Syntheses, molecular structures, and thermal decomposition of cyclopentadienyldicarbonylmanganese chalcogenide derivatives

Article abstract of DOI:10.1023/B:RUCB.0000019888.02470.3e

Transmetallation of the dichalcogenide complexes [CpMn(CO) ₂]₂(μ-X₂) (X = S or Se) with M(CO) ₅(thf) (M = Cr or W) afforded new heterometallic complexes CpMn(CO)₂(μ-Se₂)Cr(CO)₅,

Full text of DOI:10.1023/B:RUCB.0000019888.02470.3e

Russian Chemical Bulletin, International Edition, Vol. 52, No. 12, pp. 2689—2700, December, 2003
2689
Syntheses, molecular structures, and thermal decomposition
of cyclopentadienyldicarbonylmanganese chalcogenide derivatives*
A. A. Pasynskii,ꢀ V. N. Grigoriev, Yu. V. Torubaev, A. I. Blokhin,
S. S. Shapovalov, Zh. V. Dobrokhotova, and V. M. Novotortsev
N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation
Fax: (095) 954 1279. Eꢀmail: aapas@rambler.ru
Transmetallation of the dichalcogenide complexes [CpMn(CO)2]2(µꢀX2) (X = S or Se)
with M(CO)5(thf) (M = Cr or W) afforded new heterometallic complexes CpMn(CO)2(µꢀ
Se2)Cr(CO)5, CpMn(CO)2(µꢀSe2)[Cr(CO)5]2, CpMn(CO)2(µꢀX2)[W(CO)5]2 (X = S or Se),
and CpMn(CO)2(µꢀSe2)[Cr(CO)5][W(CO)5]. According to the Xꢀray diffraction data, their
molecular structures contain the cyclic MnX2 fragments coordinated by one or two M(CO)5
groups via the X atoms. Study of thermal decomposition of the manganese complexes with
different Mn : M : X ratios (M = Cr, W; X = S, Se, Te) by differential scanning calorimetry
(DSC) and thermogravimetry demonstrated that this process took place at rather low temperaꢀ
tures (100—400 °C) and was accompanied by complete elimination of the CO groups followed
by elimination of the Cp groups. At any metal to chalcogen ratio, the resulting inorganic
chalcogenides contained no impurities of metal oxides and carbides.
Key words: synthesis, Xꢀray diffraction analysis, thermal decomposition, cyclopentadienyl
complexes, metal carbonyls, metal chalcogenides, manganese, chromium, tungsten.
Scheme 1
The stepꢀbyꢀstep buildingꢀup of a cluster core using
monoꢀ and binuclear dichalcogenide complexes as ligands
for other metal complexes has wide application in the
cluster design of heterometallic chalcogenide clusters. In
particular, the reactions of the binuclear complexes
[(CO)3Fe]2(µꢀX2) (X = S, Se, or Te) with Mo(CO)5(thf)
or Mo(CO)3(MeCN)3 were used for modeling the active
site of the MoFeS cofactor of nitrogenase.1
The binuclear complexes [CpMn(CO)2]2(µꢀX2)
(X = S (1) or Se (2)) were first synthesized by the reacꢀ
tions of photochemically generated CpMn(CO)2(thf) with
COS or COSe, respectively.2 Recently, these complexes
were synthesized using a new method (Scheme 1) through
the anionic carbene complex CpMn(CO)2C(Ph)(O)–
(paramagnetic complexes CpMn(CO)2XC(=O)Ph were
generated as intermediates; the molecular structure of the
complex with X = S was established by Xꢀray diffraction
analysis3).
In molecules 1 and 2, the X—X bond was readily
cleaved by reduction with sodium borohydride in ethanol
or with sodium in tetrahydrofuran. The further reactions
with iodomethane afforded new CpMn(CO)2XMe2 or
[CpMn(CO)2]2XMe2 (X = S or Se) complexes.3 We exꢀ
pected that, by analogy with the known reactions of
[(CO)3Fe]2(µꢀX2),4 the M(CO)5 fragments (M = Cr or W)
would be inserted into the X—X bond of molecules 1 and 2.
Results and Discussion
The reaction of complex 2 with Cr(CO)5(thf) unexꢀ
pectedly gave rise to the monoꢀ and dichromium transꢀ
metallation products as darkꢀlilacꢀcolored crystals of
[CpMn(CO)2](µꢀSe2)[Cr(CO)5] (3) and darkꢀgreen crysꢀ
tals of ([CpMn(CO)2](µꢀSe2)[Cr(CO)5]2 (4), respectively
(Scheme 2).
Each step of this reaction is reversible. The synthesis
of complex 3 from 4 in THF in the presence of CO proved
to be a more convenient procedure compared to the diꢀ
* Materials were presented at the Mark Vol´pin Memorial Inꢀ
ternational Symposium "Modern Trends in Organometallic and
Catalytic Chemistry" dedicated to his 80th anniversary.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2545—2555, December, 2003.
1066ꢀ5285/03/5212ꢀ2689 $25.00 © 2003 Plenum Publishing Corporation

2690
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003
Pasynskii et al.
Scheme 2
Scheme 3
Compound
M
Cr
W
X
S
S
5
6
7
W
Se
It can be assumed that the first step of this reaction
involves coordination of the M(CO)5 fragment to one of
the chalcogen atoms in the Mn—X—X—Mn chain, like
in the known [CpFe(CO)2]2S2W(CO)5 complex5 (W—S,
2.582 Å) (Scheme 5).
rect synthesis of complex 3 from 2. Analogously, darkꢀ
green crystals of the CpMn(CO)2(µꢀS2)[Cr(CO)5]2 comꢀ
plex (5) were prepared starting from complex 1 and
Cr(CO)5(thf).
In the reactions of complexes 1 and 2 with
W(CO)5(thf), only the trinuclear complexes
CpMn(CO)2(µꢀS2)[W(CO)5]2 (6) and CpMn(CO)2(µꢀ
Se2)[W(CO)5]2 (7), respectively, were isolated
(Scheme 3).
C(5)
C(4)
C(3)
C(1)
C(2)
Mn(1)
Finally, the reaction of complex 3 with W(CO)5(thf)
gave a new complex containing three different metals,
viz., [CpMn(CO)2](µꢀSe2)[Cr(CO)5][W(CO)5] (8)
(Scheme 4).
Se(2)
C(6)
O(7)
O(6)
C(7)
Se(1)
Complexes 3—8 were characterized by IR spectrosꢀ
copy, elemental analysis, and/or DSC. The molecular
structures of compounds 3, 4, 6, and 8 were established
by Xꢀray diffraction analysis (Figs. 1—4, Tables 1—3).
All these complexes contain the triangular MnX2 fragꢀ
ment with the single Mn—X and X—X bonds. This fragꢀ
ment is coordinated by one or two M(CO)5 groups via the
substantially shortened M—X bonds (in 3, Se(1)—Cr(1),
2.503(2) Å; in 4, Se—Cr (aver.), 2.497(1) Å; in 6,
W(1)—S(1) (aver.), 2.538(3) Å; in 8, the Cr—Se and
W—Se distances (2.548(1)—2.567(2) Å) are averaged due
to disorder). These groups deviate from the MnX2 plane.
In complexes 4, 6, and 8, these groups are in the anti conꢀ
formation. The CpMn(CO)2 and M(CO)5 groups have a
typical twoꢀlegged pianoꢀstool and tetragonalꢀpyramidal
geometry, respectively.
O(9)
C(9)
O(10)
C(10)
O(8)
Cr(1)
C(11)
O(11)
C(8)
C(12)
O(12)
Fig. 1. Molecular structure of complex 3.

Thermal decomposition of manganese complexes
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003 2691
O(13)
O(6)
O(5)
C(5)
C(3)
C(4)
C(11)
O(15)
C(13)
O(7)
O(16)
C(16)
C(1)
C(2)
C(10)
C(8)
C(12)
W(1)
C(15)
C(5)
Cr(2)
Mn(1)
C(1)
C(17)
O(3)
C(4)
C(9)
C(14)
O(14)
C(7)
O(2)
Se(1)
Se(2)
C(6)
O(4)
O(17)
Mn(1)
C(2)
C(3)
Se(2)
Se(1)
O(1)
C(17)
O(9)
C(7)
O(7)
C(16)
C(14)
C(15)
O(10)
O(12)
C(12)
O(11)
O(12)
Cr(2)
C(6)
C(9)
O(11)
C(11)
C(13)
O(8)
Cr(1)
O(6)
O(9)
O(10)
C(10)
C(8)
Fig. 4. Molecular structure of complex 8.
O(13)
Scheme 4
Fig. 2. Molecular structure of complex 4.
O(13)
C(13)
O(15)
O(17)
C(17)
C(15)
W(2)
C(16)
C(4)
C(5)
O(16)
C(3)
C(14)
O(14)
S(2)
Mn(1)
C(2)
C(1)
S(1)
O(7)
O(12)
C(7)
Scheme 5
C(12)
W(1)
C(6)
O(9)
C(9)
C(10)
O(10)
O(6)
C(11)
C(8)
O(8)
O(11)
Fig. 3. Molecular structure of complex 6.

2692
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003
Pasynskii et al.
Table 1. Crystallographic data for complexes 3, 4, 6, and 8
Parameter
3
4
6
8
Molecular formula
Molecular weight
Color of crystals
Diffractometer
C12H5CrMnO7Se2
526.02
C17H5Cr2MnO12Se2 C17H5MnO12S2W2 C17H5CrMnO12Se2W
718.07
Darkꢀgreen
«Siemens P3»
887.97
Darkꢀgreen
«Siemens P3»
849.92
Darkꢀgreen
«Bruker Smart
1000CDD»
110(2)
P2(1)/n
11.862(8)
13.364(9)
14.077(10)
90
Darkꢀlilac
«Bruker Smart
1000CDD»
11–0(2)
Temperature/K
Space group
a/Å
b/Å
c/Å
α/deg
β/deg
293(2)
P2(1)/n
11.851(2)
13.591(3)
14.317(3)
90
293(2)
P2(1)/n
11.935(2)
13.597(3)
14.420(3)
90
P1
7.020(3)
9.944(5)
11.718(5)
87.381(9)
85.720(9)
78.548(9)
799.1(6)
2
92.85(3)
90
93.55(3)
90
92.98(1)
90
γ/deg
V/Å3
2303.1(8)
4
2335.5(8)
4
2228(3)
4
Z
F(000)
ρ
500
2.186
1376
2.071
1632
2.525
1576
2.533
calc/g cm–3
Radiation,
0.71073
0.71073
0.71073
0.71073
λ(MoꢀKα)/Å
Linear
absorption, µ/mm–1
Absorption correction
6.054
4.687
10.597
9.515
Semiempirically
Psi scan
Psi scan
Semiempirically
based on equivalent
based on equivalent
reflections
reflections
Scan mode
2θmax/deg
Number of measured
ω
56.14
6629
θ/2θ
50.06
3691
θ/2θ
52.02
4741
ω
54.38
26937
reflections
Number of independent
reflections
3720 (Rint = 0.0593) 3432 (Rint = 0.0542) 4518 (Rint = 0.0487) 4857 (Rint = 0.0642)
Number of reflections
with I > 2σ(I )
Number of parameters
R1
2632
2946
3326
2936
208
0.0650
297
0.0639
307
0.0530
308
0.0537
wR2
0.1585
0.1865
0.1321
0.1182
GOF
0.971
1.036/–0.747
0.949
1.226/–1.328
1.115
1.608/–0.823
1.062
2.859/–1.422
(ρmax/eÅ–3)/(ρmin/eÅ–3
)
Such a coordination of the M(CO)5 group by the lone
electron pair at the chalcogen atom decreases the degree
of its involvement in additional binding to the manganese
atom observed in complexes 1 and 2 3 and facilitates disꢀ
proportionation accompanied by the transformation of
two MnII ions into the MnIII ion in complexes 3—8 as
well as into the MnI ion, which is, presumably, removed
as CpMn(CO)2(thf).
verse reaction. In addition to the aboveꢀmentioned
[CpFe(CO)2]2S2W(CO)5 complex,5 these chains have
also been observed earlier in electronically saturated
ditellurides, viz., the dianionic chromium complex
2–
(CO)5Cr—Te—Te—Cr(CO)5
(Te—Te, 2.736 Å;
Cr—Te, 2.743 Å)6 and the uncharged manganese complex
(PЕt3)2(CO)3Mn—Te—Te—Mn(PЕt3)(CO)3 (Te—Te,
2.763 Å; Mn—Te, 2.718 Å).7
Apparently, the energy difference between the chain
and triangular structures is notꢀtooꢀlarge, and the transꢀ
formation of the former into the latter occurs already
upon the replacement of one CpMn(CO)2 group in
diselenide 2 by the isoelectronic Cr(CO)5 group giving
rise to complex 3. However, the triangular structure is
again transformed into the chain structure in the reꢀ
The coordination mode in dirhenium ditelluride
CpRe(CO)2(µ3ꢀTe2)[CpRe(CO)2] (9) is analogous to that
observed in complex 3. The structures of types 4, 6, and 8
were found in dimanganese rhenium ditelluride
Cp*Re(CO)2(µ3ꢀTe2)[CpMn(CO)2]2 (10), which was preꢀ
pared by the reaction of the CpMn(CO)2(thf) complex
with Cp*Re(CO)2H(TeH) and contains the single Te—Te

Thermal decomposition of manganese complexes
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003 2693
Table 2. Bond lengths (d) and bond angles (ω) in the structures
of 3, 4, and 6
Bond
d/Å
Angle
ω/deg
3
3
Se(1)—Se(2)
2.307(1)
Se(2)—Se(1)—Cr(1) 114.16(4)
Se(2)—Se(1)—Mn(1) 62.16(4)
Cr(1)—Se(1)—Mn(1) 123.45(4)
Se(2)—Mn(1)—Se(1) 54.92(3)
Se(1)—Se(2)—Mn(1) 62.92(3)
4
Se(1)—Cr(1) 2.503(2)
Se(1)—Mn(1) 2.510(1)
Mn(1)—Se(2) 2.493(1)
4
Se(1)—Se(2)
2.3160(9) Se(2)—Se(1)—Cr(1) 108.50(4)
Se(1)—Cr(1) 2.506(1)
Se(1)—Mn(1) 2.516(1)
Mn(1)—Se(2) 2.538(1)
Se(2)—Cr(2) 2.488(1)
Se(2)—Se(1)—Mn(1) 63.20(3)
Cr(1)—Se(1)—Mn(1) 121.53(5)
Se(1)—Mn(1)—Se(2) 54.55(3)
Se(1)—Se(2)—Cr(2) 111.85(4)
Se(1)—Se(2)—Mn(1) 62.25(3)
Cr(2)—Se(2)—Mn(1) 122.82(4)
6
6
S(1)—S(2)
W(1)—S(1)
Mn(1)—S(1) 2.389(3)
Mn(1)—S(2) 2.407(3)
2.068(4)
2.538(3)
S(2)—S(1)—W(1)
S(1)—S(2)—W(2)
S(2)—S(1)—Mn(1)
S(1)—S(2)—Mn(1)
S(1)—Mn(1)—S(2)
109.3(1)
113.5(1)
64.9(1)
64.0(1)
51.1(1)
W(2)—S(2)
2.503(3)
analyzed in detail in the monograph.10 Recently, we studꢀ
ied pyrolysis of homoꢀ and heterometallic carbonyl chalꢀ
Mn(1)—S(2)—W(2) 124.4(1)
Mn(1)—S(1)—W(1) 122.75(11)
cogenides11 and established the important dependence of
the composition of inorganic compounds obtained after
pyrolysis on the M : X ratio in the complexes. If this value
is larger than unity, pyrolysis affords impurities of metal
oxides and carbides due to partial decomposition of the
CO groups. If this ratio is equal to or smaller than unity,
the CO ligands are completely removed. It was noted11
that the organic groups and CO were completely elimiꢀ
nated in the presence of the methylcyclopentadienyl
ligands irrespective of the transition metal : chalcoꢀ
gen ratio. This was attributed to the fact that fulvene
C5H4=CH2 was readily detached from the manganese
atom to form the Mn—H bond.
In the present study, we found that thermal decompoꢀ
sition of cyclopentadienylcarbonylmanganese chalcoꢀ
genide complexes, which cannot produce fulvene, giving
rise to manganeseꢀcontaining chalcogenides was also not
accompanied by the formation of metal oxides and carꢀ
bides regardless of the metal : chalcogen ratio.
Table 3. Bond lengths (d) and bond angles (ω) in the strucꢀ
ture of 8
Bond
d/Å
Angle
ω/deg
W/Cr(1)—Se(1) 2.548(1)
W/Cr(2)—Se(2) 2.567(2)
Se(1)—Se(2)—Mn(1) 62.91(5)
Se(1)—Se(2)—W(2) 107.46(4)
Mn(1)—Se(2)—W(2) 121.17(4)
Se(1)—Se(2)—Cr(2) 107.46(4)
Mn(1)—Se(2)—Cr(2) 121.17(4)
Se(2)—Se(1)—Mn(1) 62.48(5)
Se(2)—Se(1)—Cr(1) 110.37(5)
Mn(1)—Se(1)—Cr(1) 122.52(5)
Se(2)—Se(1)—W(1) 110.37(5)
Mn(1)—Se(1)—W(1) 122.52(5)
Se(2)—Se(1)
Se(2)—Mn(1)
Mn(1)—Se(1)
2.305(1)
2.507(2)
2.517(2)
(2.732 Å) and Te—Re (2.827 and 2.807 Å) bonds (Te—Mn
bonds are substantially shortened and are, on the average,
2.525 Å).8
Thermolysis of complexes 3—8 and other cyclopentaꢀ
dienyldicarbonylmanganese chalcogenides. Thermolysis of
complexes 3—8 under argon in the temperature range of
20—400 °C was studied in comparison with pyrolysis of
the starting complexes 1 and 2 as well as of other
cyclopentadienylcarbonylmanganese chalcogenides studꢀ
ied by us earlier.3
For example, pyrolysis of complexes 1, 2, and
[CpMn(CO)2]2S (11) (11 contains the monosulfide bridge
between the manganese atoms12) proceeded according to
Scheme 6
Chalcogenꢀcontaining complexes of some metals were
used in the pyrolytic synthesis of chalcogenide materials.9
The characteristic features of thermal decomposition of
metal carbonyls and Cp2Mꢀtype cene compounds were

2694
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003
Pasynskii et al.
Schemes 6—8, respectively, and was accompanied by an
exothermic peak in the thermograms (Fig. 5, a).
bridges, respectively,3 demonstrated that complex 12 melts
virtually without decomposition (m.p. = 131 1 °C, ∆mH =
37674 800 J mol–1), whereas complex 13 melts with deꢀ
composition, and subsequent pyrolysis of the complexes
occurs according to Schemes 9 and 10, respectively.
Scheme 7
Scheme 9
Scheme 8
Scheme 10
Study of thermolysis of the binuclear complexes
[CpMn(CO)2]2SMe2 (12) and [CpMn(CO)2]2SeMe2 (13)
containing the dimethylsulfide and dimethylselenide
Qexo
a
The total effect of each process is exothermic. Howꢀ
ever, the exothermic peaks in the thermograms of comꢀ
plexes 12 and 13, unlike those observed in thermolysis of
compounds 1, 2, and 11, have a complex shape (Fig. 5, b).
Solid products of thermolysis of complexes 2, 12, and
13 were studied by powder Xꢀray diffraction analysis
(Tables 4—6), which showed that the reaction products
100
200
300
400
T/°C
Qexo
b
Table 4. Data of powder Xꢀray diffraction analysis of the decomꢀ
position product of [CpMn(CO)2]2Se2 (2)
Decomposition
product
MnSe
I*
II**
50
100
150
200
250
300 T/°C
d/Å
I (%)
d/Å
I (%)
d/Å
I (%)
Qexo
3.115
2.731
2.580
2.153
1.933
1.857
1.702
1.578
20
100
20
20
60
80
10
30
3.100
2.770
2.590
2.160
—
1.810
1.690
1.520
5
—
20
25
—
80
5
3.141
2.720
—
—
1.923
—
10
100
—
—
60
—
c
—
1.570
—
20
10
50 100 150 200 250 300 350
T/°C
Fig. 5. Schematic representaion of the thermograms for decomꢀ
position of complexes 1, 2, 11 (a), 12, 13 (b), and 14 (c).
* Hexagonal modification.
** Cubic modification.

Thermal decomposition of manganese complexes
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003 2695
Table 5. Data of powder Xꢀray diffraction analysis of the decomꢀ
position product of [CpMn(CO)2]2SMe2 (12)
Table 7. Temperature dependence of the therꢀ
mal capacity of manganese selenide (MnSe)
Decomposition product
MnS
Mn
T/K
Cp/J K mol–1
Present
d/Å
I (%)
d/Å
I (%)
d/Å
I (%)
Lit.
data13
study
3.994
3.086
2.861
2.651
2.470
2.031
1.945
1.860
1.641
1.497
60
30
10
100
60
20
10
50
20
10
—
3.025
—
2.620
—
—
20
—
100
—
—
—
60
—
—
4.030
3.130
2.844
—
2.472
2.022
1.935
—
100
10
20
—
60
50
10
—
300
333
373
403
443
473
500
51.05
51.31
51.61
51.85
52.15
52.38
52.59
51.2
51.5
51.9
52.1
51.4
52.6
53.0
—
—
1.853
—
1.610
1.493
20
10
—
Scheme 11
Table 6. Data of powder Xꢀray diffraction analysis of the decomꢀ
position product of [CpMn(CO)2]2SeMe2 (13)
Decomposition product
MnSе
I (%)
Mn
d/Å
I (%)
d/Å
d/Å
I (%)
3.995
2.852
2.740
2.452
2.052
1.915
1.615
1.560
1.497
70
10
100
40
60
50
10
15
10
—
—
2.720
—
—
1.923
—
—
—
100
—
—
60
—
4.030
2.844
—
2.472
2.022
1.935
1.610
—
100
20
—
60
50
10
20
—
Powder Xꢀray diffraction analysis of the decomposiꢀ
tion products of complex 14 (Table 8) showed that the
resulting mixture contained manganese metal as well as
manganese monoꢀ and ditellurides.
1.570
—
20
—
1.493
10
contained manganese monochalcogenides. In addition,
thermolysis of complexes 12 and 13 afforded also mangaꢀ
nese metal.
Table 8. Data of powder Xꢀray diffraction analysis of the decomꢀ
position product of [CpMn(CO)2]3Te2 (14)
To correctly determine the composition of the solid
pyrolysis product of compound 2, we studied the temꢀ
perature dependence of the thermal capacity of the therꢀ
molysis product in the temperature range of 27—227 °C.
According to the powder Xꢀray diffraction data, this prodꢀ
uct is a nonequilibrium mixture of two modifications of
manganese selenide. Therefore, we carried out homoꢀ
genizing annealing at 800 °C in an inert atmosphere for 8 h.
A comparison of the results of measurements of thermal
capacity and the published data on manganese selenide13
demonstrated that they are in satisfactory agreement
within the experimental error (Table 7).
Thermolysis of the trinuclear telluride complex
[CpMn(CO)2]3Te2 (14) containing the cyclic MnTe2
group in which each Te atom is additionally coordinated
by the CpMn(CO)2 group14 proceeded stepwise accordꢀ
ing to Scheme 11 with considerable energy release. The
exothermic peak has a complex shape (Fig. 5, c).
Decomposition
product
MnТе
MnТе2
Mn
d/Å I (%)
d/Å I (%)
d/Å I (%)
d/Å I (%)
3.985
50
—
—
—
—
—
—
4.030
—
100
—
—
20
60
—
50
10
10
—
3.209 100
3.107 100
3.170 100
—
—
—
2.458
2.079
1.903
—
1.769
1.680
1.589
—
—
—
—
95
80
35
—
15
20
20
—
15
3.110 100
2.836
—
—
2.837
2.492
2.452
2.080
1.929
1.860
1.780
1.630
1.548
1.477
1.399
50
30
90
90
50
50
10
20
20
5
95
—
—
50
50
65
—
—
—
—
—
2.844
2.472
—
2.022
1.935
1.871
—
1.610
1.529
1.493
—
—
2.097
1.926
1.858
—
—
—
20
10
10
—
—
—
10
1.405

2696
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003
Pasynskii et al.
Qexo
Qexo
Qexo
Thermolysis of heterometallic cyclopentadienylcarboꢀ
nyl chalcogenide complexes 3—8 containing manganese
in combination with Group VI metals (Cr or W), which
were synthesized in the present study, proceeded analoꢀ
gously.
a
Thermal decomposition of compound 3 proceeded
according to Scheme 12.
100
200
300
400
T/°C
Scheme 12
b
50
100 150 200 250 300 350 T/°C
Elimination of the first two CO groups was accompaꢀ
nied by energy absorption. A further rise in temperature
led to elimination of the remaining CO groups and oneꢀ
half of the Cp groups with considerable energy release. In
the final step of decomposition accompanied by weak
energy absorption, the Cp groups were completely reꢀ
moved (Fig. 6, a). The total effect of the process is exoꢀ
thermic. Powder Xꢀray diffraction analysis of the solid
product of thermal destruction of complex 3 (Table 9)
revealed the presence of the MnSe and CrSe phases.
Thermal decomposition of isostructural complexes
4—7, in which the metallocycle MnX2 is additionally coꢀ
ordinated by two M(CO)5 groups, proceeded according
to Schemes 13—16, respectively.
c
100
200
300
400
T/°C
Fig. 6. Schematic representaion of the thermograms for decomꢀ
position of complexes 3 (a), 4, 5 (b), and 6, 7 (c).
Scheme 13
The energy changes in the course of thermal decomꢀ
position of compounds 4 and 5 (see Schemes 13 and 14)
are similar in character. The decomposition process starts
with partial elimination of the CO molecules and energy
Table 9. Data of powder Xꢀray diffraction analysis of the decomꢀ
position product of CpMn(CO)2Se2Cr(CO)5 (3)
Decomposition product
MnSе
I (%)
CrSe
I (%)
d/Å
I (%)
d/Å
d/Å
5.754
3.178
2.870
2.730
2.035
1.934
1.756
1.640
1.566
1.523
1.386
10
5
—
3.141
—
2.720
—
1.923
—
—
—
11
—
100
—
60
—
—
5.750
—
2.880
2.740
2.110
—
1.800
1.640
1.568
1.535
—
20
—
40
100
100
—
100
50
Scheme 14
30
100
80
40
60
40
20
20
10
1.570
—
1.366
20
—
11
10
50
—

Thermal decomposition of manganese complexes
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003 2697
Scheme 15
Qexo
50
100 150 200 250 300 350 T/°C
Fig. 7. Schematic representaion of the thermogram for decomꢀ
position of complex 8.
Scheme 16
exothermic effect upon the formation of new M—X and
M—M bonds, including the multiple metal—chalcogen
and metal—metal bonds.15 In particular, at the beginning
of decarbonylation of heterometallic complexes 4—7, the
partially multiple M—X bonds that appear should be stronꢀ
ger in the case of M = Cr than in the case of M = W,
whereas the multiple M—M bonds are more stronger in
the case of M = W.15
These effects are particularly difficult to take into acꢀ
count for mixed Cr,Wꢀcontaining complex 8 (Scheme 17).
Initially, the character of energy changes in the course
of thermal decomposition is analogous to that observed
for compounds 6 and 7. Then an increase of the temperaꢀ
ture leads to considerable energy release without a change
in the weight. The Cp ligand is eliminated with energy
absorption only in the last step (Fig. 7). The total effect of
decomposition is exothermic.
Therefore, complete decarbonylation is typical of this
class of cyclopentadienylcarbonyl chalcogenide comꢀ
plexes independently of the M : X ratio, whereas thermal
destruction of metal carbonyl chalcogenides with the
M : X ratio larger than unity gives rise to inorganic chalꢀ
cogenides with impurities of metal oxides and carbides.11
Apparently, this is associated with the characteristic
features of compensation of the electron deficiency,
which appears upon partial decarbonylation of comꢀ
plexes 1—8 and 11—14, compared to the carbonyl chalꢀ
cogenide complexes considered in the study.11 In the
latter complexes, structures with σ,πꢀcoordinated CO
groups, which donate a larger number of electrons to
the metal core compared to the terminal CO group,
should be generated as intermediates (for example, in
the Cp2Nb(µꢀCO)(σ,πꢀCO)Mo(CO)Cp16 (type А) or
Cp3Nb3(CO)717 (type B) clusters, in which the CO groups
are readily disrupted to form carbides and oxides due to
weakening of the C=O bonds).
release. Then, the majority of CO groups are removed
with considerable energy absorption. Finally, the Cp
ligand is eliminated with energy release (Fig. 6, b). In the
thermogram, the above process corresponds to the onset
of the exothermic effect, which is then superimposed with
the endothermic effect and completed with the exotherꢀ
mic effect. The total effect of thermal decomposition is
endothermic.
For compounds 6 and 7 (see Schemes 15 and 16,
respectively), the onset of thermal decomposition is acꢀ
companied by energy absorption. Then the process
is strongly exothermic with a weak endothermic dip
(Fig. 6, c). The total effect of thermolysis of compounds 6
and 7 is exothermic.
Apparently, the aboveꢀdescribed differences as well as
a substantial difference in the temperature at which therꢀ
mal decomposition was completed (250—270 °C for comꢀ
pounds 4 and 5, 320—440 °C for compounds 6 and 7) are
attributed to a superposition of the endothermic effect
associated with the cleavage of the M—CO bonds and the
Scheme 17
In the presence of the methylcyclopentadienyl ligands,
the electron deficiency, which appears upon elimination
of the carbonyl groups, can be compensated by the
transformation of the rings into the coordinated sixꢀelecꢀ

2698
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003
Pasynskii et al.
example, in the [RC5H4Fe(CO)2]2Sn(TePh)2 complexes,
where R = H (for Cp) or Me (for Cp*)20 (Scheme 19).
Scheme 19
tron donor fulvene ligand C5H4CH2 and the M—H bond
(Scheme 18).
Scheme 18
Therefore, even at M : X > 1, there is no need for the
formation of σꢀ,πꢀbridging CO ligands until CO groups
are completely eliminated.
The unsubstituted Cp ligands in complexes 1—8 and
11—14 considered in the presence study can, apparꢀ
ently, compensate the electron deficiency through the
σꢀ,πꢀbridging coordination of the Cp ligand with the adꢀ
ditional formation of the M—H bond, like in the strucꢀ
ture of dimeric niobocene18 (C), as well as through the
Therefore, the use of the Cp and Cp* ligands in carboꢀ
nyl chalcogenide complexes allows one to prevent the
formation of impurities of oxides and carbides in inorꢀ
ganic metal chalcogenides generated by pyrolysis at all
metal : chalcogen ratios in the complexes. It should be
noted that inorganic composites formed at relatively low
temperatures (below 450 °C) already consist of crystalline
phases of binary metal chalcogenides and individual
metals.
+
formation of stacked structures of the Cp3Ni2 type in
which the πꢀelectron system of the central Cp ligand is
involved in coordination to two metal atoms19 (D).
Experimental
All operations associated with the synthesis and isolation of
the complexes were carried out under pure argon and in anhyꢀ
drous solvents. Commercial CO, W(CO)6, and Cr(CO)6 were
used without preliminary purification. Complexes 1 and 2 were
synthesized according to a procedure published earlier.3
Thermal decomposition of compounds 1—8 and 11—14 was
studied by DSC and thermogravimetry on DSCꢀ20 and TGꢀ50
units of a TAꢀ3000 thermoanalyzer (Mettler). In all experiꢀ
ments, samples were heated under dry argon at a constant rate
(5 K min–1). Three—four DSC experiments and three—five
TGA experiments were carried out for each compound. The
weight loss upon thermal destruction was determined directly
on a TGꢀ50 unit; the accuracy of the weighing device was
2•10–3 mg. Thermal destruction was studied by DSC in steps,
the temperature range of investigation being divided into interꢀ
vals. The width and number of these intervals were determined
based on the preliminary general information on the changes in
the weight and energy in the course of decomposition. This
The methylcyclopentadienyl ligand also can compenꢀ
sate the electron deficiency in this way. However, the
aboveꢀmentioned assumption (fulvene scheme) adequaꢀ
tely explains a sharp decrease in the temperature of comꢀ
plete thermal decomposition of the methylcyclopentaꢀ
dienyl complexes compared to the analogous cycloꢀ
pentadienyl complexes, as we have observed earlier, for

Thermal decomposition of manganese complexes
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003 2699
method of performing the experiment made it possible to deterꢀ
mine the weight loss in each temperature interval and compare
the results obtained by DSC and TGA. The anomalous points
and thermal effects in the thermograms were determined with
an accuracy of 1° and 0.5%, respectively.
C5H5, 11.5*. C17H5Cr2MnO12S2. Calculated (%): CO, 53.8;
C5H5, 10.4. IR, ν/cm–1: 2035 s, 1940 v.s, 1910 v.s, 835 m, 630 s,
555 w, 430 w.
(Cyclopentadienyldicarbonylmanganese)(µꢀdisulfide)bis(penꢀ
tacarbonyltungsten), [CpMn(CO)2](µꢀS2)[W(CO)5]2 (6). A soꢀ
lution of W(CO)6 (0.5 g, 1.42 mmol) in THF (30 mL) was
irradiated with UV light in a waterꢀcooled quartz Schlenk vessel
for 1.5 h. The resulting orange solution was added dropwise to a
green solution of [CpMn(CO)2]2(µꢀS2) (0.3 g, 0.72 mmol) in
THF (20 mL) at 15 °C for 1.5 h. The reaction mixture was
stirred for 1 h and the solvent was removed in vacuo. The green
residue was washed with hexane (40 mL) and extracted with
CH2Cl2 (20 mL). The extract was concentrated to 1/3 of the
initial volume, hexane (5 mL) was added, and the solution was
kept at –18 °C to obtain rhombic green crystals. The yield of
compound 6 was 0.06 g (10%). Found (%): C, 23.56; S, 6.53;
CO*, 37.5; C5H5*, 8.0. C17H5MnO12S2W2. Calculated (%):
C, 23.0; S, 7.2; CO, 37.8; C5H5, 7.3. IR, ν/cm–1: 2055 s, 2040 m,
1930 s, 1900 v.s, 830 w, 665 w.
The IR spectra were recorded on a Specord IRꢀ75 spectroꢀ
photometer in KВr pellets.
(Cyclopentadienyldicarbonylmanganese)(µꢀdiselenide)(pentaꢀ
carbonylchromium), [CpMn(CO)2](µꢀSe2)[Cr(CO)5] (3). A soꢀ
lution of Cr(CO)6 (0.34 g, 1.5 mmol) in THF (30 mL) was UV
irradiated in a waterꢀcooled quartz Schlenk vessel for 1.5 h. The
resulting orange solution was added dropwise to a green solution
of [CpMn(CO)2]2(µꢀSe2) (0.4 g, 0.78 mmol) in THF (20 mL) at
0 °C for 1.5 h. The grayꢀgreen reaction mixture was stirred for
1 h and concentrated to dryness in vacuo. The green residue was
washed with hexane (40 mL) and extracted with CH2Cl2 (30 mL).
The green extract was concentrated to dryness in vacuo and the
green residue was extracted with THF (30 mL). Gaseous CO
was bubbled through the resulting violet solution (1 bubble
per second) with stirring for 5 h. The solvent was removed in
vacuo. The residue was recrystallized from a CH2C12—hexane
mixture after storage of the solution at –18 °C for 72 h. Comꢀ
pound 3 was obtained in a yield of 0.24 g (58%) as needleꢀlike
violet crystals suitable for Xꢀray diffraction analysis. Found (%):
CO, 37.5*; C5H5; 12.3* (solid residue corresponds to MnCrSe2).
C12H5MnO7Se2. Calculated (%): CO, 37.3; C5H5, 12.3. IR,
ν/cm–1: 2040 m, 1990 s, 1960 s, 1920 v.s, 1885 v.s, 1415 w,
1020 w, 1005 w, 845 m, 630 s, 555 m.
( C y c l o p e n t a d i e n y l d i c a r b o n y l m a n g a n e s e ) ( µ ꢀ d i ꢀ
selenide)bis(pentacarbonyltungsten),
[CpMn(CO)2](µꢀ
Se2)[W(CO)5]2 (7). The synthesis was carried out analogously to
that described above for complex 6 starting from a solution of
W(CO)6 (0.41 g, 1.17 mmol) in THF (30 mL) and a solution of
compound 2 (0.3 g, 0.58 mmol) in THF (20 mL). Rhombicꢀlike
darkꢀgreen crystals were prepared by recrystallization from a
dichloromethane—hexane mixture. The yield of compound 7
was 0.07 g (15%). Found (%): C, 21.69; (CO + C5H5)*, 40.3.
C17H5MnO12Se2W2. Calculated (%): C, 20.8; (CO + C5H5)
40.8. IR, ν/cm–1: 2005 s, 1980 s, 1880 v.s, 1855 v.s, 1370 w,
1000 w, 880 w, 820 w, 785 m, 510 s.
( C y c l o p e n t a d i e n y l d i c a r b o n y l m a n g a n e s e ) ( µ ꢀ d i ꢀ
selenide)bis(pentacarbonylchromium),
[CpMn(CO)2](µꢀ
Se2)[Cr(CO)5]2 (4). A solution of Cr(CO)6 (0.25 g, 1.13 mmol)
in THF (20 mL) was irradiated with UV light in a waterꢀcooled
quartz Schlenk vessel for 1.5 h. A green solution of 2 (0.3 g,
0.58 mmol) in THF (20 mL) was added to the resulting orange
solution. After stirring for 1 h, the color of the solution changed
to grayꢀgreen. The solution was concentrated to dryness in vacuo.
The green residue was washed with hexane (40 mL) and exꢀ
tracted with diethyl ether (50 mL). The green extract was conꢀ
centrated to 1/3 of the initial volume. Then hexane (5 mL) was
added and the solution was kept at –18 °C. The residue was
extracted with CH2Cl2 (30 mL), the extract was concentrated to
1/2 of the initial volume, and hexane (4 mL) was added. Storage
of both solutions (which are identical according to the results of
IR spectroscopy and TLC) at –18 °C for 24 h afforded a darkꢀ
green crystalline precipitate. Rhombicꢀlike prismatic crystals
were filtered off and washed with hexane. The total yield of
compound 4 was 0.15 g (35.7%) (single crystals). Found (%):
C, 28.5; H, 0.2; CO, 46.0*; C5H5, 8.0*. C17H5Cr2MnO12Se2.
Calculated (%): C, 28.4; H, 0.7; CO, 46.0; C5H5, 9.0. IR,
ν/cm–1: 2068 m, 2048 s, 2032 m, 1940 s, 1912 s, 849 w, 640 s,
560 w, 448 w.
(Cyclopentadienyldicarbonylmanganese)(µꢀdiseleꢀ
nide)(pentacarbonylchromium)(pentacarbonyltungsten),
[CpMn(CO)2](µꢀSe2)[Cr(CO)5][W(CO)5] (8). A solution of
W(CO)6 (0.2 g, 0.57 mmol) in THF 30 mL was irradiated with
UV light in a quartz Schlenk vessel for 3 h. The resulting yellowꢀ
brown solution was added dropwise to a lilacꢀcolored solution of
compound 3 (0.24 g, 0.45 mmol) in THF (20 mL) with cooling
in an ice bath at 0 °C for 2 h. The darkꢀyellowꢀbrown reaction
mixture was stirred for 1 h and then concentrated to dryness in
vacuo. The darkꢀgreen residue was washed with hexane (30 mL)
and extracted with CH2C12 (30 mL). The yellowishꢀgreen exꢀ
tract was filtered through a SiO2 layer and concentrated to 1/3 of
the initial volume. Then hexane (18 mL) was added and the
solution was kept at –18 °C for 24 h. The rhombicꢀlike darkꢀ
green crystals that precipitated were used for Xꢀray diffraction
analysis. The yield of compound 8 was 0.11 g (23%). Found (%):
C, 24.07; CO, 39.5*; C5H5, 7.6*. C17H5Se2CrMnO12W. Calcuꢀ
lated (%): C, 24.02; CO, 39.5; C5H5, 7.6. IR, ν/cm–1: 2040 s,
2015 s, 1930 v.s, 1905 v.s, 1610 w, 820 w, 580 s, 500 m.
Xꢀray diffraction analysis. The crystallographic data, details
of Xꢀray diffraction study, and characteristics of the structure
refinement of compounds 3, 4, 6, and 8 are given in Table 1. The
structures were solved by direct methods and refined by the fullꢀ
matrix leastꢀsquare method with anisotropic and isotropic therꢀ
mal parameters for nonhydrogen and H atoms, respectively. All
calculations were carried out with the use of the SHELXTL
PLUS 5 program package.21 The principal geometric paramꢀ
eters for the structures of 3, 4, 6, and 8 are given in Tables 2
and 3. The atomic coordinates and thermal parameters were
deposited with the Cambridge Structural Database: CCDC
(Cyclopentadienyldicarbonylmanganese)(µꢀdisulfide)bis(penꢀ
tacarbonylchromium), [CpMn(CO)2](µꢀS2)[Cr(CO)5]2 (5). The
synthesis was carried out as described above for complex 4 startꢀ
ing from a solution of Cr(CO)6 (0.31 g, 1.44 mmol) in THF
(20 mL) and a solution of compound 1 (0.2 g, 0.48 mmol) in
THF (20 mL). Darkꢀgreen crystals were prepared by recrystalliꢀ
zation from a diethyl ether—hexane mixture. Compound 5 was
obtained in a yield of 0.08 g (18%). Found (%): CO, 52.0*;
* Hereinafter, the DSC data are marked with asterisks.

2700
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 12, December, 2003
Pasynskii et al.
215210 (3), CCDC 215211 (4), CCDC 215212 (6), and CCDC
215213 (8).
8. H. Brunner, G. Gehart, S.ꢀC. Leblanc, C. Moise, and
B. Nuber, J. Organomet. Chem., 1996, 517, 47.
9. S. V. Larionov and S. M. Zemskova, Ross. Khim. Zh., 1996,
40, 171 [Mendeleev Chem. J., 1996, 40 (Engl. Transl.)].
10. V. G. Syrkin, CVDꢀMetod. Khimicheskoe parofaznoe
osazhdenie [CVD Method: Chemical VaporꢀPhase Precipitaꢀ
tion], Nauka, Moscow, 2000, 496 pp. (in Russian).
11. A. A. Pasynskii, Zh. V. Dobrokhotova, N. I. Semenova,
Yu. V. Torubaev, and V. M. Novotortsev, Izv. Akad. Nauk,
Ser. Khim., 2003, 103 [Russ. Chem. Bull., Int. Ed., 2003,
52, 109].
12. M. Hoefler and A. Baitz, Chem. Ber., 1976, 109, 3147.
13. J. Barin, O. Knacke, and O. Kubaschewski, Thermochemical
Properties of Inorganic Substances, SpringerꢀVerlag, Berꢀ
lin—Heidelberg—New York, 1977.
We thank K. A. Lyssenko (Center of Xꢀray Diffracꢀ
tion Studies, A. N. Nesmeyanov Institute of Organoꢀ
element Compounds, Russian Academy of Sciences) for
help in establishing the structures of the complexes.
This study was financially supported by the Russian
Foundation for Basic Research (Project Nos. 03ꢀ03ꢀ
32730, 03ꢀ03ꢀ06518, 03ꢀ03ꢀ06519, 02ꢀ03ꢀ33041, and
MLꢀ99ꢀ2) and the Chemistry and Materials Science Diꢀ
vision of the Russian Academy of Sciences (Program No. 7
for Basic Research).
14. А. A. Pasynskii and Yu. V. Torubaev, Abstrs. of 34th Intern.
Conf. on Coordination Chemistry, Edinburg, Scotland,
2000, P0815.
References
1. А. A. Pasynskii, I. L. Eremenko, S. E. Nefedov, B. I.
Kolobkov, A. D. Shaposhnikova, R. A. Stadnichenko, M. V.
Drab, Yu. T. Struchkov, and A. I. Yanovsky, Nouv. J. Chim.,
1994, 18, 69.
2. M. Herberhold, D. Reiner, B. ZimmerꢀGasser, and
U. Shubert, Z. Naturforsch., 1980, 35, 1281.
3. A. A. Pasynskii, V. N. Grigor´ev, Yu. V. Torubaev, K. A.
Lyssenko, Zh. V. Dobrokhotova, V. V. Minin, and V. A.
Grinberg, Zh. Neorg. Khim., 2002, 47, 1987 [Russ. J. Inorg.
Chem., 2002, 47 (Engl. Transl.)].
4. A. A. Pasynskii, B. I. Kolobkov, I. L. Eremenko, S. E.
Nefedov, S. B. Katser, and M. A. PoraiꢀKoshits, Zh. Neorg.
Khim., 1992, 37, 563 [Russ. J. Inorg. Chem., 1992, 37 (Engl.
Transl.)].
5. K. Kuge, H. Tobits, and H. Ogino, J. Chem. Soc., Chem.
Commun., 1999, 1061.
15. F. A. Cotton and R. A. Walton, Multiple Bonds Between
Metal Atoms, J. Wiley and Sons, New York, 1982.
16. A. A. Pasynskii, Yu. V. Skripkin, I. L. Eremenko, V. T.
Kalinnikov, G. G. Aleksandrov, V. G. Andrianov, and Yu. T.
Struchkov, J. Organomet. Chem., 1979, 165, 49.
17. W. A. Herrmann, M. L. Ziegler, K. Weidenhammer, and
H. Biersack, Angew. Chem., Int. Ed. Engl., 1979, 18, 960.
18. L. J. Guggenberger, Inorg. Chem., 1973, 12, 294.
19. E. Dudler, M. Textor, H.ꢀR. Oswald, A. Salzer, and G. B.
Jameson, Acta Crysttallogr., Sect. B, 1983, 39, 607.
20. A. A. Pasynskii, Yu. V. Torubaev, F. S. Denisov, A. N.
Grechkin, K. A. Lyssenko, S. N. Nefedov, V. M.
Novotortsev, and Zh. V. Dobrokhotova, Izv. Akad. Nauk,
Ser. Khim., 1999, 1766 [Russ. Chem. Bull., 1999, 48, 1744
(Engl. Transl.)].
21. SMART (Control) and SAINT (Integration) Software, Verꢀ
sion 5.0, Bruker AXS Inc., Madison, WI, 1997.
6. S. Stauf, C. Reisner, and W. Tremel, J. Chem. Soc., Chem.
Commun., 1996, 1749.
7. M. L. Steigerwald and C. E. Rice, J. Am. Chem. Soc., 1988,
110, 4228.
Received July 4, 2003;
in revised form October 31, 2003