Synthesis and reactivity of W3Te74+ clusters and chalcogen exchange in the M3Q7 (M = Mo, W; Q = S, Se, Te) cluster family

Article abstract of DOI:10.1021/ic050962c

Heating WTe₂, Te, and Br₂ at 390°C followed by extraction with KCN gives [W₃Te₇(CN)₆] ^2-. Crystal structures of double salts Cs_3.5K{[W ₃Te₇(CN)₆]Br}Br_1.5·4.5H ₂O (1), Cs₂K₄{[W₃Te ₇(CN)₆]₂Cl}Cl·5H₂O (2), and (Ph₄P)₃{[W₃Te₇-(CN) ₆]Br}·H₂O (3) reveal short Te₂...X (X = Cl, Br) contacts. Reaction of polymeric Mo₃Se₇Br ₄ with KNCSe melt gives [Mo₃Se₇(CN) ₆]^2-. Reactions of polymeric Mo₃S ₇Br₄ and Mo₃Te₇I₄ with KNCSe melt (200-220°C) all give as final product [Mo₃Se ₇(CN)₆]^2- via intermediate formation of [Mo₃S₄Se₃(CN)₆]^2-/ [Mo₃SSe₆(CN)₆]^2- and of [Mo ₃Te₄Se₃(CN)₆]^2-, respectively, as was shown by ESI-MS. (NH₄)_1.5K ₃{[Mo₃Se₇(CN)₆]I}I _1.5·4.5H₂O (4) was isolated and structurally characterized. Reactions of W₃Q₇Br₄ (Q = S, Se) with KNCSe lead to [W₃Q₄(CN)₉]^5-. Heating W₃Te₇Br₄ in KCNSe melt gives a complicated mixture of W₃Q₇ and W₃Q₄ derivatives, as was shown by ESI-MS, from which E₃[W ₃(μ₃-Te)(μ-TeSe)₃(CN)₆] Br·6H₂O (5) and K₅[W₃(μ₃- Te)(μ-Se)₃(CN)₉] (6) were isolated. X-ray analysis of 5 reveals the presence of a new TeSe^2- ligand. The complexes were characterized by IR, Raman, electronic, and ⁷⁷Se and ¹²⁵Te NMR spectra and by ESI mass spectrometry.

Full text of DOI:10.1021/ic050962c

Inorg. Chem. 2005, 44, 8116−8124
Synthesis and Reactivity of W Te74+ Clusters and Chalcogen Exchange
3
in the M Q (M
) Mo, W; Q ) S, Se, Te) Cluster Family
3
7
Maxim N. Sokolov,*,† Pavel A. Abramov,† Artem L. Gushchin,† Irina V. Kalinina,† Dmitry Y. Naumov,†
Alexander V. Virovets, Eugenia V. Peresypkina,† Cristian Vicent,‡ Rosa Llusar,‡ and
†
†
Vladimir P. Fedin
NikolayeV Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences,
LaVrentieV AVenue 3, NoVosibirsk 630090, Russia, and Departament de Ciencies Experimentals,
UniVersitat Jaume I, Castellon, Spain
Received June 14, 2005
Heating WTe
double salts Cs3.5
2
, Te, and Br
[W Te
2
at 390
°
C followed by extraction with KCN gives [W
4.5H O (1), Cs [W Te (CN) Cl Cl
Cl, Br) contacts. Reaction of polymeric Mo
3
Te
7
(CN)
O (2), and (Ph
Se Br with KNCSe melt
with KNCSe melt (200 220 C) all give as
Se (CN) SSe (CN)
]2-/[Mo ]2- and of
[Mo Se (CN) ]I 4.5H O (4) was isolated
S, Se) with KNCSe lead to [W (CN)
]5-. Heating
and W derivatives, as was shown by ESI-MS,
-Te)( -Se) (CN) ] (6) were isolated. X-ray analysis
6
]2-. Crystal structures of
P) [W Te
K{
3
7
(CN) ]Br
6
}
Br1.5
‚
2
2
K
4
{
3
7
6
]
2
}
‚
5H
2
4
3
{
3
7
-
(
CN)
gives [Mo
final product [Mo
6
]Br}‚
H
2
O (3) reveal short Te
2
‚‚‚X (X
)
3
7
4
-
]2 . Reactions of polymeric Mo
3
Se
7
(CN)
6
S Br
3 7 4
3 7
and Mo Te I
4
−
°
-
]2 via intermediate formation of [Mo
3
Se
7
(CN)
6
3
S
4
3
6
3
6
6
-
]2 , respectively, as was shown by ESI-MS. (NH
[
Mo
and structurally characterized. Reactions of W
Te Br in KCNSe melt gives a complicated mixture of W
from which E [W -Te)( -TeSe) (CN) ]Br 6H O (5) and K [W
3
Te
4
Se
3
(CN)
6
4 1.5 3
) K {
3
7
6
}I
1.5
‚
2
3
Q
7
Br (Q
4
)
3
Q
4
9
W
3
7
4
3
Q
7
3 4
Q
ˆ
3
3 3
(µ
µ
3
6
‚
2
5
3 3
(µ
µ
3
9
2
-
of 5 reveals the presence of a new TeSe ligand. The complexes were characterized by IR, Raman, electronic,
and 77Se and 125Te NMR spectra and by ESI mass spectrometry.
Introduction
one can expect an easy replacement of Te by other bridging
ligands with the cluster core retention. Cluster cyanides have
drawn much attention in recent years as building blocks for
coordination polymers, in particular for those with large
Metal telluride clusters remain the least studied members
of the chalcogenide cluster family.1-6 The large size, diffuse
orbitals, and increased metallic character of tellurium make
it an attractive cluster-supporting bridging ligand, often with
a quite different behavior, in comparison with a rather sulfur-
cavities and high porosity. Both tetrahedral {M
4 4
Q (CN)12}
and octahedral {M (CN) } (M ) Mo, W, Re; Q ) S, Se,
6
Q
8
6
9
,10
7
Te) units were used for these purposes. In this contribution
we report the synthesis and structures of new trinuclear
chalcogenide cluster cyanides, [W
like selenium. A strong tendency of tellurium to participate
in secondary nonvalence intermolecular interactions, already
observable in elemental Te, makes a strong case for using
tellurium-containing building blocks in supramolecular chem-
2
-
3
Te
7
(CN)
6
]
3
and [Mo -
2-
Se (CN) ] , as well as the use of KNCSe melt for introduc-
7 6
8
tion of Se into cluster cores with the retention of the metal
framework, which allows one to obtain new mixed Se/Te
istry. On the other hand, the M-Te bonds are weak and
2
-
5-
*
To whom correspondence should be addressed. E-mail: caesar@
clusters [W
Te
4
Se
3
(CN)
6
]
3 3 9
and [W TeSe (CN) ] .
3
che.nsk.su.
†
Siberian Branch of the Russian Academy of Sciences.
Universitat Jaume I.
‡
(8) Smith, D. M.; Ibers, J. A. Coord. Chem. ReV. 2000, 200-202, 187.
(9) (a) Fedin, V. P.; Virovets, A. V.; Kalinina, I. V.; Ikorskii, V. N.;
Elsegood, M. R. J.; Clegg, W. Eur. J. Inorg. Chem. 2000, 2341. (b)
Fedin, V.; Kalinina, I.; Gerasimenko, A.; Virovets, A. Inorg. Chim.
Acta 2002, 331, 48. (c) Kalinina, I. V.; Virovets, A. V.; Dolgushin,
F. M.; Antipin, M. Yu.; Llusar, R.; Fedin, V. P. Inorg. Chim. Acta
2004, 357, 3390. (d) Fedin, V. P.; Kalinina, I. V.; Virovets, A. V.;
Fenske, D. Russ. Chem. Bull., Int. Ed. 2003, 52, 126.
(
(
(
1) Kolis, J. W. Coord. Chem. ReV. 1990, 105, 195.
2) Roof, L. C.; Kolis, J. W. Chem. ReV. 1993, 93, 1037.
3) Fenske, D.; Corrigan, J. F. In Metal Clusters in Chemistry; Braunstein,
P., Oro, L. A., Raithby, P. R., Eds.; Wiley-VCH: Weinheim, Germany,
1
999; Vol. 3, p 1303.
(
(
4) Kalinina, I. V.; Fedin, V. P. Russ. J. Coord. Chem. 2003, 29, 597.
5) Sokolov, M. N.; Fedin, V. P.; Sykes, A. G. Comp. Coord. Chem. 2
2
003, 4, 761.
(10) (a) Brylev, K. A.; Sekar, P.; Naumov, N. G.; Fedorov, V. E.; Ibers, J.
Inorg. Chim. Acta 2004, 357, 738. (b) Mironov, Y. V.; Fedorov, V.
E.; Ijjaali, I.; Ibers, J. A. Inorg. Chem. 2001, 40, 6320.
(
(
6) Sokolov, M. N.; Fedin, V. P. Coord. Chem. ReV. 2004, 248, 925.
7) Wachter, J. Eur. J. Inorg. Chem. 2004, 1367.
8116 Inorganic Chemistry, Vol. 44, No. 22, 2005
10.1021/ic050962c CCC: $30.25
© 2005 American Chemical Society
Published on Web 09/27/2005

4+
3
W Te
7
Clusters
(CN)
(
(
6
]2 (800.4; 75), [W
609.0; 18), {Cs[W Te (CN)
1478.5; 13).
Synthesis of (Ph
solution of Ph PBr (0.17 g, 0.41 mmol) in 6 mL of hot water was
added to a solution of 1 (0.20 g, 0.084 mmol) in 4 mL of H O.
-
3
Te
5
(CN)
6
]2- (672.8; 100), [W
3
Te
Te
4
(CN)
(CN)
6
]2-
6
]}
Experimental Section
-
-
3
7
6
]} (1733.8; 10), {Cs[W
3
5
3 7 4 3 7 4
Materials and Methods. Mo Te I and the bromides M Q Br
(M ) Mo, W; Q ) S, Se) were prepared by heating stoichiometrical
4
P)
3
{[W
3 3
(µ -Te)(µ
2 2 3 6 2
-Te ) (CN) ]Br}‚H O, 3. A
mixtures of elements (350 °C, 4 days) according to the published
4
procedure.1 WTe
1,12
was prepared from the elements. All the other
13
2
2
reagents were purchased from commercial sources and used without
further purification. Hygroscopic KNCSe (Aldrich) was used
immediately after opening and kept over P O10. The reactions with
4
KNCSe were run under argon, and all the other manipulations were
done in air.
The red-brown precipitate was collected by filtration, washed with
water, and dried. Yield of the crude product: 0.23 g (100%). Dark-
brown needlelike crystals of 3 were obtained after ether vapor
diffusion into acetone solution. Anal. Calcd for C H BrN OP -
78
62
6
3
Te W : C, 34.48; H, 2.30; N, 3.09. Found: C, 34.31; H, 2.27; N,
7
3
-
1
Elemental analyses were carried out by the Novosibirsk Institute
3.39. IR (KBr), cm : 2098, 2047 (νCN).
Synthesis of (NH {[Mo (µ -Se)(µ -Se
4. A mixture of Mo (1.00 g, 0.59 mmol) and KCNSe (1.67
of Organic Chemistry microanalytical service. IR spectra (4000-
) K
4 1.5 3
3
3
2
2
)
3
(CN)
6 2
]I}I1.5‚4.5H O,
-
1
4
00 cm ) were recorded on an IFS-85 Fourier spectrometer
Bruker). Raman spectra were obtained on a Triplimate SPEX
spectrometer using the 632.8 nm line of a He-Ne laser for
3 7 4
Te I
(
g, 11.59 mmol) was heated in argon at 200-220 °C for 2 h. The
reaction product was extracted with 10 mL of water. The solution
was left in an open beaker for 2 days. The red-brown microcrys-
talline product was collected by filtration, washed with ethanol,
and dried in air. Yield: 0.21 g (23%). Analysis (EDAX): K:Mo:
excitation. 77Se NMR and Te NMR spectra were run on a SXP/
125
3
2
00 spectrometer (Bruker) with saturated aqueous solutions of H -
as standards. The chemical shifts for 77Se spectra
SeO and H TeO
were recalculated vs Me Se. A Quattro LC (quadrupole-hexapole-
3
6
6
-1
Te:Se ) 3.0:3.0:0.0:7.3. IR (KBr), cm : 2107, 2063 (νCN). Raman
2
-
1
(
cm ): 560 w, 437 w, 395 w, 352 w, 305 vs, 290 sh, 265 sh, 253
quadrupole) mass spectrometer with an orthogonal Z-spray-
electrospray interface (Micromass, Manchester, U.K.) was used.
The drying gas as well as nebulizing gas was nitrogen at a flow
rate of 400 and 80 L/h, respectively. Sample solutions in methanol
were infused via syringe pump directly to the interface at a flow
rate of 6 µL/min. A capillary voltage of 3.5 kV was used in the
negative scan mode, and the cone voltage was varied between -10
to -60 V. The chemical composition of each peak was assigned
7
7
vs, 218 w, 201 w, 189 w, 177 s, 154 s, 118 w, 89 sh, 63 m. Se
NMR (57 MHz, H O, 25 °C): δ ) 615.7, 90.5, -246.8 ppm.
Synthesis of K {[W (µ -Te)(µ -SeTe) (CN) ]Br}‚6H O, 5. A
mixture of WTe (8.00 g, 18.22 mmol), Te (0.78 g, 6.11 mmol),
and Br (1.90 g, 11.89 mmol) was heated in an evacuated glass
ampule at 390 °C for 2 days. A mixture of “W Te Br ” (1.00 g,
.57 mmol) and KCNSe (0.24 g, 1.66 mmol) was heated in argon
2
3
3
3
2
3
6
2
2
2
3
7
4
0
at 190 °C for 1 h. The reaction product was extracted with 10 mL
of water. The solution was left in air for 2 days. The red precipitate
of Se appeared, which was removed by filtration. The dark-red
crystals were obtained by evaporation of the solution. Yield: 0.072
g (7%). Analysis (EDAX): K:W:Te:Se ) 3.0:3.0:4.1:3.1.
by comparison of calculated and observed isotope patterns using
the MassLynx 3.5 program.14
Synthesis of Cs3.5K{[W
. A mixture of WTe (8.00 g, 18.22 mmol), Te (0.78 g, 6.11
mmol), and Br (1.90 g, 11.89 mmol) was heated in an evacuated
glass ampule at 390 °C for 2 days. The resulting solid reaction
product (4.00 g) was refluxed in 15 mL of H O with KCN (2.00 g,
0.69 mmol) for 1.5 h. The reaction solution was filtered. To the
3
(µ
3
-Te)(µ
2
-Te
2
)
3
(CN)
6 2
]Br}Br1.5‚4.5H O,
1
2
2
5 3 3 2 3 9
Synthesis of K [W (µ -Te)(µ -Se) (CN) ], 6. KCN (0.095 g,
1.46 mmol) was added to the solution obtained in the synthesis of
2
5
after removal of red selenium. The mixture was stirred for 4 h.
3
The gray precipitate of Te appeared, which was removed by
filtration.
Dark-green crystals were obtained by evaporation of the filtrate.
Yield: 0.031 g (4%). Analysis (EDAX): K:W:Te:Se ) 5.1:3.0:
intensely colored red-brown solution was added CsCl (1.50 g, 8.91
mmol). Slow evaporation in air gave a crystalline product. Yield:
6 9 6 7 3
1.17 g (22%). Anal. Calcd for C H Br2.5Cs3.5N O4.5KTe W : C,
3
.02; H, 0.38; N, 3.52. Found: C, 3.03; H, 0.49; N, 3.85. IR (KBr),
3
.1:1.0. UV-vis (water; λ, nm): 351, 392, 600.
Synthesis of K [W (CN) ], 7. A 1.00 g amount of W
0.91 mmol) and 2.00 g of KCNSe (13.88 mmol) were heated 3 h
-1
125
cm : 2088 (νCN). Te NMR (95 MHz, H
494.8, -1438.6 ppm.
Synthesis of Cs {[W
A solution of 1 (0.10 g, 0.042 mmol) in 4 mL of H
to a solution of CsCl (0.54 g, 3.21 mmol) in 2 mL of H
2
O, 25 °C): δ ) -36.1,
5
S
3 4
9
3 7 4
S Br
-
(
K
2 4
3
(µ
3
-Te)(µ
2
-Te
2
)
3
(CN)
6
]
2
Cl}Cl‚5H
O was added
O. The
2
O, 2.
at 180 °C. The solidified melt was extracted with water (20 mL).
The blue solution was filtered, and THF was added until an oil
separated. After addition of ethanol to the oil, a dark blue precipitate
2
2
dark-red crystals were obtained by slow evaporation in air of the
mixture. Yield: 0.070 g (86%). The complex is air stable and well
of 7 was obtained. Yield: 0.20 g (20%). Analysis (EDAX): K:W:
5-
S:Se ) 5.1:3.0:4.1:0.1. [W
S
3 4
(CN)
9
]
was identified by the UV-
2 2 12 5 4 6
soluble in water. Anal. Calcd for C12H10Cs Cl N O K Te14W : C,
-1
-1
24
vis spectrum (water; λ/nm, ꢀ/M cm ): 579 (370).
3
.81; H, 0.27; N, 4.44. Found: C, 3.77; H, 0.44; N, 4.01. IR (KBr),
Synthesis of K
(0.70 mmol) and 2.50 g of KCNSe (17.35 mmol) were heated
h at 180 °C. The solidified melt was extracted with water (20
5 3 4 9 3 7
[W Se (CN) ], 8. A 1.00 g amount of W Se -
-
1
cm : 2091, 2061 (νCN). ES-MS (CH
3
OH) (m/z; I, %): [W
3 7
Te -
Br
3
4
(
(
11) (a) Fedin, V. P.; Sokolov, M. N., Virovets, A. V.; Podberezskaya, N.
mL). The green solution was filtered, and THF was added until an
oil separated. After addition of ethanol to the oil, a dark green
precipitate of 8 was obtained. Yield: 0.15 g (17%). Analysis
V.; Fedorov, V. Ye. Polyhedron 1992, 11, 2973. (b) Fedin, V. P.;
Sokolov, M. N.; Gerasko, O. A.; Kolesov, B. A.; Fedorov, V. E,
Mironov, Yu. V.; Yufit, D. S.; Slovokhotov, Yu. L.; Struchkov, Yu.
T. Inorg. Chim. Acta 1990, 175, 217. (c) Fedin, V. P.; Sokolov, M.
N.; Myakishev, K. G.; Gerasko, O. A.; Fedorov, V. Ye.; Maci e` ek, J.
Polyhedron 1991, 10, 1311.
5-
(EDAX): K:W:Se ) 5.0:3.1:4.1. [W
by the UV-vis spectrum (water; λ/nm, ꢀ/M cm ): 611 (860).
3
Se
4
(CN)
9
]
was identified
-1
-1
24
77
2
Se NMR (57 MHz, H O, 25 °C): δ ) 1666.1, 1133.5 ppm.
12) (a) Fedin, V. P.; Imoto, H.; Saito, T.; McFarlane, W.; Sykes, A. G.
Inorg. Chem. 1995, 34, 5097. (b) Fedin, V. P.; Fedorov, V. Ye.; Imoto,
H.; Saito, T. Zh. Neorg. Khim. 1997. 42, 1963-1973. (c) Pervukhina,
N. V.; Podberezskaya, N. V.; Kalinina, I. V.; Fedin, V. P. Zh. Strukt.
Khim. 2000, 5, 1027.
X-ray Structure Crystallography. Crystals of the complexes
1-6 suitable for X-ray diffraction were obtained as described above.
Hemispherical data sets for 1, 2, and 4-6 were collected at T )
150 K (5, 6) or room temperature (1, 2) on a four-circle Bruker-
(13) Brixner, L. H. J. Inorg. Nucl. Chem. 1962, 24, 257.
14) Masslynx 3.2; Micromass: Manchester, U.K., 1998.
(
Nonius X8Apex CCD diffractometer using an optimized strategy
Inorganic Chemistry, Vol. 44, No. 22, 2005 8117

Sokolov et al.
Table 1. Selected Crystal and Refinement Data for 1-6
param
formula
1
2
3
4
5
6
C6H9Br2.5Cs3.5N6O4.5- C12H10Cs2Cl2N12O5- C78H62BrN6OP3Te7W3 C6H15I2.5Mo3N7.5O4.5- C6BrN6O6-
C9N9K5Se3TeW3
KTe7W3
2386.00
K4Te14W6
3784.94
K3Se7
1539.35
P 3h c, 4
12.9160(15)
12.9160(15)
23.080(6)
90
90
120
3334.4(10)
11.470
3.066
K3Se3Te4W3
1748.16
P21, 4
8.5031(8)
17.1626(13)
20.4991(19)
90
93.240(2)
90
fw
2716.91
Cc, 4
1345.71
P63mc, 6
18.6413(8)
18.6413(8)
12.9868(7)
90
90
120
3908.3(3)
19.316
3.431
space group, Z
a, Å
a, Å
P 3h c, 4
13.1066(3)
13.1066(3)
23.9243(11)
90
90
120
3559.2(2)
21.773
4.453
Fdd2, 16
25.626(9)
60.07(2)
15.614(5)
90
19.426(7)
19.031(6)
23.780(8)
102.885(8)
90
90
8570(5)
6.919
c, Å
R, deg
â, deg
γ, deg
V, Å
µ(Mo KR), mm
dcalc, g cm
90
90
3
24037(14)
19.696
4.184
2986.8(5)
20.799
3.888
-
1
-
3
2.106
2
θmax, deg
55
23 018
55
50
50
3891
65
24 062
0.051(12)
59
23 301
0.08(6)
no. of reflcns
Flack
final R1, wR2
30 466
0.011(10)
0.0544, 0.1173
23 748
0.025(11)
0.0637, 0.1343
0.0351, 0.0921
0.0423, 0.1112
0.0515, 0.1116 0.0615, 0.1212
a
[I > 2σ(I)]
a
R1 ) Σ||Fo| - |Fc||/Σ|Fo|; wR2 ) {Σ[w(Fo - Fc ) ]/Σ[w(Fo ) ]}1/2, w ) σF-2
2
2 2
2 2
.
based on the combination of æ- and ω-scans (graphite-monochro-
mated Mo KR radiation, λ ) 0.710 73 Å, 0.5° scan range, 5-30
s/frame). A hemispherical data set for 3 was collected at room
temperature on a three-cycle Bruker SMART CCD diffractometer
using the standard strategy (graphite-monochromated Mo KR
radiation, λ ) 0.710 73 Å, three ω-scans, starting ω ) -28°, φ )
2
heating W, Te, and I in a 1:2.4:1 molar ratio did react with
-
20
(
RO)
Directly substituting bromine for iodine in the syntheses does
not give a product which could serve as source of W Te in
the above-mentioned reactions (the only identified crystalline
2
PS
2
3 7 2 2 3
to give [W Te ((RO) PS ) ]I in a 6% yield.
3
7
2
1
material is the already known Te
reaction of WTe , Te, and Br in a 3:1:2 molar ratio at 390
C does give what we presume to be “W Te Br ”, on the
basis of its reaction with KCN solution, producing [W Te -
7 5
WOBr ). However,
0, 90, and 180°, detector at 2θ ) 28, 0.3° scan range, 20 s/frame).
2
2
The diffraction frames were integrated with subsequent constrained
cell refinement using the SAINT package and corrected for
absorption with SADABS.15 Further experimental details are
described in Table 1. Decomposition of the crystals did not occur
during data collection. The structures were solved by direct methods
and refined by full-matrix least-squares refinement on F2 in
anisotropic approximation for all non-hydrogen atoms (except for
°
3
7
4
3
7
2
-
(CN)
6
]
in a satisfactory yield.
3WTe + Te + 2Br f “W Te Br ”
2
2
3
7
4
-
2-
-
3
5
where C, N, and O atoms were left isotropic) using the SHELXTL
“W Te Br ” + 6CN f [W Te (CN) ] + 4Br
3 7 4 3 7 6
.10 software package.1 In 3 the positions of all hydrogen atoms
6,17
belonging to the PPh
4
groups were generated geometrically,
3 7
This result confirms that, just as in the case of W S and
assigned isotropic thermal parameters, and allowed to ride on their
respective parent carbon atoms. In the remaining structures,
hydrogen atoms of solvent water molecules were not located.
3 7 3 7
W Se cores, the W Te core can be assembled at moderate
temperatures (300-400 °C) in the halide environment. The
lack of single crystals prevents the structural elucidation of
11
Mo
3
Te
7
I
4
and W
3
Te
7 4
Br , but it is reasonable to suppose that
Results and Discussion
their structures are similar to their structurally characterized
analogues, Mo
2
2
M
3
Te
7
Clusters. Reactions of Mo, Te, and I
2
lead,
3
S
7
Cl
4 3 7 4
and W S Br .
depending on the reagents ratios, either to coordination
The reactivity of these telluride clusters is quite low, and
only very strong nucleophiles, such as CN , can overcome
18a
-
polymer Mo
3
Te
7
I
4
or to ionic compound [Mo
3
Te
7
(TeI
3
)
3
]I.
-
2-
In the latter the external ligands TeI
3
can be substituted by
their inertness, with [M
tungsten-containing cluster [W
this work for the first time, as Cs3.5K{[W
(CN) ]Br}Br1.5‚4.5H O (1, Figure 1) and Cs
(µ -Te (CN) Cl}Cl‚5H
3
Te
7
(CN)
6
]
as products. The
-
-
2-
2-
CN or (RO)
and [Mo Te ((RO)
was also claimed to take place by heating MoI
on the analytical characterization; no reactivity of that product
2
PS
2
(R ) Et, i-Pr) to give [Mo
3
Te
The formation of Mo
and Te, based
7
(CN)
6
]
3
Te
7
(CN)
6
]
was isolated in
-Te)(µ -Te
{[W (µ -Te)-
12,19
3
7
2 2
PS )
3
]I.
3
Te
7
I
4
3
(µ
3
2
2 3
) -
3
6
2
2
K
4
3
3
2
2
)
3
6
]
2
2
O (2, Figure 1S), after addition
1
8b
2-
was studied. Our initial attempts to prepare the tungsten
analogues under similar conditions failed, though recently
it was reported that an unidentified product obtained by
of various amounts of CsCl to the solution of [W
Compound 1 can be converted into (PPh {[W
Br}‚H O (3, Figure 2S) by cation exchange with Ph
3
Te
7
(CN)
(CN)
PBr.
6
] .
4
)
3
3
Te
7
6
]-
2
4
All these salts show the presence of a doubly charged anion
in the negative electrospray mass spectrum (ESI-MS) (cone
voltage 35 V) assigned to [W Te (CN) ] . Figure 2 shows
3 7 6
(
15) SADABS, version 2.11; Bruker Advanced X-ray Solutions: Madison,
WI, 2004.
2
-
(16) (a) Sheldrick, G. M. SHELX-97; Universit a¨ t G o¨ ttingen: G o¨ ttingen,
Germany, 1997.
(
(
17) Walker, N.; Stuart, D. Acta Crystallogr., Sect. A 1983, 39, 158.
18) (a) Fedin, V. P.; Imoto, H.; Saito, T. J. Chem. Soc., Chem. Commun.
(20) Chen, H.; Lin, X.; Chi, L.; Lu, C.; Zhuang, H.; Huang, J. Inorg. Chem.
Commun. 2000, 3, 331.
1
995, 34, 5097. (b) Evstafiev, V. K. Ph.D. Thesis, Nikolayev Institute
(21) Beck, J. Angew. Chem., Int. Ed. Engl. 1991, 30, 1128.
(22) (a) Cotton, F. A.; Kibala, P. A.; Matusz, M.; McCaleb, C. S.; Sandor,
R. B. W. Inorg. Chem. 1989, 28, 2623. (b) Marcoll, J.; Rabenau, A.;
Mootz, D.; Wunderlich, H. ReV. Chim. Miner. 1974, 11, 607.
of Inorganic Chemistry, Novosibirsk, Russia, 2004.
(
19) Lin, X.; Chen, H.-Y.; Chi, L.-S.; Zhuang, H.-H. Polyhedron 1999,
18, 217.
8118 Inorganic Chemistry, Vol. 44, No. 22, 2005

4+
3
W Te
7
Clusters
Figure 1. Molecular structure of [W3(µ3-Te)(µ2-Te2)3(CN)6]2- in 1 with
the atom-labeling scheme and 50%-probability thermal ellipsoids.
Figure 3. Molecular structure of [Mo3(µ3-Se)(µ2-Se2)3(CN)6]2- in 4 with
partial atom-labeling scheme and 50%-probability thermal ellipsoids.
Table 2. Reactions of M3Q7X4 with Molten KNCSe
reagent
final product
obsd intermediates
Mo3Te7I4 [Mo3Se7(CN)6]2 [Mo3Te4Se3(CN)6]2-
-
W3Te7Br4 [W3Se7(CN)6]2
- c
[W3Te4Se3(CN)6] , [W3Te3Se4(CN)6]
2- a
2-
,
W3Se5Te2(CN)6]2 , [W3Se6Te(CN)6]
-
2-
[
Mo3Se7Br4 [Mo3Se7(CN)6]2
W3Se7Br4 [W3Se4(CN)9]5
-
-
2-
[Mo3SSe6(CN)6]2-, [Mo3S4Se3(CN)6]2-
Mo3S7Br4 [Mo3Se7(CN)6]
- b
W3S7Br4
[W3S4(CN)9]5
a
Isolated. b Shorter reaction times. c Not isolated pure.
the solids in the KNCSe melt (200 °C). In no case NCSe-
complexes could be isolated; instead, chalcogen substitution
in the cluster core took place, with the formation of different
products depending on the starting cluster chalcogenide
Figure 2. ESI-MS spectra of the dianion [W3Te7(CN)6]2- in the negative
scan mode at 35 (top) and 55 V (bottom). The inset shows the observed
together with the simulated molecular peak using the natural isotope
abundance distribution.
(
Table 2). In the case of Mo
extraction with water, a dark red solution, from which red-
brown crystals of (NH {[Mo (µ -Se)(µ -Se (CN) ]I}-
O (4, Figure 3) were isolated. The NH
3 7 4
Te I we obtained, after
) K
4 1.5 3
3
3
2
2
)
3
6
+
I1.5‚4.5H
2
4
obviously
the mass spectrum recorded at 35 and 55 V. Increasing the
cone voltage up 50 V results in consecutive losses of three
-
comes from the partial decomposition of the NCSe . Thus,
complete exchange of the chalcogen in the cluster core takes
place under these reaction conditions.
tellurium atoms to give a species formulated as [W
3
Te
4
-
2-
(
CN) ] . Further increasing the cone voltage to 55 V result
6
in cyanide dissociation to afford the monoanionic species
Mo Te I + 7KCNSe f
3
7 4
-
[W
3
Te
4
(CN)
5
] .
K [Mo Se (CN) ] + 7Te + 4KI + KCN
2
3
7
6
2
-
2-
-
[
W Te (CN) ]
8 [W Te (CN) ]
-Te8
It must be stressed that the complex [Mo
not available by direct reaction of polymeric Mo
3
Se
7
(CN)
Se Br
6
]2 is
3
7
6
3
6
6
-
Te
2-
2-
3
7
4
with
[
W Te (CN) ]
8 [W Te (CN) ]
-CN8
3
5
6
3
4
6
-Te
KCN (in contrast to the telluride), which instead gives
-
5-
[W Te (CN) ]
[Mo
3
Se
4
(CN)
9
]
after Se abstraction from the three Se
2
3
4
5
2
4
bridging ligands.
In the case of 2, low-intensity peaks due to ionic associates
Cs[W Te (CN) ]} and {Cs[W Te (CN) ]} were also
3 7 6 3 5 6
Mo Se Br + 12KCN f
-
-
3
7
4
{
K [Mo Se (CN) ] + 3KCNSe + 4KBr
observed. A similar fragmentation pattern of consecutive
chalcogen loss has been reported for related sulfur- and
selenium-containing complexes Mo
5
3
4
9
-
[
Mo
3
Se
4
(CN)
9
]5 is quantitatively obtained in reaction of
4+
3
Q
7
(Q ) S, Se) using
2
-
-
[
Mo
3
Se
7
(CN)
6
]
with free CN in aqueous solution:
FAB or L-SIMS mass spectrometry, where stepwise abstrac-
tion of three chalcogen and ligand dissociation of one
2-
-
5-
-
[
Mo Se (CN) ] + 6CN f [Mo Se (CN) ] + 3CNSe
23
3 7 6 3 4 9
bidentate outer ligand are observed.
-
The coordinated CN ligand is observed in the IR
Molten KNCSe is in equilibrium with KCN and Se. To
explain why the CN present in the KCNSe melt failed to
-
1
spectrum as intense bands at 2088 cm (1) and 2091 and
-
-
1
-1
2
061 cm (2), which are comparable with 2100 cm for
2-
5-
convert [Mo
3
Se
7
(CN)
6
]
into [Mo
3 4 9
Se (CN) ]
the following
2-
[Mo
3
Te
7
(CN)
6
]
2 3 7 6
in the double salt Cs2.5K {[Mo Te (CN) ]I}-
equilibrium must be considered:
1
2
I
1.5‚3H
2
O.
Reactions with KNCSe Melt. Our original idea was to
use low-melting KNCSe to effectuate ligand substitution in
polymeric M Te and their S and Se analogues, by heating
4
+
-
4+
-
Mo Se + 3CN ) Mo Se + 3NCSe
3
7
3
4
3
I
7 4
The equilibrium is shifted to the right in the reaction between
(
23) Hegetschweiler, K.; Caravatti, P.; Fedin, V. P.; Sokolov, M. N. HelV.
(24) Fedin, V. P.; Lamprecht, G. J.; Kohzuma, T.; Clegg, W.; Elsegood,
Chim. Acta 1992, 75, 1659.
M. R. J.; Sykes, A. G. J. Chem. Soc., Dalton Trans. 1997, 1747.
Inorganic Chemistry, Vol. 44, No. 22, 2005 8119

Sokolov et al.
Scheme 1
Mo
3
Se
7
Br
4
with aqueous solution of KCN, in which an
6 2
(CN) ]Br}‚6H O (5, Figure 4). The Se atoms selectively enter
excess of KCN was used, and to the left in the melt, where
2 2
into the equatorial positions of the µ -Q ligands, thus giving
2-
KNCSe is in excess. The compatibility of Se
2
(as reaction
access to previously practically unknown complexes of
-
2-
product) with CN (as reagent) is corroborated by the
SeTe , which can be regarded as a new inorganic ligand.
preparation of Se
[Re Se10(CN) ] in the reaction of ReSe
C. That the real reaction takes place stepwise can be seen
from ESI-MS of the crude products, which shows not only
2
-bridged chain of {Re
6
Se
8
(CN)
4
} units in
The only other example of a SeTe complex is found in [Fe
2
-
K
°
6
6
4
2
with KCN at 650
(µ-SeTe)(CO) ] which can be prepared “in pure form and
6
25
in good yields”, but the characterization is based solely upon
chromactographic behavior, reactivity, and IR in the CO
2-
28
dominant peaks of [Mo
peak due to [Mo Te Se
Se exchange occurs as regioselective as the S/Se one, the
Se atoms must occupy the equatorial positions of the M
3
Se
7
(CN)
6
-
]
but also another (minor)
region. Another well-defined mixed Se/Te ligand, open-
2
2-
3
4
3
(CN)
6
] . If we assume that the Te/
chained [Se-Te-Te-Se] , is obtained by selective sub-
2
6
2-
stitution of the central Se atoms in [Hg(Se
4
)
2
]
(those not
3
-
bound with Hg) with Et
lective.
3
PTe. This reaction is also regiose-
4+
29
(µ
3
-Q)(µ-Qax.-Qeq.
)
3
core. The reaction of Mo
3
Se
7
Br
4
with
molten KCNSe is a more direct and clean way to [Mo
3
-
-
2
-
Se
Se
7
7
(CN)
Br
6
] . Thus, under these conditions, 1.00 g of Mo
(0.86 mmol) and 1.50 g of KCNSe (10.41 mmol)
3
4
give 0.34 g of the red-brown microcrystalline product
2
-
4+
([Mo
3
Se
7
(CN)
6
]
3 7
was detected by ESI-MS). The Mo S
clusters in solution undergo regiospecific Se for S substitution
4
+
into the equatorial positions, leading to the Mo
3 4 3
S Se
clusters, as can be illustrated by the synthesis of [Mo
3 4
S -
+
+
Se
CH
KCNSe melt at 200-220 °C the chalcogen exchange pro-
3
(Et
2 2 3 3 7 2 2 3
NCS ) ] from [Mo S (Et NCS ) ] and KNCSe in
Figure 4. Molecular structure of [W3(µ3-Te)(µ2-SeTe)3(CN)6]2 in 5 with
-
26
3
CN solution, already at room temperature. In the
partial atom-labeling scheme and 50%-probability thermal ellipsoids.
2
-
2-
gresses further, with [Mo
as intermediates (detected by ESI-MS) and [Mo
as the final product. From the stoichiometry we may assume
3
S
4
Se
3
(CN)
6
]
and [Mo
3
SSe
6
(CN)
(CN)
6
]
]
In fact the reaction proceeds stepwise, and the monitoring
by ESI-MS shows the sequential formation of [W Se Te -
2-
3
Se
7
6
3
3
4
2
-
2-
(CN)6] (m/z ) 728), [W Se Te (CN) ] (m/z ) 704),
3
4
3
6
2-
2-
2-
that the intermediate [Mo
in the capping (µ ) position. Thus, the relative lability of
chalcogen atoms in the three different positions of M (µ
3
SSe
6
(CN)
6
]
still retains sulfur
[W Se Te (CN) ] (m/z ) 680), [W Se Te(CN) ] (m/z )
3
5
2
6
3
6
6
2
-
3
656), and [W Se (CN) ] (m/z ) 632). The proposed
3
7
6
3
3
-
sequence is shown in Scheme 1. The latter complex is not
particularly stable under the reaction conditions, and the
reaction between W Se Br and KNCSe always yields
4+
Q)(µ-Qax.-Qeq.
)
3
cores is Qeq > Qax > µ
The only other example of the replacement of bridging
Te by Se is the transformation of tetrahedral cluster [Re
3
-Q.
3
7
4
5
-
4
-
3 4 9
[W Se (CN) ] .
4-
4+
Te
in superheated CH
Reaction of “W Te
isolation of a mixed Se/Te cluster, K
4
(TeCl
2
)
4
Cl
8
] into octahedral [Re
CN at 200 °C.27
Br ” with KNCSe in melt allowed the
{[W (µ -Te)(µ -SeTe)
6
Se
8
(CN)
6
]
by KNCSe
3
The tungsten clusters show a lesser stability of the W Q7
3
core, which more or less easily loses three chalcogen atoms
4
+
3
7
4
of µ -Q ligands, giving more stable W Q
2
2
3
4
clusters. For
2
-
5-
3
3
3
2
3
-
3 7 6 3 4 9
example, [W S Br ] gives [W S (NCS) ] already by
1
1b
heating with KNCS in acetonitrile solution.
surprise, then, that the tungsten clusters W Se Br
It is no
3 7
and W S -
(
(
(
25) Mironov, Y. V.; Fedorov, V. E.; McLauchlan, C. C.; Ibers, J. A. Inorg.
3
7
4
Chem. 2000, 39, 1809.
26) Fedin, V. P.; Sokolov, M. N.; Virovets A. V.; Podberezskaya N. V.;
Fedorov, V. Ye. Polyhedron 1992, 11, 2395.
(28) Mathur, P.; Chakrabarty, D.; Munkir Hossain, Md. J. Organomet.
Chem. 1991, 401, 167.
27) Eanes, M. E.; Ibers, J. A. Inorg. Chem. 2002, 41, 6170.
8120 Inorganic Chemistry, Vol. 44, No. 22, 2005

4+
3
W Te
7
Clusters
Table 3. Selected Bond Lengths (Å) for 1-6
param
M-M
1
2
3
4
5
6
2.87
2.71
2.86-2.89
2.71-2.73
2.80-2.85
2.74-2.77
2.06-2.18
1.59-2.25
2.68-2.70
2.88
2.78
2.54
2.61-2.62
2.56
2.17
2.82-2.83
2.71
2.82-2.86
2.67-2.69
M-µ3-Q
M-Qeq
2.70-2.71
2.80-2.82
2.74-2.76
2.11-2.21
2.12-2.20
2.68
2.81-2.82
2.74-2.76
2.16
2.64-2.65
2.72-2.74
2.13-2.19
2.10-2.16
2.50-2.52
M-Qax
2.43-2.47
2.05-2.37
1.96-2.30
a
M-Ctrans
b
M-Ccis
2.12
2.15
2.35
Qeq-Qax
2.69
a
M-Ctrans distance trans to M-µ3-Q bond. b M-Ccis distance cis to M-µ3-Q bond.
Br
4
give only the chalcogen-poor incomplete cuboidal
5-
clusters under similar conditions: [W
3
Se
4
(CN)
9
]
in the first
[W
] (Q ) S, 7; Q ) Se, 8) can be isolated by adding a
5-
case and [W
CN)
3 4
S (CN)
9
]
in the second case. Pure K
5
3 4
Q -
(
9
large volume of THF to the aqueous extracts after melting
and cooling. The ESI-MS spectra of 7 and 8 show the peaks
2
-
-
of [W
able parent [W
excess of negative charge carried by the 5- anions
3
Q
4
(CN)
6
]
(from the loss of three CN by unobserv-
5-
2-
3
Q
4
(CN)
9
] ) and of [W
3
Q
3
(CN)
6
] . The
Figure 5. Molecular structure of [W3(µ3-Te)(µ2-Se)3(CN)9]5- in 6 with
partial atom-labeling scheme and 50%-probability thermal ellipsoids.
5-
3 4 9
[W Q (CN) ]
prevents its appearance in the gas phase, and
only the more stable ligand dissociation products, i.e.,
dianions, are observed.
The electronic spectra are characteristic and correspond
exchange show the unexpected preparation of a W
3
(µ
)] (dtp )
7
, PAB ) para-aminobenzoate), from [Mo Te -
3
-S)-
4
+
(µ-Te)
(i-PrO)
3
3 3 3 3
cluster, [Mo STe (dtp) (PAB)(PBu
2
PS
2
3
5
-
to that reported for the [W
Br and aqueous solution of KCN. The Se NMR
spectrum of [W
two signals at 1666.1 and 1133.5 ppm. In [W
3
Q
4
(CN)
9
]
species prepared from
3
(dtp) ]I. The sulfur atom comes from the dithiophosphate
24
77
34
W
Q
3 7
4
ligand.
Crystal Structures. Crystal structures were determined
for Cs3.5K{[W (µ -Te)(µ -Te (CN) ]Br}Br1.5‚4.5H O (1),
Cs {[W (µ -Te)(µ -Te (CN) Cl}Cl‚5H O (2), (Ph P)
{[W Te (CN) ]Br}‚H O (3), (NH {[Mo Se (CN) ]I}-
O (4), K {[W (µ -Te)(µ -SeTe) (CN) ]Br}‚6H
(5), and K [W (µ -Te)(µ -Se)
geometrical parameters of [M
5-
3 3
(µ -Se)(µ
2
-Se)
3
(CN)
9
]
shows, as expected,
(µ -Se)
-Se is observed at 1496 ppm.
KNCS in melt under similar conditions converts W Br
(via intermediate species
4
3
4
30
-
3
3
2
2
)
3
6
2
6-
(
CN)12
]
the signal from µ
3
K
2 4
3
3
2
)
2 3
]
6 2
2
4
3
-
3
S
7
4
3
7
6
2
4
2
)
1.5
K
3
3
7
6
5-
and W
3
Se
7
Br
4
into [W
3
-31
S
4
9
(NCS) ]
I
1.5‚4.5H
2
3
3
3
3
6
2
O
5
-
[W
3
S
x
-
Se4-x(NCS)
9
]).
The NCS ion is more stable than
5
3
3
2
3
(CN)
9
] (6). The observed
-
2-
NCSe , and no formation of the competing CN takes place
3
Q
7
(CN)
6
]
are summarized
under the experimental conditions.
In the reactions studied in this work, the M
is preserved. It is thus stable in the presence of QCN /CN
at least up to 220 °C. Raising the temperature up to 450 °C
in Table 3. In all cases these anions are heavily involved in
secondary (specific nonbonding) interactions with the halide
IV
3
triangle unit
-
-
-
mainly through 3Qax‚‚‚X contacts, which are sometimes
-
supported by Qeq‚‚‚X or by Qeq‚‚‚Qeq. interactions. As in
4
+
4+
does lead to reduction and transformation into cuboidal
the case of M
S
3 7
3
and M Se
7
clusters, these contacts are
III
IV
30
clusters with tetrahedral M
2 2
M cores. Even more drastic
much shorter then the sum of van der Waals radii of
3
5,36
conditions (650 °C) would possibly favor the formation of
corresponding elements.
Thus {anion + anion} aggre-
6
-/7-
32
3-
3-
even more reduced [Mo
6
Q
8
(CN)
Cluster. By adding KCN to the
extract from the reaction of W Te Br with KNCSe, we
complex, K [W (µ -Te)(µ
6
]
clusters.
gates {[W
3
3-
Te
7
(CN)
6
]Cl} , {[W
3 7 6 3 7
Te (CN) ]Br} , {[Mo Se -
4+
3-
W
3
(µ
3
-Te)(µ-Se)
3
(CN)
6
]I} , and {[W
3
Te Se (CN) ]Br} form via three
symmetrically equivalent Teax‚‚‚Br contacts (3.420(2) Å)
for 1, three Teax‚‚‚Cl contacts (3.152(9)-3.276(9) Å) for
2, three Teax‚‚‚Br contacts (3.198(4)-3.304(3) Å) for 3,
three symmetrically equivalent Seax‚‚‚I contacts (3.446(1)
Å) for 4, and three nonequivalent Teax‚‚‚Br contacts for 5
4
3
6
-
3
7
4
4+
-
obtained a W
3
(µ
3
-Te)(µ-Se)
3
5
3
3
2
-
-
Se)
in [W
3
(CN)
9
] (6, Figure 5). The attack takes place either at Te
2-
-
-
3
Se
3
Te
4
(CN)
6
]
(TeCN initially formed is unstable
-
-
in aqueous solution and decomposes into CN and Te; the
precipitation of the latter was observed) or at Se in
(3.067(2)-3.236(3) Å, Figure 6). It should be noted that the
length of Qax‚‚‚X contacts does not exclusively depend on
the nature of Q and X. Indeed, the van der Waals radii of X
2-
[W
3
Se
6 6
Te(CN) ] . Also, it is not possible to exclude the
initial attack on Se with subsequent Se/Te interchange with
-
4+
-
-
SeCN . The M
Q
3 4
cores are susceptible to chalcogen
vary from 1.80 Å for Cl to 2.15 Å for I (in the Pauling
35
system ). It means that if we assume the “usual”, nonspecific
(
29) Bollinger, J. C.; Ibers, J. A. Inorg. Chem. 1995, 34, 1859.
nature of Q‚‚‚X interaction the Te‚‚‚I distance should be at
(
30) Fedin, V. P.; Kalinina, I. V.; Samsonenko, D. G.; Mironov, Y. V.;
Sokolov, M. N.; Tkachev, S. V.; Virovets, A. V.; Podberezskaya, N.
V.; Elsegood, M. R. J.; Clegg, W.; Sykes, A. G. Inorg. Chem. 1999,
(33) Saysell, D.; Fedin, V. P.; Lamprecht, G. J.; Sokolov, M. N.; Sykes,
A. G. Inorg. Chem. 1997, 36, 2982.
38, 1956.
(31) Fedorov, V. E.; M uˆ ller, A.; Fedin, V. P.; Sokolov, M. N. Zh. Neorg.
Khim. 1994, 39, 1663.
(34) Lin, X.; Chen, H.-Y.; Chi, L.-S.; Lu, C.-Zh.; Zhuang, H.-H. Polyhedron
2000, 19, 925.
(
32) (a) Mironov, Y. V.; Virovets, A. V.; Naumov, N. G.; Ikorski, V. N.;
Fedorov, V. E. Chem.sEur. J. 2000, 6, 1361. (b) Magliocchi, C.; Xie,
X.; Hughbanks, T. Inorg. Chem. 2000, 39, 5000.
(35) Batsanov, S. S. Russ. J. Inorg. Chem. 1991, 36, 1694.
(36) Virovets, A. V.; Podberezskaya, N. V. Zh. Struct. Khim. 1993, 34,
150.
Inorganic Chemistry, Vol. 44, No. 22, 2005 8121

Sokolov et al.
Figure 6. Structure of the adduct {[W3Te4Se3(CN)6]Br}3- in 5.
Table 4. Interatomic Distances d(Qax‚‚‚X) and Covalence Indices fcov
a
3-
for the QAx‚‚‚X Interactions in the {[M3Q7(CN)6]X} Adducts
formula
d(Qax‚‚‚X), Å
fcov
ref
1
2
3
4
5
3.42
0.41
0.49
0.55
0.42
0.63
0.45
this work
this work
this work
this work
this work
12a
3.15-3.28
3.20-3.30
3.45-3.49
3.07-3.24
3.58
Cs4.5[Mo3Te7(CN)6]I2.5‚3H2O
a
fcov ) [RvdW(Q) + RvdW(X) - d(Qax-X)][RvdW(Q) + RvdW(X) -
-
1
Rcov(Q) - Rcov(X)] , where RvdW and Rcov are the van der Waals radii and
covalent radii of the corresponding atoms.
least by 0.35 Å longer than Teax‚‚‚Cl one. In reality, this
difference is only about 0.25 Å (3.45 Å in 4 vs. 3.20 Å in
Figure 7. Fragment of the crystal structure of 2. Key: black circles, W;
medium gray, Te; light gray, Cl, C, N. Other atoms are omitted for clarity.
The Te‚‚‚Cl and Te‚‚‚N contacts are shown as dashed lines.
2). In the same time, average the Teax‚‚‚Br distance in 5 is
only 3.15 Å, even shorter then Teax‚‚‚Cl in 2! It confirms
the specific nature of 3 Teax‚‚‚X interactions,3
2,33,36
which
long Teeq‚‚‚Cl contact of 3.886(8) Å corresponding to an
additional, weaker interaction. These contacts together with
alkaline metal cations combine the chains into a 3D
framework.
In the crystal structure of 5 there are linear chains running
along the x axis. The bromine anions form three contacts
become increasingly important in the order Cl < Br < I.
To analyze such contacts, a semiempirical parameter, the
covalence factor (fcov), was found to be useful (Table 4).
f
cov ) 0 corresponds to no bonding, and fcov ) 1, to normal
35-37
covalent bonding.
observed for {[M
The contacts of about 3.1-3.6 Å
-
3
Q
7
(CN)
6
]X}3 represent a significant
with 3 Teax and one additional short contact of 3.205(2) Å
degree of bonding (fcov ) 0.4-0.6).
-
with Seeq of the neighboring {[W
3
Te
4
Se
3
(CN)
6
]Br}3 ag-
The specific interactions with Se and Te atoms of the
gregate.
4+
M
3
Q
7
cluster core play the key role in the formation of
Another interesting packing motif can be seen in 1 and 4,
crystal packings of 1-5. The most interesting case here is
3-
3-
3 7 6 3 7 6
where the {[W Te (CN) ]Br} and {[Mo Se (CN) ]I}
2
, where the relatively small cluster anions (the longest
aggregates are bound into corrugated layers running parallel
2-
dimension in [W
3
Te
7
(CN)
6
]
is in the N‚‚‚Teeq direction
-
to ab plane via linear, symmetrical Teeq‚‚‚Br ‚‚‚Teeq and
+
+
-
(8.1 Å), small Cs , K , and Cl , and water molecules
-
Seeq‚‚‚I ‚‚‚Seeq contacts of 3.3405(7) and 3.489(1) Å,
generate fantastically complicated packing with quite rare
Fdd2 space symmetry, 16 formula units/unit cell, and one
of the cell parameters, b, about 60 Å. The reason is the
presence of various types of specific interactions. In this
structure there are two crystallographically independent
respectively, with the participation of extra halogen anions
(
K
Figure 8). The compounds 1 and 4 are isostructural with
(µ -Te)(µ -Te (CN)
-Te (CN)
(CN)
4.5{[Mo
3
3
2
2
)
3
6
]I}I1.5‚3H
2 3
O, Cs2.29K2.21{[Mo -
(
(
µ
3
-Te)(µ
-Te
2
2
)
3
6
]I}I1.5‚3H
]I}I1.5‚3H
2
O, and Cs4.5{[Mo
3
3
(µ -Te)-
O.12
µ
2
2
)
3
6
2
cluster anions with different structural roles. One of them
The geometrical parameters of the cluster cores in 1-6
-
forms a {[W
3
Te
7
(CN)
6
]Cl}3 aggregate with 3 Teax‚‚‚Cl
are strongly dependent on the bridging chalcogen (Table 3).
While changes from Mo to W and in the nonbridging ligands
hardly influence the M-M bond lengths (for example, the
contacts (see above). Then, one of its CN groups make three
short Teax‚‚‚N contacts of 2.87(2), 2.95(2), and 3.30(2) Å
with another cluster anion resulting in zigzag chains. There
are also two short contacts Teeq‚‚‚N (2.97(3), 3.38(3) Å)
between two neighboring clusters, which also participate in
the chain formation (Figure 7). Therefore, all atoms Teax are
involved in specific interactions with chlorine anions and
nitrogen atoms of the CN ligands. In addition, there is a quite
Mo-Mo distances are in Cs4.5{[Mo
3
(µ
((EtO)
2 3
) ]I 2.84-2.85 Å, in 1 and 2
3
-Te)(µ
2
-Te
2 3 6
) (CN) ]I}-
12
I
1.5‚3H
2
O 2.891(2) Å, in [Mo
Te
3 7
2
PS
2 3
)
]I 2.89-2.90
19
20
Å, in [W
3
Te ((EtO) PS
7
2
2
.86-2.89 Å, and in 3 2.88 Å), the change from Te to Se
decreases the M-M distances by about 0.1 Å (the Mo-Mo
distance in 4 is 2.78 Å). As can be expected, the effect of
2-
the mixed ligand TeSe is intermediate (the W-W distances
are 2.82-2.83 Å in 5). The order of M-Te bond lengths is
(
37) Mayor-Lopez, M.; Weber, M.; Hegetschweiler; K.; Meienberger, M.
D.; Jobo, F.; Leoni, S.; Nesper, R.; Reiss, G. J.; Frank W.; Kolesov,
B.; Fedin, V.; Fedorov, V. Inorg. Chem. 1998, 37, 2633.
M-µ -Te < M-Teax < M-Teeq, spanning the range of more
3
8122 Inorganic Chemistry, Vol. 44, No. 22, 2005

4+
3
W Te
7
Clusters
Figure 9. Fragment of crystal structure of 6. The Seax‚‚‚Te contacts of
.603(7) Å are shown as dashed lines.
3
crypt)]
2
TeSe
2
‚en and in [Mn(en)
3 2
]TeSe (2.50 Å) (formally
a single bond), and is expectedly longer than 2.46-2.47 Å
in [K(2,2,2-crypt)]
2
TeSe
3
‚en (formal bond order 4/3 in the
2
-).43
pyramidal TeSe
3
]5 in 6 is shown in Figure
-
The structure of [W
3
TeSe
3
(CN)
9
5
2
. The W-W distances are 2.82-2.86 Å, W-Se are 2.43-
.47 Å, and W-Te are 2.67-2.69 Å. Closely related
Figure 8. Fragment of crystal structure of 4, view along the b axis. Key:
black circles, Mo; medium gray, Se; light gray, I. Other atoms are omitted
for clarity. The Se‚‚‚I contacts are shown as dashed lines.
5
-
[
W
3
Se
in the µ
CN) ]‚CsCl‚4H
distances: W-W, 2.829 Å; W-Se, 2.449 Å; W-(µ
4
(CN)
position, is found in the double salt Cs
O and has the following (mean) interatomic
-Se),
.497 Å. It is immediately apparent that this change from
9
] , which differs only by the presence of Se
3
5
[W Se
3
4
-
(
9
2
than 0.1 Å, and the absolute values are close to those for
3
clusters.1
8-20
The same sequence was found for
other M
3
Te
7
24
2
W
38
the Mo-Se bonds in 4. In the chalcogen-mixed cluster 5,
the W-Seeq distances are close to those found in the W
4+
4+
3
Se
4
to W
3
TeSe
3
does not affect (geometrically) the
-Te bond in 6 is somewhat
3
-
rest of the cluster. The W-µ
shorter than in the heptachalcogenide clusters in 1-3 and 5.
In the crystal the anions [W
the same direction (“face-to-tail”) and stack to form the
columns running along the c axis. Within the columns, three
short Te‚‚‚Se contacts (3.603(7) Å) form between neighbors
3
4
+
+
Se
PS
range observed in 1-3 and in [W
7
clusters, such as [W
3
Se
7 2 2 3 3 7 2
(Et NCS ) ] and [W Se ((EtO) -
+
39
2
)
3
] , and the W-Te distances are roughly inside the
5-
3
TeSe
3
(CN)
9
]
are oriented in
2
0
3
7 2 2 3
Te ((EtO) PS ) ]I. This
shows that the M-M interactions are more flexible than the
M-Q ones and adapt themselves to the sterical constraints
imposed on the molecular architecture by the chalcogen size.
There are two other types of W/Te clusters, where all the
(Figure 9). The intercolumnar space is filled with potassium
cations which interact with nitrogen atoms of the cyanide
ligands (2.6-3.0 Å). Such a packing motif is new for M Q
3 4
clusters but can be seen in some M
6
-
Te atoms are of µ
(
3
type: the cuboidal clusters [W
4
Te
W-Te, 2.69 Å; W-W, 2.86 Å) and the octahedral clusters
Te ] (L ) PEt , py, piperidine) (W-Te, 2.74-2.76
4
(CN)12
]
4+
30
4+
Q
3 7
4 2
ones, e.g. in (NH ) -
[W
6
8
L
6
3
44
[Mo (S ] (Sax‚‚‚µ
S
3 7
)
2 3
3
-S are of 3.02 Å). This way of packing
40
Å; W-W, 2.73-2.77 Å). The Te-Te bonds are by 0.10-
is radically different from what is observed in the structures
0
.15 Å shorter than in elemental tellurium (2.835 Å). This
24
of Cs
SO
cluster anions are weakly dimerized through “face-to-face”
-Se‚‚‚µ -Se interactions.
The importance of specific interactions between heavier
5
[W
‚12H
3
Se
4
(CN)
9
]‚CsCl‚4H
2
O, [W
3
Se
4 2 9 3 6 4
(H O) ](p-CH C H -
4
+
difference is somewhat intriguing, since in the M
M
lengths as in elemental chalcogens (2.05-2.08 Å in S
3
S
7
and
45
11
3
)
4
2
O, and (Me NH)
3
5
[W Se
3
4
(NCS) ], where the
9
4
+
3
Se
7
cores the S-S and Se-Se bonds have the same
, 2.30-
[Te ] and
], the Te-Te bond lengths are 2.737(1)
8
µ
2
2
4
1
(
[
1) Å in gray Se). On the other hand, in [Me
Na(CH OH) [Te
4
N]
2
2
3
3
]
2
2
nonmetals is increasingly being recognized. In addition to
halogen-halogen, chalcogen-chalcogen, and pnictogen-
pnictogen interactions
classical H-bonding and π-π stacking), the chalcogen-
42
2-
2
and 2.744(1) Å, respectively. In both complexes the [Te ]
dumbbells are well separated and do not interact. The Te-
Se bond distance in 5, 2.50-2.52 Å, has the same value as
4
6-48
(and, of course, to the already
2-
in the V-shaped anion [SeTeSe] , present in [K(2,2,2-
halogen contacts must be added to the list of noncovalent
(
38) Sokolov, M. N.; Gushchin, A. L.; Naumov, D. Yu.; Gerasko, O. A.;
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Sawyer, J. F.; Schrobilgen, G. J. Inorg. Chem. 1991, 30, 4238.
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Kirschner, R. M. Z. Naturforsch. 1979, B34, 434.
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(
b) Fedin, V. P.; Sokolov, M. N.; Gerasko, O. A.; Virovets, A. V.;
Podberezskaya, N. V.; Fedorov, V. Ye. Inorg. Chim. Acta 1991, 187,
1.
8
(
40) Xie, X.; McCarley, R. E. Inorg. Chem. 1997, 36, 4665.
(45) Hernandez-Molina, R.; Elsegood, M. R. J.; Clegg, W.; Sykes, A. G.
J. Chem. Soc., Dalton Trans. 2001, 2173.
(41) (a) Templeton, L. K.; Templeton, D. H.; Zalkin, A. Inorg. Chem. 1976,
1
1
5, 1999-2001. (b) Avilov, A. S.; Imanov, R. M. Kristallografiya
(46) Pedireddi, V. R.; Reddy, D. S.; Goud, B. S.; Craig, D. C.; Rae, A. D.;
Desiraju, G. R. J. Chem. Soc., Perkin Trans. 2 1994, 2353.
(47) Gleiter, R.; Werz, D.; Rausch, B. Chem.sEur. J. 2003, 9, 2677.
(48) UnkoVentionelle Wechselwirkungen in der Chemie Metallischer
Elemente; Forschungsbericht DFG; Krebs, B., Ed.; VCH: Weinheim,
Germany, 1992.
969, 14, 230.
(
42) (a) Batchelor, R. J.; Einstein, F. W. B.; Gay, I. D.; Jones, C. H. W.;
Sharma, R. D. Inorg. Chem. 1993, 32, 4378. (b) Thiele, K.-H.;.
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1996, 622, 231.
Inorganic Chemistry, Vol. 44, No. 22, 2005 8123

Sokolov et al.
interactions essential for specific packing and supramolecular
aggregation.
(Grant 2356), Russian Foundation for Basic Research (Grant
05-03-32126), and Haldor Topsøe Foundation (to A.L.G.).
Supporting Information Available: CIF files for the structures
-6 and atom labeling schemes for 2 and 3. This material is
available free of charge via the Internet at http://pubs.acs.org.
Acknowledgment. Grants to M.N.S. of the Russian
Science Support Foundation and of the Bancaixa-Universitat
Jaume I Foundation (Ref P1 1B2004-19) are gratefully
acknowledged. The work was supported by the INTAS
1
IC050962C
8124 Inorganic Chemistry, Vol. 44, No. 22, 2005