentration on the solid surface will be deter-
mined by their content in the bulk. In the course of
an experiment, the concentration of an inert diluent
exceeds the oxidant concentration by a factor of 10
100, which may drastically decelerate the reaction.
mean Bi C bond length of 2.24 , and mean CBiC
bond angle of 94 . Such a geometry suggests that the
distance between the bismuth atom and the indium
surface in contact with the p-C atoms of the phenyl
rings (opposite to the Bi atom) should be 2.69 . At
the same time, according to reference data [15], the
sum of the covalent radii of the Bi and In atoms can
be estimated at 2.95 . Hence, this mechanism of the
metal interchange is quite probable provided that the
deformation of the triphenylbismuth molecule upon its
adsorption on the indium surface is not too strong.
EXPERIMENTAL
Indium wire 0.5 mm in diameter was produced
from the 99.998% pure metal [GOST (State Standard)
102-97-75]. Triphenylbismuth was prepared in accord-
ance with the procedure suggested in [16]. Organic
solvents, if necessary, were purified and dried by
standard procedures [17]. The analysis for indium and
bismuth was performed by commonly used procedures
[18]. All manipulations with the compounds prepared
were performed under reduced pressure or under dry
deoxygenated argon. The IR spectra of triphenylindi-
um were recorded on an IKS-29 spectrophotometer
(mulls in mineral oil). The reaction kinetics was moni-
tored by the resistometric method adapted to readily
oxidizable and hydrolyzable compounds [19].
In the initial part of the kinetic curve (Fig. 2), the
reaction rate is proportional to the Ph3Bi concentra-
tion, i.e., the reaction is first-order with respect to the
oxidant. This corresponds to two possible reaction
schemes. In the first case, C6H5In is formed on the
metal surface and then passes into the solution, where
it reacts with an oxidant molecule to form (C6H5)3In.
In this case, the diphenylbismuthyl radical (C6H5)2Bi
arising in the first step should transform, in accord-
ance with [13], into tetraphenyldibismuthine, which,
in turn, should subsequently decompose into triphenyl-
bismuth, diphenyl, and phenylbismuthine (C6H5Bi)x.
However, in this study we detected in the reaction
products neither diphenyl not phenylbismuthine. The
alternative pathway involves transfer of three electrons
from indium metal to the triphenylbismuth molecule
adsorbed on the indium surface, with simultaneous
transfer of three phenyl groups to the indium atom.
According to [14], the triphenylbismuth molecule has
a pyramidal structure with a symmetry close to C3v,
REFERENCES
1. Considine, W.Y. and Wentura, Y.Y., J. Organomet.
Chem., 1965, vol. 3, no. 5, p. 420.
2. Marshall, R.A.G. and Pollard, D.R., J. Organomet.
Chem., 1971, vol. 27, no. 2, p. 149.
3. Bochkarev, M.S., Metalloorganicheskie soedineniya i
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 11 2005

OXIDATION OF INDIUM WITH TRIPHENYLBISMUTH IN POLAR SOLVENTS
1765
radikaly (Organometallic Compounds and Radicals),
11. Maslennikov, S.V., Cand. Sci. (Chem.) Dissertation,
Kabachnik, M.I., Ed., Moscow: Nauka, 1985, p. 200.
Nizhni Novgorod, 1999.
4. Maslennikov, S.V., Spirina, I.V., Malysheva, E.V.,
and Zhdanovich, I.V., Main Group Met. Chem., 2002,
vol. 25, no. 5, p. 289.
12. Maslennikov, S.V., Malysheva, E.V., Spirina, I.V.,
and Artemov, A.N., Zh. Obshch. Khim., 2005, vol. 75,
no. 4, p. 529.
5. Maslennikov, S.V., Spirina, I.V., and Piskunov, A.V.,
13. Wiberg, E. and Modritzer, K., Z. Naturforsch. (b),
Zh. Obshch. Khim., 2001, vol. 71, no. 11, p. 1837.
1957, vol. 12, p. 132.
6. Energiya razryva khimicheskikh svyazei. Potentsialy
ionizatsii i srodstvo k elektronu: Spravochnik (Dis-
sociation Energies of Chemical Bonds. Ionization
Potentials and Electron Affinities: Handbook),
Kondrat’ev, V.N., Ed., Moscow: Nauka, 1979.
7. Nesmeyanov, A.N. and Sokolik, R.A., Metody ele-
mentoorganicheskoi khimii. Bor, alyuminii, gallii,
indii, tallii (Methods of Organometallic Chemistry.
Boron, Aluminum, Gallium, Indium, Thallium),
Moscow: Nauka, 1964.
14. Hewley, D.M. and Ferduson, G., J. Chem. Soc. (A),
1968, no. 9, p. 2059.
15. Nekrasov, B.V., Kurs obshchei khimii (Course of
General Chemistry), Moscow: Goskhimizdat, 1962.
16. Kocheshkov, K.A., Skoldinov, A.P., and Zemlyan-
skii, N.N., Metody elementoorganicheskoi khimii.
Sur’ma, vismut (Methods of Organometallic Che-
mistry. Antimony, Bismuth), Moscow: Nauka, 1976.
17. Gordon, A.J. and Ford, R.A., The Chemist’s Com-
panion. A Handbook of Practical Data, Techniques,
and References, New York: Wiley, 1972.
8. Radionov, A.N., Ruch’eva, N.I., Viktorova, I.M.,
Shitorin, D.N., Sheverdina, N.I., and Kochesh-
kov, K.A., Izv. Akad. Nauk SSSR, Ser. Khim., 1969,
no. 5, p. 1047.
18. Charlot, G., Les methods de la chimie analytique.
Analyse quantitative minerale, Paris: Masson, 1961,
4th ed.
9. Bremer, H. and Wendlandt, K.-P., Heterogene
Katalyse: eine Einfuhrung, Berlin: Akademie, 1978.
10. Benson, S.W., The Foundations of Chemical Kinetics,
19. Zhukov, S.L., Lavrent’ev, I.P., and Nifontova, G.A.,
New York: McGraw-Hill, 1960.
React. Kinet. Catal. Lett., 1977, vol. 7, no. 4, p. 405.
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