Full text of DOI:10.1016/S0020-1693(00)90158-0

182 (1991) 221-228
221
Heterobimetallic aggregates derived from the double cubane-like
structure
(M = MO, W)
Francis
Francis Robert,
Manak
Laboratoire de Chimie des
75252 05 (France)
de Transition UA-CNRS 419,
Pierre et Marie Curie, 4 Place
J ean-Marie Manoli and Claude P otvin
Laboratoire de
de Surface et Structure, UA-CNRS 1106,
Pierre et Marie Curie, 4 Place Jussieu,
75252 Paris Ceder 05 (France)
(Received July 1, 1990; revised November 5, 1990)
Abstract
Nucleophilic substitutions in the double cubane-like structures
(M = MO, W) are
complicated by elimination reactions. With
anion whereas a face-elimination by
by bipyridine produced the lacunary
by X-ray diffraction studies.
an edge-elimination process gave the
led to the monocubane structure
Substitution
The different species were characterized
Introduction
The tetrathiometallates
known to act as multidentate ligands to a wide variety
of transition metal ions Among these compounds
only examples of double cubane-like structures
have been and
W) are
A perspective view of the recently prepared
molybdenum dicubane, shown in Fig. 1, confirms the
open 12-atom cage.
probably owing to the missing
is reactive,
and
edges which make the close approach
of nucleophilic reagents to the terminal
groups
or to the facial chloro bridges easier. Four active
nucleophilic reagents were tested in this work: (i)
the monodentate
bidentate
and
ligands, (ii) the
(bipy) and
Fig. 1. Perspective view of the
anion
throline (phen).
showing the atom labelling scheme. Half of the anion
(primed atoms) is generated through a binary axis passing
through
and
Experimental
the Service Central
du CNRS. Infrared
spectra were recorded on a Perkin-Elmer 580 B
spectrophotometer. UV-Vis spectra were obtained
with a Uvikon 810 spectrophotometer.
Preparations of compounds
The complexes prepared here are air- and mois-
ture-stable. Solvents and chemicals were used as
purchased. Chemical analyses were performed by
This preparation completes our studies on the
synthesis of double cubane-like structures
The
*Author to whom correspondence should be addressed.
Elsevier Sequoia/Printed in Switzerland

222
route described here allows molybdenum dicubane
as crystals of fair diffraction quality to be obtained.
X-ray data collection and reduction
Suitable crystals of
and 3 were selected directly
To a suspension of 0.093 g of
mmol) in 25 ml of
(0.25
from the preparations. Diffraction studies were per-
formed at room temperature on a Nonius CAD4
four-circle automated diffractometer with graphite
was added aerobically
0.075 g of
mmol). The mixture was stirred
for 30 min and then filtered. The filtrate was kept
at room temperature for 24 h. The violet crystals
obtained were collected and washed with 20 ml of
ether. The composition of 1 was established by IR
and UV-Vis methods by comparison with the spectra
monochromated MO
radiation and a
scan
technique. The orientation matrix and unit cell pa-
rameters were determined by least-squares treatment
of 25 machine-centered reflections. The intensities
of three standard reflections were measured every
100 reflections and revealed no significant decay in
intensities. The intensities were corrected for po-
larization and Lorentz effects. An empirical ab-
sorption correction based on azimuthal scan mea-
surements was applied. Details concerning the
intensity and data collection are given in Table 1.
of the homologous
and
by single X-ray analysis.
A solution of 0.090 g of bipyridine (bipy) (0.25
mmol) in 15 ml of acetonitrile was added to a solution
of 0.059 g of
in 60 ml of
Structure solution and refinement
Computations were performed by using SHELX76
acetonitrile. After storage for 8 hat room temperature
the solution afforded red crystals which were collected
and washed with ether. Electronic spectra: 432,
nm, slightly soluble. IR spectra: 505,
for 1 and 3 and CRYSTALS
programs for
2. Heavy-atom positions were obtained by the Pat-
terson method. All remaining non-hydrogen atoms
were located from successive least-squares refine-
ments and difference Fourier maps. Anisotropic ther-
mal parameters were introduced for MO, W, Cu, S,
P, N and C atoms. Final R factors are given in Table
1. Individual structural refinements are given for 2.
470, 438 cm-’
The homologous MO com-
pound (2’) was similarly obtained from 0.055 g of
The composition and crystal structure of 2 were
established by single-crystal X-ray analysis.
Addition of five equiv. of
viously dissolved in
pre-
to a solution of tungsten
isolated
dicubane led after c. 24 h to
as orange needles and identified by IR and UV-Vis
spectra
Results and discussion
Crystal structure of 1
The structure determination confirms that 1 is
isostructural to
compounds the heavy metal
(3)
Compound 3 was obtained in this work as the
product of the reaction of a solution of 0.040 g of
In both
and a
(0.15 mmol) in 15 ml of
with 0.059 g
group lie on the binary axis that generates a similar
of
previously dissolved in
Storage for 24 h at room temperature
open
cage as shown in Fig. 1. The geometry
is nearly tetrahedral, see Table
groups are bound to the
through double bridged
tetrahedron
60 ml of
about the
2. Five
(Cu-S
afforded 0.040 g of yellow crystals.
C, 49.23; H, 3.51;
6.81; Cl, 2.60; Cu, 13.96; W, 13.47. Found: C, 48.89;
H, 3.31; S, 9.80; P, 7.02; Cl, 2.98; Cu, 14.42; W,
13.95%. The unsolvated species was prepared directly
for
9.38; P,
core
copper atoms, the sixth edge of the
remaining uncoordinated. The overall geometry can
be viewed as a distorted double cube with two long
from
and
and characterized by
distances,
for the MO
for the W dicubane. In both
et al.
and
compounds the interatomic distances and angles
are quite similar, consistent with the similar ionic
radii of
material’.
and
See also ‘Supplementary
A solution of 0.079 g of
5 ml of acetonitrile was added to a solution of 0.059
(0.25 mmol) in
g of (0.05 mmol) in 60 ml
of acetonitrile. After 24 h at room temperature a
red precipitate was obtained. It was filtered off and
washed with ether. The solid was identified as
by electronic and IR
and electronic spectra
(M = MO, W) approxi-
symmetry so four IR-active vibrations
are expected for the stretching mode.
Only two bands are observed in the corresponding
mate

223
TABLE 1. Crystal data
Formula
Formula weight
Crystal system
Space group
1086
monoclinic
1365
triclinic
P i
monoclinic
90.0
90.0
90.0
3926
4
90.0
2614
4
2733
2
Z
1.838
2123.5
2.349
1825.6
1.660
1355.8
none
CAD4 Enraf-Nonius
0.71069
(g cm-‘)
Systematic absences
Diffractometer
CAD4 Enraf-Nonius
= 0.71069
CAD4 Enraf-Nonius
0.71069
Radiation
M O
(
(
raphite monochromator)
)
Linear absorption coefficient (cm-‘) 35.49
76.85
34.32
Scan type
Scan range
tg
tg
limits
3-50
3437
3-50
3-50
collected
- k , + k ,
I
No. unique data collected
2328
9579
No. unique data used
2672
169
1510
175
8211
337
No. refined parameters
0.038
0.046
0.038
0.043
ref. 7
0.0404
0.0404
Form factors
Secondary extinction
yes
TABLE 2. Selected bond lengths
and angles
for
Distances (A)
1)
1)
1)
1)
1)
1)
1)
1)
1)
W-S(2)
Angles
S(l)-W-S(2)
S(l)-W-S(l)’
1)

224
TABLE 2 (confirmed)
1)
180.00
Mo-S(
Mo-S(
1)
1)
w-S (l)-Cu (2)
w -S (l )-C u (3 )
w-S(2)-Cu (2)
W-S(2)-Cu(3)
S(l)-W-S(2)’
S(2)-W-S(2)’
1)
1)
1)
are given in parentheses; the prime denotes an atom generated by the binary axis.
TABLE 3. Spectral data for
Compounds
anions
340, 310, 290, 275, (m)
340, 310, 290, 275, (m)
434 (4, 2)
308 (12, 5)
448(m), 425(m)
512 (3,
308 (10, 5)
“Positions in cm-r,
pellets.
in nm with molar absorptivities
cm-‘), dmf solutions.
region for the
W dicubane, see Table 3, whereas
The electronic spectra are dominated by the S-M
charge transfers affected by the symmetry effects.
In both compounds the position of the first band
of absorption is shifted owing to the number of
three bands are present for the MO dicubane, shifted
to higher frequencies as usual for molybdenum. In
the 350-250
region where the
are expected the spectra of the two
copper atoms coordinated to the central
core,
pounds are similar, as shown in Table 3.
4 2 4 n m f o r a n d 4 3 4 n m f o r

225
Fig 2. ORTEP drawing of the
aggregate showing the atom numbering. Atoms W,
S(l),
S(3), Cl(l) lie in the mirror plane.
Fig. 3. View of ‘the bidimensional arrangement along the
direction of the
502 nm for
and
tetrahedral group. The tetrathiometallate acts
512 nm for
as a tetradentate ligand towards four copper atoms
as shown in Fig. 2 with
distances ranging
The Cl(l), W,
S(1) atoms are located in the mirror
from
S(3),
to
Crystal structure of
2
of
The
structure
consists
of
neutral
plane. The
to the Cl(l) and
and
atoms are coordinated
atoms, respectively, and the
molecules containing the distorted

226
the out-plane
(see Table 5). Both values remain comparable with
the bridging distances observed in the
dimer No graphitic inter-
actions exist between two adjacent chains consistent
with C-C interchain distances larger than 3.6
separation of
and
atoms related by the mirror are
bonded each to a bipyridine ligand (angle between
the two bipy cycles = 10.41”). The central core forms
a distorted cube (W S(1) S(2) S’(2)
with a missing comer and an additional face
(S(3)
S(1) W) lying in the mirror. The terminal
atoms serve as interaggregate bridges
units to form infinite chains
The W-S(3) bond is short,
closer to
Cl( 1) and
between the
running along the
3. The and
axis passing through the inversion centre at
are symmetrically disposed with respect to the mirror
plane. Thus the
pendicular to the mirror. The
in the mirror are related by the C2 axis passing
through the inversion centre at
so the corresponding Cl(l),
a terminal W=S bond than to a W-S-Cu bridge.
This observation, together with the evidence in the
axis as represented in Fig.
atoms located on the C2
Fourier-difference map processed at R
of a
from the S(1) atom and the
significantly high value of the isotropic thermal pa-
residual peak at 0.7
rameter of the
and
atoms, led us to
bridge is per-
and lying
postulate a lack of
With this hypothesis the
occupancy factors of the
and
atoms
converged to 0.75 and occupations values of 0.75
and 0.25 were found for the S( 1) and S(l)* disordered
positions, respectively giving a R index of 0.038. In
(see Fig. 3)
bridge is
contained in the mirror. The in-plane
the additional face (W S(3)
S(1)) a
are unsymmetrical
and
distances
molecule is statistically missing every four units
(occupancy 0.75) leading to the formation of the
and
and quite different from
TABLE 4. Fractional atomic coordinates for
Atom
Occu pa n cy
1
0.0332
0.0482
0.0439
0.0501
0.0329
0.0102
0.0380
0.0625
0.0439
0.0544
0.0408
0.0476
0.0516
0.0551
0.0544
0.0445
0.0375
0.0410
0.0498
0.0607
0.0595
0.0528
0.0000
W(1)
1)
1)
1)
1.00
0.75
0.75
0.25
1.00
1.00
1.00
0.75
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
0.0000
0.0000
0.0000
0.0000
S(1)
S(2)
S(3)
0.0000
0.0000
0.0000
0.0000
N(1)
N(2)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
1)
1)
1)
1)
1)
1)
1)
0.0496
0.0070
0.1792
0.3977
0.5868
0.7874
0.7942
0.6091
0.1945
0.3112
0.3865
0.3422
0.2893
0.2278
0.1090
0.0601
0.1697
0.1280
0.0966
0.1026
0.0845
0.0825
0.1295
0.1966
H(1)
H(2)
H(3)
H(4)
H(7)
1)
1)
1)
1)
1)
1)
1)
H(9)
in parentheses refer to last digit. Asterisk indicates a disordered position.

227
TABLE 5. Selected interatomic distances
and angles
for
Distances
W(l)-S(3)
W(l)-S(2)
W(l)-Cu (2)
1)
1)
Angles
1)
1)-W(l)-Cu(3)
S(2)-W(l)-S(1)
S(2)-W(l)-S(2)
1)
1)
N(
1)
1)
1)
1)
1)
1)
1)
1)
“Asterisk indicates a disordered position.
terminal
confirmation of this postulated lack of
obtained from the IR spectra of 2 and 2’: a weak
band is observed at 505 characteristic of the
double bond. A fairly experimental
by Miiller et al.
refinements are given in Table 1. See also ‘Supple-
mentary material’.
Results related to the structure
was
vibration of a W=S double bond
Discussion of the reactions
The distribution of the S(1) atom in two different
sites is probably related with the change of the
coordination of the sulfur atom which decreased
from four (in dicubane structure) to three (in
structure) after the removal of
In the dicubane structure, represented in Fig. 1,
the four copper atoms
are tetrahedrally coordinated so only substitution or
elimination reactions are expected.
The structure can then be viewed as
chains statistically distributed
By reaction with
chlorides
anions the four terminal
Cl’(3) are symmetrically
along the
direction (Fig. 3) generating a lacunary
substituted while the trigonal
the binary axis is removed.
The reaction can be viewed as a nucleophilic
substitution of the terminal chloro ligands compli-
cated by an ‘edge-elimination’ as represented in Fig.
The main consequences of this scheme are
atom lying on
structure.
Atom positional parameters for the structure are
given in Table 4; selected interatomic distances and
angles are presented in Table 5. See also ‘Supple-
mentary material’.
that the faces containing the binary axis and the
two bridging chlorines are removed. The product of
the reaction was identified as the tridimensional
Crystal
Except for the additional
structure of is similar to that previously described
of 3
molecule the

elimination of the two chloro bridges to respect the
tetracoordination of and Then the
elimination scheme is intermediate between a
and an edge-elimination.
Supplementary material
Anisotropic thermal parameters (Table SS),
selected bond distances and angles in the bipy ligand
(Table
complete structure results for 1 (Tables
a set of numeric data (Tables S6 to and
an ORTEP drawing for 3 are available from author
F.S. on request.
References
1
2
3
4
A. Miiller, E. Dicmann, R.
Chem., Ed. 20 (1981) 934.
A. Miiller, E. Krickmeyer and H.
Int. Ed. Engl., 25 (1986) 990.
and H.
Chem.,
Fig. 4. Derivatives of the double cubane-like structure: (a)
edge-elimination scheme in dicubane structure; (b)
elimination in dicubane structure giving a cubane-like
F.
J. M. Manoli, C. Potvin and S. Marzak,
Chem.
Dalton Trans., (1988) 3055.
(c) bipy substitution in
anion.
C. Potvin, J. M. Manoli, F.
and S. Marzak,
Chim.
A. Miiller, H.
134 (1987) 9.
and U. Schimanski,
polymer
by direct addition of
With
(4) previously obtained
to
the substitution of the terminal chlorines
Chim.
69 (1983) 5.
J. M. Manoli, C. Potvin, F. Stcheresse and S. Marzak,
Chem. (1986) 15.57.
International Tables for X-ray Crystallography, Vol. IV,
Kynoch Press, Birmingham, U.K., 1974, pp.
A. C. Larson, Crystallographic Computing, Munksgaard,
Copenhagen, 1970, pp. 291.
6
is accompanied by the ‘face-elimination’ of the two
groups and the bridging
chlorine, see Fig. 4(b). The mean plane (con-
taining the trigonal
ing chlorine are retained to complete the geometry
of the monocubane-like structure of 3.
8
9
atom) and the
bridg-
G. M. Sheldrick, SHELX76, crystal solving package,
University of Cambridge, U.K., 1976.
10
D. J. Watkin, J. K. Carruthers and P. W. Betteridge,
Figure 4(c) illustrates the reaction of 1 with
pyridine. The substitution of the terminal
atoms by two molecules of bipyridine is ac-
companied by the elimination of the two Cl(4) and
An Advanced
Program System, Chemical
and
Crystallography Laboratory, University of Oxford, U.K.,
1986.
W. Clegg, C. D. Scattergood and C. D. Garner,
11
12
bridging.atoms and of the
group.
Sect
43 (1987) 786.
The substitution of the two terminal
dentate ligands by two bipy molecules results in the
A. Miiller, W. Jaegermann and W. Hellmann, Mol.
ZOO (1983) 559.