Reactions of ferrocene with phthalonitrile on the surface of oxide powders

Article abstract of DOI:10.1134/S1070363206040268

The reaction of ferrocene with phthalonitrile at 200°C in a vacuum in the absence of solvents forms crystals of the monoclinic phthalocyanine β phase and ferrocene polymerization products. The use of oxide powders (SiO ₂, V₂O₅) as a surface for the reaction of ferrocene with phthalonitrile makes it possible to obtain iron phthalocyanines. The samples of pure compounds and deposited phthalocyanine complexes were analyzed by electronic absorption and IR spectroscopy, and X-ray diffraction. Pleiades Publishing, Inc., 2006.

Full text of DOI:10.1134/S1070363206040268

ISSN 1070-3632, Russian Journal of General Chemistry, 2006, Vol. 76, No. 4, pp. 649 653.
Original Russian Text O.N. Suvorova, D. Verle, N.L. Bazyakina, V.V. Kutyreva, S.G. Makarov, E.A. Shchupak, 2006, published in Zhurnal Obshchei
Khimii, 2006, Vol. 76, No. 4, pp. 684 688.
Pleiades Publishing, Inc., 2006.
Reactions of Ferrocene with Phthalonitrile
on the Surface of Oxide Powders
O. N. Suvorova*, D. Verle**, N. L. Bazyakina*,
V. V. Kutyreva*, S. G. Makarov*, and E. A. Shchupak*
*
Razuvaev Institute of Organometallic Chemistry,
Russian Academy of Sciences, ul. Tropinina 49, Nizhny Novgorod, 603950 Russia
e-mail: suvor@iomc.ras.ru
*
* Institute of Organic and Macromolecular Chemistry, University of Bremen, Germany
Received July 8, 2005
Abstract The reaction of ferrocene with phthalonitrile at 200 C in a vacuum in the absence of solvents
forms crystals of the monoclinic phthalocyanine phase and ferrocene polymerization products. The use of
oxide powders (SiO , V O ) as a surface for the reaction of ferrocene with phthalonitrile makes it possible to
2
2 5
obtain iron phthalocyanines. The samples of pure compounds and deposited phthalocyanine complexes
were analyzed by electronic absorption and IR spectroscopy, and X-ray diffraction.
DOI: 10.1134/S1070363206040268
Catalysts based on phthalocyanine metal com-
plexes (PcM) fixed on oxide supports are presently
widely used in as catalysts in chemical and petro-
chemical processes [1, 2]. Phthalocyanine coatings on
the surface of oxide powders can be obtained by
various procedures, both using ready phthalocyanines
and by directly synthesizing phthalocyanine com-
plexes from aromatic nitriles and inorganic and
organic metal compounds [3].
metal ligand bonds. However, there have been scarce
data on the use of solid-phase reactions of metallo-
cenes for synthesizing phthalocyanine metal com-
plexes. Zakharov et al. [7] have studied the reaction
of ferrocene adsorbed in the cavities of Y zeolite with
phthalonitrile vapors in a vacuum at 100 150 C,
yielding iron(II) phthalocyanine.
Ferrocene derivatives can be used as orientants in
the processes of directed heterogeneous growth of
PcM films [8]. We showed previously [9] that reac-
tions of oxidized forms of ferrocene and its deriva-
tives with aromatic nitriles, carried out in solutions,
To obtain phthalocyanine systems immediately on
the surface of inorganic oxide supports, we used reac-
tions of organometallic compounds with aromatic
nitriles. Previously we obtained low-molecular and
polymeric metal phthalocyanines from metal car-
bonyls and aromatic nitriles by reactions on the sur-
face of SiO and TiO powders and studied the cata-
5
1
+
provide
[( -CpFe- -Cp)(PN) ] An
molecular
2
complexes. Phthalonitrile (PN) and tetracyanobenzene
readily form polyindoline systems under the action of
ferrocenyllithium in tetrahydrofuran at room tempera-
ture [9].
2
2
lytic and photocatalytic activity of these systems in
sulfide oxidation reactions [4].
In this work we present the results of studying re-
actions of ferrocene with phthalonitrile without sup-
ports and in the adsorption layers on the surface of
SiO powders of various dispersity and on V O
The interest in reactions of organometallic com-
pounds occurring either in the solid phase or on the
surface of solid supports is defined by the unique
properties of these systems, which allows their use
both for preparative synthesis of new organic metal
complexes and for preparing organometallic com-
pound inorganic support composite materials [5].
2
2
5
microcrystals.
The reaction between solid ferrocene and phthalo-
nitrile, mixed in a 1:4 ratio, occurs in evacuated
ampules at 210 C in the melt of the components. The
main reaction product formed quantitatively is phthalo-
The mobility of the (C H ) rings in solid (C H )
n x
n
n
n
MLy complexes is known to be almost the same as
their mobility in solutions [5, 6], and the high adsorp-
tion capacity of these compounds on the surface of
oxide supports should result in certain activation of
cyanine (PcH ). According to the X-ray phase analysis,
2
it was a pure monoclinic phase. The electronic ab-
sorption spectrum of the resulting macrocycle (Fig. 1)
corresponds to published data [8]. Therefore, in this
649

6
50
SUVOROVA et al.
Adsorption of ferrocene on SiO is known to give
0
.35
2
+
+
A
the cationic forms Fe and (FeH) [10]. The cationic
forms of ferrocene do not tend to form stable com-
plexes with electron-donor ligands of any kind. Re-
actions with such ligands result in destruction of
ferrocene and cleavage of Cp ligands. Coordination
of nitrile molecules on metal yields an iron-containing
phthalocyanine ring. If the concentrations of the
reagents are low (estimated so that to cover the oxide
surface with a monomolecular layer of phthalocya-
nine), iron phthalocyanine is mainly formed. At in-
creased reagent concentrations on the surface of SiO2
of the same dispersity, a mixture of iron phthalocya-
nine and metal-free phthalocyanine.
0
0
.30
.25
0
.20
.15
0
0
0
.10
.05
0
3
00 400 500 600 700 800 900
nm
,
Fig. 1. Electronic absorption spectrum of PcH in
2
o-dichlorobenzene.
Of special interest for obtaining catalytic systems
is V O , which is due to its intrinsically high catalytic
2
5
activity in oxidation organic compounds, high redox
potential, and high electronic and ionic conductivities.
In our work we used microcrystalline vanadium(V)
oxide of orthorhombic modification with the lattice
3
2
parameters a 11.50(2), b 3.56(3), and c 4.36(8)
,
particle size 200 700 nm, and specific surface area
2
1
3
.7 m g .
The layered structure of V O favors its facile
2
5
intercalation with organic molecules, thus determining
high reactivity of vanadium oxide in the reactions
with organic complex-forming compounds [11]. The
reaction of vanadium(V)oxide with phthalonitrile at
1
300 C gives vanadyl phthalocyanine (PcVO) in high
yield.
1
600 1400 1200 1000 800 600 400
By DTA we determined the temperature ranges for
the reactions of ferrocene with V O , of phthalonitrile
1
,
cm
2
5
with V O , and of ferrocene with phthalonitrile de-
2
5
Fig. 2. IR spectra of (1) ferrocene, (2) vanadium(V)
oxide, and (3) V O (FcH) intercalation complex.
posited on vanadium(V) oxide. In the FcH/V O
2
5
2
5
0.15
system at 240 C, ferrocene is intercalated into the
layered structure of vanadium(V) oxide to give a
reaction, ferrocene plays the role of both a template
agent and a hydrogen donor, forming a polyferro-
cenylene film on the walls of the reactor, and needle-
shape crystals of phthalocyanine grow on this very
film.
V O (FcH) complex. The IR spectra of the starting
2
5
0.15
compounds and resulting intercalation complex are
given in Fig. 2. The Mossbauer spectrum of V O
2
5
(
FcH)0.15 (Fig. 3) shows that ferrocene is oxidized
upon intercalation to give the ferricenium ion. This is
evidenced by a substantial decrease of the quadrupole
splitting (from 2.35 to 0.66 mm s ); therewith, the
By studying the reaction of ferrocene with phthalo-
nitrile, adsorbed on the surface of silicon oxide of
1
2
1
various dispersity (380 and 160 m g ), we found that
the degree of support dispersity, reaction temperature,
and the way the reagents have been deposited on the
surface of silicon oxide do not essentially affect the
direction of the reaction resulting in formation of iron
phthalocyanine and free phthalocyanine. The ratio of
the reaction products is mostly affected by the ratio
of the concentrations of the starting reagents to
the surface area of the support.
isotope shift changes only slightly, which results from
charge transfer from ferrocene to vanadium oxide
lattice and formation of the ferricenium cation. Along
with this, the spectral data also point to appearance of
a noticeable amount of bivalent iron. It seems to be
iron oxide FeO resulting from ferrocene oxidation.
In the Debye powder pattern of the intercalation
complex lattice, additional bands appear, and a slight
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 4 2006

REACTIONS OF FERROCENE WITH PHTHALONITRILE
651
change in interplanar spacings is observed, which
suggests that the symmetry of V O crystals is
(
a)
100
2
5
lowered to the monoclinic syngony. Furthermore,
bands of FeO were identified. The ferricenium cation
and iron oxide impart magnetic properties to the
resulting material. Recently Okino and Matsubayashi
9
6
9
2
[12] reported the preparation of intercalation com-
plexes of metallocenes in the lattice of hydrated
vanadium(V) oxide.
88
84
According to DTA, the reaction of phthalonitrile
with vanadium(V) oxide occurs in the range 270
(
b)
3
00 C to give vanadyl phthalocyanine. The reaction
1
00
99
of ferrocene with phthalonitrile deposited on vana-
dium(V) oxide at a temperature lower than the fer-
rocene intercalation temperature (210 C) yields iron
phthalocyanine (PcFe) and PcVO. We could perform
qualitative analysis of the mixture of phthalocyanines
by means of electronic spectroscopy, using different
solvents and relying on their different dissolving
ability toward the two phthalocyanines (Fig. 4).
Tetrahydrofuran dissolves PcVO but does not dissolve
iron phthalocyanine. When PcVO is removed from
the surface of vanadium(V) oxide with THF, the elec-
tronic spectrum of the treated sample, recorded in
DMF, contains a single PcFe band. The reaction at
9
8
4
2
0
2
4
6
1
V, mm s
Fig. 3. Mossbauer spectrum of (a) ferrocene and
2
70 C results in exclusive formation of PcVO, i.e.
(
b) V O (FcH)
intercalation complex.
2
5
0.15
intercalated ferrocene does not react with phthalo-
nitrile. In this case, we have a composite material
containing the ferricenium cation and vanadyl phthalo-
cyanine in the oxide matrix.
0
.6
A
0.5
.4
1
2
0
EXPERIMENTAL
0
0
.3
.2
The electronic absorption spectra in DMF, THF,
and o-dichlorobenzene were measured on a Perkin
Elmer Lambda-2 spectrometer. The IR spectra in KBr
were recorded on a Perkin Elmer SP-1000 instrument.
0.1
0
400
500
600
700
800
nm
,
The Mossbauer spectra were measured on an MS-
2
2-01 spectrometer in the constant accelerations mode
Fig. 4. Electronic absorption spectra of (1) PcFe and
(2) PcVO in DMF.
5
7
with a Co source in a Cr matrix. The calibration was
carried out against sodium nitroprusside (quadrupole
1
splitting 1.7034 mm s ). The X-ray phase analysis
The reactions were performed in evacuated am-
pules at the FcH-to-PN ratio of 1:4. Reagents were
deposited on powders successively from the vapor
phase and by simply mixing the ingredients. The
ampules were heated for 35 h. The initial reaction
temperature was determined by DTA. The reagent
ratios required for obtaining a monomolecular phthalo-
cyanine layer on the oxide surface were estimated
from the specific surface area of the oxide. Taking
into account that the effective surface area of a
was carried out on a DRON-3M diffractometer (CuK
radiation, graphite monochromator).
The specific surface areas of oxides were measured
on a Beta Scasaam-4200 (29.9% N ) instrument.
2
Ferrocene, phthalonitrile (Fluka) and V O (ortho-
2
5
2
1
rhombic, specific surface area 3.7 m g ) (Riendel-
de-Haen) were used as received. Silicon dioxide
2
1
(
quartz, specific surface area 160 and 380 m g ),
2
purchased from Aldrich, was first heated for 4 h under
vacuum at 350 C.
phthalocyanine molecule is 1.7 nm , we found that to
form a monomolecular phthalocyanine layer on the
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 4 2006

652
SUVOROVA et al.
surface of the support requires 0.1 mol of phthalo-
cyanine per 100 m of the surface. Provided the yield
is quantitative, this corresponds to 0.1 mmol of iron in
ferrocene and 0.4 mmol of phthalonitrile.
In another experiment, the same mixture was
heated at 270 C. The reaction product was washed in
a Soxhlet apparatus with acetone. Electronic spectrum
of the extracted compound, max, nm: 346, 686
2
(
DMF); 343, 685 (THF).
Reaction of ferrocene with phthalonitrile.
a. Without support. Solid ferrocene, 0.56 g, and
1
Reaction of phthalonitrile with V O . Phthalo-
2
5
.54 g of phthalonitrile were thoroughly mixed, and
nitrile, 0.917 g, and 5 g of V O were thoroughly
mixed. The mixture was placed into an ampule. The
ampule was evacuated, sealed, and heated for 35 h at
2
5
the mixture was placed into an ampule. The ampule
2
was evacuated (10 mm Hg), sealed, and heated for
3
5 h at 210 C. The resulting material was washed in
3
00 C. The reaction product was washed in a Soxhlet
a Soxhlet apparatus first with acetone and then with
THF. A violet substance, 1.53 g (90%), was obtained.
Electronic absorption spectrum (o-chlorobenzene),
apparatus first with acetone and then with THF. Elec-
tronic spectrum of the extracted compound, max, nm:
3
46, 686 (DMF); 343, 685 (THF).
1
max, nm: 330, 660, 688. IR spectrum, , cm : 717,
7
30, 751 (CH); 1006 (NH); 1306, 1318, 1338, 1386
Reaction of ferrocene with V O . Ferrocene,
2
5
(C=C); 3290 (NH).
0
.333 g, and 5 g of V O were thoroughly mixed. The
2
5
mixture was placed into an ampule. The ampule was
evacuated, sealed, and heated for 35 h at 240 C. The
reaction product was washed with hexane. IR spec-
2
1
b. On SiO2 (160 m g ). Ferrocene, 0.14 g,
phthalonitrile, 0.41 g, and 5 g of SiO were mixed.
2
Two sample preparation procedures were used. The
first involved mechanical mixing of the starting
materials under argon. The second involved deposi-
tion of ferrocene and phthalonitrile on the support
from the vapor phase. The samples were loaded into
ampules, and the ampules were evacuated, sealed, and
heated for 35 h at 210 C. The resulting material was
washed in a Soxhlet apparatus first with acetone and
then with THF. Electronic absorption spectrum of the
1
trum, , cm : 1026 (VO); 1001 (CH; 978, 844, 719
(
VO); 540, 412 (FeCp). Found, %: C 8.50; H 0.67.
V O (FcH)0.15. Calculated, %: C 8.57; H 0.71.
2
5
ACKNOWLEDGMENTS
The work was financially supported by the Russian
Foundation for Basic Research (project no. 03-03-
2944-a) and by the President of the Russian Federa-
3
extracted compound (DMF):
660 nm. When the
max
tion (project no. NSh-1652.2003.3).
concentrations of ferrocene and phthalonitrile were
increased by a factor of 10, the electronic absorption
spectrum in o-chlorobenzene showed the following
bands, max, nm: 330, 660, 688.
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1
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2 5
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