Peculiarities of thermal decomposition of inorganic and organometallic compounds of GeIV and GeII. Thermolysis of (acac) 2GeX2 (X = Cl, N3) and (CO) 5MGeCl2(thf) (M = Cr, Mo, W)

Article abstract of DOI:10.1023/A:1026023814429

Thermal decomposition of the complexes (acac)₂Ge(N ₃)₂ (1), (acac)₂GeCl₂ (2), and (CO)₅M=GeCl₂(THF) (M = Cr (3), Mo (4), W (5)) was studied by differential scanning calorimetry a

Full text of DOI:10.1023/A:1026023814429

Russian Chemical Bulletin, International Edition, Vol. 52, No. 8, pp. 1681—1687, August, 2003
1681
Peculiarities of thermal decomposition of inorganic and organometallic
IV
II
compounds of Ge and Ge . Thermolysis of (acac) GeX (X = Cl, N )
2
2
3
and (CO) MGeCl (thf) (M = Cr, Mo, W)
5
2
Zh. V. Dobrokhotova,aꢀ P. S. Koroteev, A. V. Saushev, G. G. Aleksandrov,
a
b
a
a
a
c
V. M. Novotortsev, S. E. Nefedov, and M. P. Egorov
aN. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
3
1 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (095) 954 1279. Eꢀmail: zhdobro@yandex.ru
b
Department of Chemistry, M. V. Lomonosov Moscow State University,
Leninskie Gory, 119899 Moscow, Russian Federation.
c
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
7 Leninsky Prosp., 119991 Moscow, Russian Federation.
4
Thermal decomposition of the complexes (acac) Ge(N ) (1), (acac) GeCl2 (2), and
2
3 2
2
(
CO) M=GeCl (THF) (M = Cr (3), Mo (4), W (5)) was studied by differential scanning
5 2
calorimetry and thermogravimetry. The phase compositions of the products of thermolysis of
compounds 1—3 and 5 were determined by Xꢀray phase analysis. Possible schemes of thermal
decomposition of these compounds were proposed. The heat capacities of complexes 3—5 were
studied in the temperature range 113—313 K. The structures of complexes 1 and 5 were
established by Xꢀray diffraction analysis.
Key words: thermal decomposition, heat capacity, complexes of GeII and GeIV, synthesis,
structure.
Elucidation of peculiar features of thermal decompoꢀ
sition of coordination and organometallic compounds is a
topical research avenue in modern inorganic chemistry.
This allows one not only to reveal subtle specific thermal
effects due to intramolecular rearrangements upon abꢀ
sorption of excess energy but also to obtain, after all, such
inorganic compounds that possess unique physicochemiꢀ
cal properties but in some cases cannot be synthesized
using traditional experimental techniques.1
XꢀRay diffraction study of complex 1 (Fig. 1) revealed
that the germanium atom is in a distorted octahedral enꢀ
vironment of four oxygen atoms (Ge—O(1) 1.891(9) Å,
Ge—O(2) 1.935(9) Å, Ge—O(3) 1.889(9) Å, Ge—O(4)
1.926(9) Å), two acac ligands, and nitrogen atoms of
two azide fragments (Ge—N(1) 1.942(12) Å, Ge—N(4)
1.926(11) Å) arranged in cisꢀposition relative to each other
(in the axial and equatorial positions, respectively).
The presence of diazide groups in complex 1 allowed
one to expect generation of carbene analogs upon UV
irradiation, which is known for diazideꢀcontaining comꢀ
pounds of the Group IVB elements. However, photolysis
resulted in a poorly soluble germaniumꢀcontaining polyꢀ
mer rather than the expected germanium(II) bis(acetylꢀ
acetonate).
—3
In this work we report on the synthesis, structure,
thermal decomposition, and determination of the heat
II
IV
capacities of some complexes containing Ge and Ge
atoms. Such compounds are of great interest as promising
precursors of novel materials with unusual physicochemiꢀ
cal (including catalytic) properties.
Yet another method for generating carbene analogs is
thermal decomposition of the corresponding diorganylꢀ
silicon (germanium, tin) diazides. In this work we estabꢀ
Results and Discussion
5
4
Earlier, we have found that refluxing of (acac) GeCl
lished that thermal decomposition of complex 1 begins at
80±2 °C and involves two distinct stages. In the first stage,
compound 1 melts with decomposition in the temperaꢀ
ture range 90—150 °C (Fig. 2). In the second stage, the
decomposition continues, being accompanied by a large
exothermic effect. At temperatures above 400 °C, no
weight loss of the decomposition product was observed.
2
2
with NaN3 (2 mol) in acetonitrile for 5 h reꢀ
sults in bis(acetylacetonato)germanium(IV) diazide,
(
acac) Ge(N ) (1), in 82% yield. Complex 1 was isolated
2 3 2
as colorless crystals well soluble in organic solvents and
readily hydrolyzable in solution. Single crystals of comꢀ
plex 1 were prepared by recrystallization from toluene.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1593—1599, August, 2003.
066ꢀ5285/03/5208ꢀ1681 $25.00 © 2003 Plenum Publishing Corporation
1

1
682
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 8, August, 2003
Dobrokhotova et al.
Gaseous products of the decomposition of complex 1
were not analyzed. Nevertheless, based on the relative
weight of the solid residue (35.9%), the phase composiꢀ
tion of the decomposition product (see Table 1), correꢀ
spondence between the intensities of the characteristic
reflections of the crystalline phases in the Xꢀray diffracꢀ
tion pattern and their weight content in the decomposiꢀ
tion product (GeO : Ge N : Ge = 6 : 4 : 1), and the
C(2)
N(3)
C(3)
C(1)
O(1)
C(4)
2
3
—8
4
N(2)
6
results obtained earlier,
we can propose a possible
C(5)
scheme of thermal decomposition of the compound unꢀ
der study (Eq. (1)).
O(2)
N(1)
N(4)
(
aсас) Ge(N )
0.5 GeO + 0.125 Ge +
2
Ge(1)
2
3 2
O(4)
C(6)
+
+
0.125 Ge N + 3 CO↑ + 2.5 N ↑ + 2 CH ↑ +
3 4 2 4
C H ↑ + 3 C.
(1)
2
6
C(7)
O(3)
A comparison of the data on thermal decomposition
of complex 1 containing azide fragments, which can
N(5)
N(6)
readily generate N , with analogous data for the structurꢀ
2
ally similar complex (acac) GeCl (2) containing rather
C(9)
2
2
C(8)
strongly bound apical chlorine atoms showed that the
latter is thermally stable to 200 °C under the experimental
conditions. Above this temperature, complex 2 melts with
decomposition (see Fig. 2, b), the intense weight loss in
the temperature range 206—290 °C being accompanied
by substantial absorption of energy. Subsequent heating
of the sample to 500 °C occurs without pronounced therꢀ
mal effects and is accompanied by gradual decrease in
weight. No weight loss of the decomposition products was
observed above 470 °C. The total weight loss of the sample
of complex 2 in the temperature range 25—500 °C is
75.6±2.0%. Thermal decomposition of compound 2 reꢀ
sults in a darkꢀgrey substance containing metallic germaꢀ
nium (tetragonal and cubic modifications) and germaꢀ
C(10)
Fig. 1. Molecular structure of complex 1.
The total relative weight loss due to thermal decomposiꢀ
tion is 64.1±2.0%. Thermolysis of compound 1 results in
a greyꢀbrown substance containing GeO , Ge, and Ge N
2
3
4
(
determined by Xꢀray phase analysis, see Table 1).
Table 1. Phase analysis of decomposition products of compound 1
Table 2. Phase analysis of decomposition products of compound 2
Decomposiꢀ
tion product
GeO2
Ge N4
Ge*
3
Decomposiꢀ
tion product
GeO2
Ge*
Ge**
d/Å I (%)
d/Å I (%) d/Å I (%) d/Å I (%)
d/Å I (%)
d/Å I (%) d/Å I (%) d/Å I (%)
4
3
3
2
2
2
2
2
2
2
2
2
2
.036 60
.432 40
.154 25
.892 50
.820 40
.673 15
.639 40
.490 30
.356 10
.320 20
.145 10
.078 15
.000 15
4.070 100
3.477
2.815
60
80
4.064 80
3.341 60
3.208 30
2.907 30
2.625 30
2.483 20
2.357 15
2.209 30
1.985 30
1.569 20
4.070 100
3.160
2.883
40
80
3.266 100
3.160
2.883
40
80
2.690 100
2.471 20
2.690 100
2.629 100
2.473
2.495
2.350
2.228
1.957
1.538
1.442
40
20
60
60
40
10
2.471
20
2.495
2.350
2.228
2.127
40
20
60
40
7
2.000
50
1.825
1.543
1.456
60
10
15
2.008
50
1.446
5
1.957
60
*
Tetragonal modification.
*
Tetragonal modification.
** Cubic modification.

II
IV
Thermal decomposition of Ge and Ge complexes Russ.Chem.Bull., Int.Ed., Vol. 52, No. 8, August, 2003
1683
m/mg
Q/mW
6
4
a
c
5
4
3
2
0
2
–
2
00
400
T/°C
200
400
T/°C
m/mg
Q/mW
b
d
6
4
3
.0
.5
.0
0
.5
–1.0
–
2.5
–
4.0
2
00
400
T/°C
200
400
T/°C
Fig. 2. Weight losses (a, b) and heat flows (c, d) of complexes 1 (a, c) and 2 (b, d) plotted vs. temperature.
nium dioxide (determined by Xꢀray phase analysis, see
In this connection it was of interest to study thermolyꢀ
sis of such organometallic complexes that simultaneously
Table 2). The GeO : Ge ratio estimated from the correꢀ
2
spondence between the intensities of the characteristic
reflections of the crystalline phases and their weight conꢀ
tent in the decomposition product is 1.5 : 1.
Using the approach employed for compound 1, we
can propose the following scheme of thermal decomposiꢀ
tion of complex 2:
O(1)
O(4)
C(1)
C(4)
O(3)
Cl(1)
(
aсас) GeCl2
0.25 GeO + 0.25 Ge +
2
2
C(3)
W(1)
+
+
0.5 GeCl ↑ + 2 CH ↑ + C H ↑ + 3.5 CO↑ +
4 4 2 6
Cl(2)
C(6)
Ge(1)
2.5 C.
(2)
C(5)
O(5)
C(2)
Thus, the results obtained for the two structurally simiꢀ
lar complexes studied in this work show that the complex
containing azide groups instead of chlorine atoms beꢀ
comes much less thermally stable. Compounds 1 and 2
melt with decomposition at rather low temperatures, which
suggests their use as molecular precursors in preparation
of inorganic materials with prescribed stoichiometric comꢀ
positions.
O(6)
O(2)
C(9)
C(7)
C(8)
Fig. 3. Molecular structure of complex 5.

1
684
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 8, August, 2003
Dobrokhotova et al.
II
contain (i) Ge atoms and atoms of different transition
metals and (ii) ligands capable of leaving the coordination
sphere of the metal with ease on heating. The following
compounds, (CO) MGeCl (thf) (M = Cr (3), Mo (4),
a result, the Ge atom is in the distorted tetrahedral enviꢀ
ronment.
Thermogravimetric studies revealed that thermal deꢀ
composition of compounds 3—5 is a stepwise process.
The initial decomposition temperature increases from the
chromiumꢀcontaining complex 3 to the tungstenꢀconꢀ
taining complex 5 (70±3, 74±3, and 80±3 °C, respecꢀ
tively, see Fig. 4). Melting of the compounds begins nearly
simultaneously with decomposition. The weight loss by
the time of completion of the corresponding endothermic
effect (melting was confirmed by visual observations) was
at most 3% for all the three compounds. This allows the
energy absorbed to be treated as equal to the heat of
5
2
W (5)), were chosen as containing the rather labile THF
molecules and carbonyl groups. Complexes 3—5 were
synthesized following known procedures.9 The strucꢀ
ture of complex 5 was established by Xꢀray diffraction
,10
analysis. In molecule 5 (Fig. 3), the W(CO) moiety is
5
directly bound to the germanium atom (2.5335(13) Å)
coordinated by two chlorine atoms (Ge(1)—Cl(1)
2
.192(3) Å, Ge(1)—Cl(2) 2.192(4) Å) and by the oxygen
atom of the THF molecule (Ge(1)—O(6) 1.948(8) Å). As
Q/mW
m/mg
5
3
2
.0
.5
.0
0
1
2
3
a
d
–
–
–
1
00
200
T/°C
100
200
T/°C
Q/mW
m/mg
1
0
b
e
4
.0
–
1
2
3
3.0
–
–
2
.0
1
00
200
T/°C
100
200
T/°C
Q/mW
1
.5
m/mg
c
f
3.0
2.5
2.0
1.5
0
–
–
1.5
3.0
1
00
200
T/°C
100
200
T/°C
Fig. 4. Heat flows (a—c) and weight losses (d—f ) of compounds 3 (a, d), 4 (b, e), and 5 (c, f ) plotted vs. temperature.

II
IV
Thermal decomposition of Ge and Ge complexes Russ.Chem.Bull., Int.Ed., Vol. 52, No. 8, August, 2003
1685
melting. Both the temperature and the melting heat of
the compounds increase from the Crꢀcontaining to
the Wꢀcontaining compound (tmelt = 80.5± 1.0 (3),
Table 3. Phase analysis of the composition of decomposition
products of compound 3
Decomposition product
Cr Ge
Ge
I (%)
8
2
7.5±1.0 (4), 109.6±1.0 (5); ∆meltH = 21603±40 (3),
5555±60 (4), 34036±45 ꢁ mol (5)). Comparison of the
3
–
1
d/Å
I (%)
d/Å
I (%)
d/Å
calculated content of THF in compounds 3—5 (17.6 (3),
5.9 (4), 13.3% (5)) with the weight loss in the first
stage of decomposition (17.0± 1.0 (3), 16.2± 1.0 (4),
3.3±1.0% (5)) suggests that the first stage of thermal
decomposition of all the three compounds involves elimiꢀ
nation of the THF molecule. Under the experimental
conditions, the final THF loss temperature decreases
from the Crꢀcontaining to the Wꢀcontaining compound
3
2
2
1
1
1
1
.256
20
40
100
15
90
10
5
3.263
2.307
2.063
8
50
100
3.266
100
1
.312
.069
.998
.880
.695
.405
1
2.000
60
1.884
100
30
1.706
1.414
1.298
40
10
15
1.292
1.226
5
20
(
t1 = 140±2 (3), 130±2 (4), and 120±2 °C (5)).
1.233
The DSC curves presented in Fig. 4 show that subseꢀ
quent decomposition of the Crꢀcontaining complex 3 is
significantly different from that of the Moꢀ and Wꢀconꢀ
taining compounds. This is likely due to the fact that
thermal destruction at temperatures above the final THF
loss temperature corresponding to completion of the first
stage is primarily due to elimination of the CO ligands.
Under gradual decarbonylation of the complexes, formaꢀ
tion of the additional M—Ge and M—M bonds becomes
possible, the bonds involving the 3dꢀmetals being much
weaker than those involving the 4dꢀ and 5dꢀmetals posꢀ
sessing more extended orbitals. In addition, formation of
the multiple bonds, which is typical of molybdenum and
tungsten,11 cannot be ruled out. This seems to be the
most probable reason for compensation of the energy exꢀ
penditure for decarbonylation of complexes 4 and 5 owꢀ
ing to the formation of new bonds. Most likely, these
processes are also responsible for the experimentally obꢀ
served energy release during the decomposition of 4 and 5
in contrast to the decomposition of complex 3 (only endoꢀ
therm is observed in that case). The temperature correꢀ
sponding to complete decomposition under the experiꢀ
mental conditions decreases from the Crꢀcontaining comꢀ
pound to the Wꢀcontaining analog (260±3 (3), 250±3 (4),
and 240±3 °C (5)).
Table 4. Phase analysis of the composition of decomposition
products of compound 5
Decomposition product
W Ge3
Ge*
I (%)
5
d/Å
I (%)
d/Å
I (%)
d/Å
3
3
2
2
2
1
.339
10
15
40
80
50
10
7
3.440
10
.235
.486
.310
.131
.980
3.266
100
2.460
2.370
2.190
40
100
80
2.000
1.706
60
40
1.711
*
Cubic modification.
of the melting temperature, which is rather high (e.g., for
1
2
Cr Ge intermetallide t
= 1530±30 °C).
3
melt
Taking into account the results obtained and the total
weight loss during thermolysis of the complexes studied
in this work (79.5±1.5% for 3 and 69.5±1.5% for 5), we
can propose the following schemes of thermal decompoꢀ
sition of complexes 3 and 5 (the composition of the gas
phase was not studied):
The results obtained show that the thermal stabilities
of complexes 3—5 are insignificantly reduced from the
Crꢀcontaining to the Wꢀcontaining compound. Similarly
to compounds 1 and 2, complexes 3—5 have rather low
melting points and decomposition temperatures. This also
suggests a possibility of using them as molecular precurꢀ
sors of inorganic materials with prescribed stoichiometric
compositions.
(CO) CrGeCl (thf)
0.33 Cr Ge + 0.17 Ge +
3
5
2
+
0.5 GeCl ↑ + 5 CO↑ + C H O↑,
(3)
4
4 8
(
CO) WGeCl (thf)
0.14 W Ge + 0.08 Ge +
5 3
5
2
+ 0.5 GeCl4↑ + 3.2 CO↑ + C4H8O↑ +
0.3 W(CO) ↑.
+
(4)
6
Indeed, our study of the phase compositions of solid
decomposition products of complexes 3 and 5 by Xꢀray
phase analysis (Tables 3 and 4) revealed the presence of
the Cr Ge (for 3) and W Ge (for 5) phases. It should be
Note that metal carbonyl appears in Eq. (4) in conꢀ
trast to Eq. (3). This is due to the fact that significant
decomposition of Cr(CO) occurs at 90 °C, whereas deꢀ
3
5
3
6
noted that traditional synthetic routes to these compounds
involve melt synthesis followed by prolonged annealing to
obtain homogeneous samples or longꢀterm solidꢀphase
synthesis at an optimum temperature equal to two thirds
composition of W(CO) begins at temperatures above
170 °C.
The magnetic behavior of the decomposition products
of complex 5 (Fig. 5) is indicative of a ferromagnetic
6
1
3,14

1
686
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 8, August, 2003
Dobrokhotova et al.
χg–1•106
Table 5. Temperature dependences of the heat capacities of
compounds 3—5
2
1
1
0
.0
1
T/K
C /ꢁ K– mol–1
p
WGe
.5
.0
.5
3
4
5
1
1
1
1
1
1
1
1
13
18
23
28
33
38
43
48
170.9
175.8
180.6
186.2
191.4
196.2
201.1
206.3
212.0
216.8
220.9
226.5
230.1
238.5
245.2
252.7
259.0
265.7
271.1
277.3
283.6
289.0
294.4
299.7
305.2
307.5
175.5
182.0
187.8
193.5
199.6
203.4
208.3
214.3
218.6
224.1
228.7
233.9
237.2
245.3
252.5
259.1
266.2
273.0
279.1
284.4
290.0
296.2
300.8
306.0
310.5
312.8
177.9
184.2
190.2
195.7
202.5
207.2
213.3
218.4
223.0
228.0
233.1
238.0
241.9
249.7
256.8
264.0
271.1
277.5
284.0
289.4
294.8
301.0
305.9
315.3
316.1
318.2
0
5
0
100
150
200
250
T/K
Fig. 5. Inverse magnetic susceptibility of the decomposition prodꢀ
uct of complex 5 plotted as function of temperature.
153
158
1
1
1
1
1
63
68
73
83
93
character of the interaction between paramagnetic cenꢀ
ters. The nature of these centers is still to be clarified.
Obtaining inorganic materials from metal complexes
can also be predicted and described based on the thermoꢀ
dynamic analysis of decomposition processes. However,
correct thermodynamic calculations require knowledge
of the basic thermodynamic characteristics associated with
the formation of compounds.
To determine the enthalpy of formation, we studied
the decomposition of compound 5 in the dynamic (temꢀ
perature range 130—250 °C) and isothermic (at 230 °C)
regimes. The thermal effects obtained were found to be in
203
213
2
2
2
2
2
2
2
2
23
33
43
53
63
73
83
93
dyn
–1
reasonable agreement (∆ H
= –298±10 ꢁ g and
= –320.0±4.0 ꢁ g , respectively).
The heat capacities of complexes 3—5 were deterꢀ
298
r
iso
–1
∆r
H
mined by differential scanning calorimetry in the temꢀ
perature range 113—300 K (Table 5). The calculated
carry out a stepwise DSC study of thermal decomposition, the
temperature range was divided into several intervals. The numꢀ
ber and extension of these temperature intervals were deterꢀ
mined after the overall pattern of changes in the weight and
energy during decomposition was obtained. This experimental
strategy allowed the determination of the weight loss in each
temperature interval and comparison of the results of the DSC
and TG measurements (reasonable agreement between them
served as confirmation of reliability of the results obtained). The
accuracy of determination of the features and thermal effects in
the thermograms was ±1 deg and ±0.5%, respectively. Heat
capacity measurements were carried out using the DSCꢀ25 modꢀ
ule (differential calorimeter capable of scanning the jacket temꢀ
perature and dedicated to quantitative measurements of thermal
effects). The base line stability of the calorimeter was ±50 µW
and the calibration coefficient was automatically maintained at
a constant level over a broad temperature range (–150—600 °C)
and was independent of the sample weight (up to a weight of
100 mg), and the noise level was less than 5 µW. The heat
capacities were measured in the temperature interval 113—300 K
at a sample heating rate of 2 deg min– . This temperature range
was divided into four intervals chosen in such a way that they be
overlapped by at least 40 °C. Five to seven series of measureꢀ
ments with different samples were carried out for each sample.
The heat capacity at a given temperature was determined as the
value averaged over 10 to 12 measurements. This procedure
absolute entropies are 324± 7 (3), 330± 10 (4), and
37±8 ꢁ K–1 mol (5).
–1
3
Thus, our study of thermal decomposition of
the complexes (acac) GeX2 (X = Cl, N ) and
2
3
(
CO) MGeCl (thf) (M = Cr, Mo, W) allowed the deterꢀ
5 2
mination of their initial and final thermal decomposition
temperatures and the phase composition of the solid deꢀ
composition products. Possible schemes of thermal deꢀ
composition were proposed.
Experimental
Compounds 1, 2, and 3—5 8—9 were synthesized followꢀ
4
10
ing known procedures.
Thermal decomposition of compounds 1—5 was studied by
differential scanning calorimetry (DSC) and thermogravimetry
1
(
TG) on a Mettler TAꢀ3000 thermal analyzer (DSCꢀ20 and
TGꢀ50 modules, respectively). Samples were heated in a dry
argon atmosphere at a constant rate of 5 deg min–1. Seven DSC
and six TG analyses were performed for each compound. The
weight loss during thermal decomposition was measured immeꢀ
diately on the TGꢀ50 module with an accuracy of ±2•10– g. To
6

II
IV
Thermal decomposition of Ge and Ge complexes Russ.Chem.Bull., Int.Ed., Vol. 52, No. 8, August, 2003
1687
provided a relative error of determination of 2 to 3%. To evaluꢀ
ate a possible systematic error of measurements, the heat caꢀ
pacities of some reference compounds were measured periodiꢀ
cally. For instance, the heat capacity of corundum differed from
the corresponding values reported by the U.S. National Bureau
of Standards by ±1—2%.
3. A. A. Pasynskii, Zh. V. Dobrokhotova, N. I. Semenova,
Yu. V. Torubaev, and V. M. Novotortsev, Izv. Akad. Nauk,
Ser. Khim., 2003, 896 [Russ. Chem. Bull., Int. Ed., 2003,
52, 944].
4. P. S. Koroteev, M. P. Egorov, O. M. Nefedov, G. G.
Aleksandrov, S. E. Nefedov, and I. L. Eremenko, Izv. Akad.
Nauk, Ser. Khim., 2000, 1825 [Russ. Chem. Bull., Int. Ed.,
2000, 49, 1800].
5. V. N. Khabashesku, V. Balaji, S. E. Boganov, O. M. Nefedov,
and ꢁ. Michl, J. Am. Chem. Soc., 1994, 116, 320.
6. O. N. Suvorova, V. V. Kutyreva, V. A. Varyukhin, and G. A.
Domrachev, in Stroenie, svoistva i primenenie βꢀdiketonatov
metallov [Metal βꢀDiketonates: Structure, Properties, and Apꢀ
plications], Nauka, Moscow, 1978, 116 (in Russian).
7. N. M. Uvarova, V. B. Polikarpov, O. I. Druzhkov, and T. K.
Postnikov, in βꢀDiketonaty metallov [Metal βꢀDiketonates],
Nauka, Moscow, 1078, 14 (in Russian).
The magnetic properties of the decomposition product
of complex 5 were studied on a Quantum Design SQUID
MPMSꢀ59 magnetometer in the temperature range 20—300 K.
The magnetic susceptibility obeys the Curie—Weiss law,
χ = C/(T – θ), with a Weiss constant, θ, of 55 K. The effective
0.5
magnetic moment was assessed using the formula µeff = (8χ T )
.
c
XꢀRay diffraction studies were carried out at the XꢀRay
Structural Center (A. N. Nesmeyanov Institute of Organoꢀ
element Compounds, Russian Academy of Sciences) on a Bruker
AXS SMART 1000 diffractometer (CCD detector, λMoꢀKα,
graphite monochromator, 110 K, ω scanning technique with an
ω increment of 0.3°, a 30 s exposure per frame, 2θ
= 60°)
8. V. A. Varyukhin, V. Yu. Vodzinskii, G. A. Domrachev, B. I.
Kozyrkin, V. V. Kutyreva, and O. N. Suvorova, v sb. Problemy
khimii i primeneniya βꢀdiketonatov metallov [Problems of
Chemistry and Applications of Metal βꢀDiketonates], Nauka,
Moscow, 1982, 178 (in Russian).
max
standard technique.1
5
For compound 5:
using
a
C H Cl Ge O W ,
M
=
539.49, space group Pbca,
9
8
2
1
6
1
a = 6.9214(7) Å, b = 20.791(2) Å, c = 10.4313(10) Å,
3
β = 93.135(2)°, V = 1498.9(2) Å (110 K), Z = 4, number of
measured reflections is 9046, number of independent reflections
9. P. ꢁutzi and W. Steiner, Chem. Ber., 1976, 109, 3473.
10. ꢁ. T. Morgan and H. D. K. Drew, J. Chem. Soc., 1924,
125, 1261.
2
–3
–1
with F > 2σ(I ) is 4004, ρ
= 2.391 g cm , µ = 10.045 cm ,
calc
R = 0.0692, and wR = 0.1550.
1
2
1
1. F. A. Cotton and R. A. Walton, Multiple Bonds between
Metal Atoms, ꢁ. Willey and Sons, New York, 1982.
This work was carried out with the financial support of
the Ministry of Industry, Science, and Technologies of
the Russian Federation (GK 41.002.11.1402), the Rusꢀ
sian Foundation for Basic Research (Project Nos. 02ꢀ03ꢀ
1
2. R. P. Elliott, Constitution of Binary Alloys, First Supplement,
McGraw—Hill Book Co., New York, St. Louis—San Franꢀ
cisco—Toronto—London—Sydney, 1962.
3
3041, 02ꢀ03ꢀ33075, and 03ꢀ03ꢀ06480), and the Basic
13. A. K. Baev and V. V. Dem´yanchuk, Obshchaya i prikladnaya
khimiya [General and Applied Chemistry], Minsk, Vysshaya
shkola, 1970, Issue 2, p. 178 (in Russian).
Research Program of the Division of Chemistry and Maꢀ
terials Science, Russian Academy of Sciences.
1
4. A. K. Baev, Dokl. Akad. Nauk BSSR [Dokl. Byelorussian
Acad. Sci.], 1970, 14, 134 (in Russian).
References
1
5. SMART (control) and SAINT (integration) Software, Verꢀ
sion 5.0, Bruker AXS Inc., Madison (WI), 1997.
1
2
. V. G. Syrkin, CVDꢀmetod. Khimicheskoe parofaznoe
osazhdenie [The Chemical Vapor Deposition Method], Nauka,
Moscow, 2000, 406 pp. (in Russian).
. S. V. Larionov and S. M. Zemskova, Ross. Khim. Zh., 1996,
Received January 13, 2003;
in revised form May 26, 2003
4
0, 171 [Mendeleev Chem. J., 1996, 40 (Engl. Transl.)].