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Mixed Crystals Containing the Diamagnetic Complex [Mo2(SO2)(S2)(CN)8]4 and the Paramagnetic Complex [Mo2(SO2)(S2)(CN)8]5.

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rection) in a corresponding section of the SeF, structure
are reproduced schematically at the bottom of Figure 1.
The shortening of the c-axis in TeF, is due to the strong
fluorine bridges within the polymeric structural assemblage. The fundamental similarity of the arrangements of
the structural units of SeF, and TeF, in the [OlO] direction
also exists in the three-dimensional crystal arrays. The possibility of a structural transformation in SeF, by a closer
(pressure-induced) proximity of the axial fluorine atoms to
selenium atoms of neighboring molecules cannot be ruled
The chemical similarity of SeF, and SFJ6] seems to be
further confirmed by the-albeit up to - 160°C disordered-crystal structure of SFL7', from which a formation of
fluorine-bridged associates in crystalline SF4 is not to be
Received: August 26, 1983;
supplemented: March 23, 1984 [Z 532 IE]
German version: Angew. Chem. 96 (1984) 351
- Mo2
[l] K. Seppelt, Z. Anorg. Allg. Chem. 416 (1975) 12.
[2] A. J. Edwards, F. I. Hewaidy, J . Chem. SOC.A1968, 2977.
[3] A. L. Oppegard, W. C. Smith, E. L. Muetterties, V. A. Engelhardt, J. Am.
Chem. Soc. 82 (1960) 3853.
[4] D. Lentz, H. Pritzkow, K. Seppelt, Inorg. Chem. 17 (1978) 1926.
[5] Crystallographic data: SeF,: 1220 (1378) reflections: R = 5.9%; P212121:
a=5.169(1), b=5.548(1), c=11.345(2) A; Z = 4 ; pCal,=3.16 g/cm3.TeF,: 1525 (1608) reflections, R=6.0%; P212121;a=5.214(4), b=6.229(5),
c=9.414(7) A; Z = 4 ; p,.,,=4.37 g/cm3. Further details of the crystal
structure investigation are available from the Fachinformationszentrum
Energie Physik Mathematik, D-7514 Eggenstein-Leopoldshafen 2, on
quoting the depository number CSD 50827, the names of the authors,
and the journal citation.
[6] K. Seppelt, Angew. Chem. 91 (1979) 199; Angew. Chem. Int. Ed. Engl. 18
(1979) 186.
[7] L. Korte, Dissertation, Universitat Dusseldorf 1983.
M03 - M o l 2681111
Fig. 1. ORTEP plot of the complex anions at the positions A and B in the
asymmetric unit of crystals of 1 [4] (distances in pm). Further details of the
crystal structure determination are available on request from the FachinforMixed Crystals Containing
mationszentrum Energie Physik Mathematik, D-7514 Eggenstein-Leopoldsthe Diamagnetic Complex [ M O ~ ( S O ~ ) ( S ~ ) ( Cand
N ) ~ ~ ~ "hafen 2, on quoting the depository number CSD 50676, the names of the authe Paramagnetic Complex I M O ~ ( S O ~ ) ( S ~ ) ( C N ) , ~ ~thors,
~ and the journal citation.
By Achim Muller*, Werner Eltzner, Rainer Jostes,
Hartmut Bogge, Ekkehard Diemann, Jurgen Schirnanski,
and Heiko Lueken
In the crystal, the complexes l a and l b are located at
Paramagnetic multinuclear and, particularly, binuclear
crystallographically independent positions A and B
complexes of the heavy transition metals (4d and 3d ele(Fig. 1). The structures of l a and l b differ only slightly; in
ments) are rare. We have now been able to isolate a
both complexes each molybdenum atom is surrounded by
compound which contains the isostructural anions
an approximately pentagonal-bipyramidal array of four
[ ( M O " ' ~ ' ~ ) ~ ( S O ~ ) ( S ~ ) ( Cl aN ) ~(paramagnetic)
CNe and three sulfur atoms of the bridging ligands
l b) ~
together in a
and S:Q[51. However, markedly different Mo-Mo
mixed crystal compound.
are observed for the positions A and B (279.0
Passage of oxygen into an aqueous solution of
and 268.4 pm, respectively). Since the greater Mo-Mo dis[ ( M O " ' ) ~ ( S ) ~ ( C N 2["leads
) ~ ] ~ ~ to the formation of a blackish
tance is to be expected for l a (see below), this complex obviolet mixed-crystal compound of the composition & + x viously preferably occupies the position A ; but since the
[ ( M ~ ' " ~ ' ~ ) z ( ~ ~ ~ ) ( ~ z ~ ~ ~ ~ ~--x.
s 4l H~z 0~ ~ ~ ~ ' ~ ~ z ~ ~ ~ z ) ( ~ z ) ( ~ ~ ) ~ l ~
crystal contains only ca. 30% of la, the geometric parame1 (x = 0.3) l l 3 ] . 1 was characterized magnetochemically
ters cannot exclusively arise from l a , at least in the case of
and spectroscopically (ESCA, ESR, IR, UV/VIS/NIR),
and by an X-ray structure analysis (Fig. l)',].
By ESCA measurementsL6]it was possible to demonstrate that mixed valence Mo species are present in 1.
Moreover, from the hyperfine structure of the ESR spec[*] Prof. Dr. A. Miiller, Dr. W. Eltzner, Dr. R. Jostes, Dr. H. Biigge,
Dr. E. Diemann, J. Schimanski
trum (solution of 1 in water, addition of Na2S03[71,room
Fakultat fur Chemie der Universitat
temperature) it unequivocally follows that an unpaired
Postfach 8640, D-4800 Bielefeld 1 (FRG)
electron in l a interacts with the nuclear spin of two chemiProf. Dr. H. Lueken
cally equivalent Mo atoms (95Moand 97Mo with I = 5/2).
Institut fur Anorganische Chemie der Technischen Universitat
The measured parameters ij= 2.012 and x(95Mo)= 19.2 G
Paul-Ernst-Str. 4, D-3392 Clausthal-Zellerfeld (FRG)
Angew. Chem. Int. Ed. Engl. 23 (1984) No. 5
0 Verlag Chemie GmhH, 0-6940 Weinheirn, 1984
0570-0833/84/0.505-0389 $02.50/0
point to a strong delocalization of the unpaired electron
(e.g. in comparison to that in [ M O ~ ( S O ~ ) ~ ] ~ ~ [ ~ ~ ) .
The electronic absorption spectrum of 1 in aqueous solution (addition of Na2S03171)
reveals the presence of both
l a (980, 340 (sh), 305 nm) and l b (900, 550, 410 (sh), 340,
280 (sh), 230 nm)191.The time-dependent measurement of
the IR spectra of an aqueous solution of 1, through which
O2 is passed, permits monitoring of the conversion of l a
(v(CN): 2103 cm-') into l b (v(CN): 2134 cm-I); the ESR
signal of l a correspondingly disappears.
The proportion of the binuclear unit l a in the mixed
crystal was estimated from susceptibility measurements
(Faraday method) to be 31%1101.
An SCCC-EH-MO calculation on l b showed that the
species can be best described as a ( M O ' ~ ) ~ / S O ~ ~com/S:~
plex with a metal-metal double bond (two occupied MOs
with pronounced Mo-4d character, configuration approximately 0%'); formally, the 18-electron rule is fulfilled. The
additional electron in l a occupies a weakly Mo-Mo antibonding MO (-&*), from which the greater atomic distance is feasible.
Also remarkable is the reaction path leading to 1. Passage of O2 into a solution of 2 leads to successive formation of [ ( M O ' ~ ) ~ ( S ) , ( C N 311'],
) ~ ] ~ l~a , and l b :
Under the given conditionsr3],l a and l b crystallize out together in the mixed-crystal compound 1. In the case of
reactions (a) and (c) the conversion of isostructural species
with different electron populations takes place via twoand one-electron oxidation processes, respectively (detecand l b : El,z
tion by CV measurements on 2 and 3r111
= 0.06 V relative to the potential of the normal hydrogen
electrode), whereas reaction (b) involving formation of the
S 0 z Q and S:" bridging-ligands is more complicated and
not understood.
the salt 1 can be classiAccording to Robin and
fied as a mixed-valence compound of type I, while the anion l a can be assigned to the type I11 (complete delocalization).
Received: December 5, 1983;
revised: March 20, 1984 [Z 646 IE]
German version: Angew. Chem. 96 (1984) 355
CAS Registry number:
2'6K, 71788-85-7.
[I] The oxidation states of the molybdenum atoms are based on the assumption of SO:e and s:" ligands. Supporting evidence for the presence of a SO:e ligand [cf. also D. M. Hoffman, R. Hoffmann, Inorg.
Chem. 20 (1981) 35431 is provided by ESCA data (very low value for
E ~ S Z P ~ , and
~ ) ) IR data (low *SO) value, especially in the case of l a ,
corresponding to large S - 0 distances; solid-state spectrum (CsI pellet)
of 1 : 960, 1055 ( l a ) ; 1016, 1131 cm-' ( l b ) [cf. R. R. Ryan, G. J. Kubas,
D. C. Moody, P. G. Eller, Sfruct. Bonding (Berlin) 46 (1981) 471; the intensity of the v(CN) band of l b in aqueous solution is almost as large as
that of [MoL"(S)~(CN),]'~,cf. [ll]).
[2] E. Crepaz, Gazz. Chim. Ital. 58 (1928) 391; P. Christophliemk, Diplomarbeit, Universitat Gottingen 1969; M. G. B. Drew, P. C. H. Mitchell,
C. F. Pygall, Angew. Chem. 88 (1976) 855; Angew. Chem. Int. Ed. Engl.
15 (1976) 784.
[3] Oxygen is bubbled into a solution of & [MOZ (S )~ (CN)~ ]. ~[2]
H~2O(2 g)
in H 2 0 (20 mL) and glacial acetic acid (0.5 mL) for 3 h. The reddish
brown precipitate is filtered off and further oxygen passed into the filtrate until a violet solution is obtained (ca. 2 h). After renewed filtration
the solution is transferred to a crystallizing dish and allowed to evaporate down to ca. 5 mL in a desiccator over P4010.After about a week the
colorless byproducts are filtered off and the filtrate (covered with a
watch glass) is allowed to stand for 1-2 weeks at room temperature in
presence of air. The large, blackish violet crystals of 1 which separate
out (ca. 0.2 g), are dried between filter papers.
0 Verlag Chemie GmbH, 0-6940 Weinheim. 1984
141 Space group Pi, a=1051.9(2), b=1581.6(4), c=1616.6(4) pm,
a=106.68(2),8=95.10(2), y = 101.61(2)", Z = 2 ; R=0.061 for 6990 independent reflections (Fo> 3.92u(Fo)), MoKn radiation, Syntex P2,. The
binuclear anions are grouped in pairs that are located almost parallel to
each other in the crystal lattice (Mo positions ofA and B : Mol -0,1491,
0.2770, 0.2934; Mo2 0.1209, 0.3352, 0.2983 and Mo3 0.0344, 0.2888,
0.7166; Mo4 -0.2251, 0.2227, 0.7029). The K' cations are distributed
over nine lattice sites of the asymmetric unit, of which three are not fully
151 The molecular structure of diamagnetic l b in the PPhf' salt [C. Potvin, J.
M. Brbgeault, J. M. Manoli, J . Chem. SOC.
Chem. Commun. 1980, 6641
corresponds to that found here.
161 Hewlett-Packard 5950A spectrometer, monochromatic AIK, radiation,
standard: K2p3,,=292.2 eV; Mo3dSI2 228.0 and 229.2, S2p3,, 163.4
(S:") and 165.1 eV
[71 The addition of Na2S03provides an easy way of preventing the oxidation l a - l b by traces of oxygen, without any reduction l b - l a taking
place (checked by measurements on carefully degassed solutions).
[8] F. A. Cotton, B. A. Frenz, E. Pedersen, T. R. Webb, Inorg. Chem. 14
(1975) 391.
[9] The two complex anions could be identified on the basis of the pure diamagnetic CQmpound (PPh&Mo2(SOz)(Sz)(CN)n].6 H 2 0 and the Km
salts of l a (contaminated with K2S04) and l b , now prepared by us,
[lo] The magnetic behavior between 10 and 300 K can be described by the
relationship x = C / T + x o (with C=0.2939x lo-' m3 K mol-' and
xo= 191 x lo-'' m3 mol-'; SI units). The Curie term of l a (s= 1/2) is
determined under the formal assumption of strong antiferromagnetic interactions between the Mo atoms in the binuclear units. From its magnitude (and using g=2.012 obtained from the ESR experiment) the given
composition can therefore be determined. The positive ,yo value indicates contributions from temperature-independent paramagnetism
(measurements at the Technische Hochschule Aachen).
[ l l ] A. Muller et al., unpublished results.
[I21 M. B. Robin, P. Day, Adv. Inorg. Chem. Radiochem. 10 (1967) 247.
All-cis-[]fenestrane* *
By Marcel Luyten and Reinhart Keese*
Dedicated to Dr. Ulrich Weiss on the occasion of his 75th
Fenestranes are of particular interest because they belong to the class of compounds which contain tetracoordinate carbon with planoid configuration"]. We now wish to
report that reductive decarboxylation of 1Iz1gave the saturated hydrocarbon 2, the all-~is-[]fenestrane~~-~~.
Because of the specific structural properties and the
steric hindrance it seemed unlikely that 1 could be transformed into 2 by typical multistep methods used for decarboxylation of lactones. In particular, ring-opening reactions, potentially leading from 1 to a y-hydrocarboxylate
or a corresponding derivative, could be excluded, because
of the high tendency of lactone formation in similar
We have now found that 1 can be reductively decarboxylated to 2 in presence of hydrogen and Pd as a catalystI61.
Pd-C / H p
[*I Prof. Dr. R. Keese, M. Luyten
Institut fur organische Chemie der Universitat
Freiestrasse 3, CH-3012 Bern (Switzerland)
[**I This work was supported by the Swiss National Science Foundation
(project No. 2.421-0.82).
0570-0833/84/0505-0390 $ 02.50/0
Angew. Chem. Int. Ed. Engl. 23 (1984) No. 5
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