As a source of semi-interstitial phosphorus ligands in cobalt carbonyl clusters

Article abstract of DOI:10.1021/om100428p

The PH₃-containing complex [(CO)₄W(PH ₃)₂] (1) is synthesized in good yields by the one-pot reaction of [(CO)₄W(nbd)] (nbd = norbonadiene) with P(SiMe₃)₃ and subsequent methanolysis of the reaction mixture. The further reaction of [(CO)₄W(PH₃) ₂] with [Co₂(CO)₈] results in three novel cobalt clusters, [Co₈(CO)₁₈(μ₆-P) ₂(μ-CO)] (2), [Co₁₀(CO)₁₈(μ₇- P)₂(μ-CO)₆] (3), and [[Co₃(CO) ₈{μ₄-PW(CO)₅}][(μ₄-P)Co ₃(CO)₉]] (4). All products have been comprehensively characterized including X-ray diffraction.

Full text of DOI:10.1021/om100428p

Organometallics 2010, 29, 5187–5191 5187
DOI: 10.1021/om100428p
[(CO)4W(PH3)2] as a Source of Semi-interstitial Phosphorus Ligands
in Cobalt Carbonyl Clusters†
Cornelia Dreher, Manfred Zabel, Michael Bodensteiner, and Manfred Scheer*
€
Institut fu€r Anorganische Chemie, Universitat Regensburg, Regensburg D-93053, Germany
Received May 5, 2010
The PH3-containing complex [(CO)4W(PH3)2] (1) is synthesized in good yields by the “one-pot”
reaction of [(CO)4W(nbd)] (nbd = norbonadiene) with P(SiMe3)3 and subsequent methanolysis
of the reaction mixture. The further reaction of [(CO)4W(PH3)2] with [Co2(CO)8] results in three
novel cobalt clusters, [Co8(CO)18( μ6-P)2( μ-CO)] (2), [Co10(CO)18( μ7-P)2( μ-CO)6] (3), and [[Co3(CO)8-
{μ4-PW(CO)5}][( μ4-P)Co3(CO)9]] (4). All products have been comprehensively characterized including
X-ray diffraction.
Introduction
reported the synthesis of several phosphido ligand complexes
using [Co2(CO)8] as starting material (eq 2).10
PH3-functionalized complexes have been known since
1986,1 when Fischer synthesized the first PH3 complex,
[(CO)4M(PH3)2] (M = Cr, Mo, W), accidentally, by the
reaction of [(CO)5M(C(OCH3)CH3)] with PH3, in order to
obtain the P analogue complex of [(CO)5M(C(NH2)CH3)].2
Afterwards, many attempts have been made to synthesize
transition metal complexes of the general formulas
[(CO)xM(PH3)6-x] (x = 3, 4, 5).3-5
The starting material PH3 possesses some disadvantages
such as its toxicity and flammability as well as its low dona-
tion ability towards transition metal compounds. To avoid
PH3 as starting material, Mathey et al. allowed PH4I to react
with [W(CO)5L] (L = THF, CH3CN) to yield [(CO)5W-
(PH3)].6 Schafer et al. introduced the methanolysis of
€
the Me3Si-substituted complexes [LnMP(SiMe3)3] (LnM =
Cr(CO)5, CpMn(CO)2, Fe(CO)4) to obtain the correspond-
ing PH3-containing complexes.7 Alternatively, we developed
a “one-pot” synthesis of [(CO)5W(EH3)] (E = P, As) in good
yields, using E(SiMe3)3 as EH3 source.8 In this way, the first
AsH3 ligand complex could be synthesized.
Due to the experimental difficulties, only a limited number
of reactivity studies of PH3-functionalized transition metal
carbonyl complexes have been published. The first was given
by Urry et al. (eq 1).9 Furthermore, Vahrenkamp et al. have
Large anionic phosphorus-containing cobalt clusters such
as [PPh4][Co6(CO14)( μ-CO)2P)] and [Co10P2(CO)23H]2- (5)
have been synthesized by Chini et al.11,12 and by Long et al.,13
using salt elimination reactions, for example with PBr3 as a
source of phosphorus.13
Herein we report
a novel “one-pot” synthesis of
[(CO)4W(PH3)2] and its use as a source for the formation
of novel Co clusters with semi-interstitial phosphorus atoms.
† Part of the Dietmar Seyferth Festschrift. Dedicated to Dietmar Seyferth.
*To whom correspondence should be addressed. E-mail: manfred.
scheer@chemie.uni-regensburg.de.
(1) Fischer, E. O.; Louis, E.; Bathelt, W.; Moser, E.; Mueller, J.
J. Organomet. Chem. 1968, 14, P9–P12.
(2) Klabunde, U.; Fischer, E. O. J. Am. Chem. Soc. 1967, 89, 7141–
7142.
(3) Guggenberger, L. J.; Klabunde, U.; Schunn, R. A. Inorg. Chem.
Results and Discussion
[(CO)4W(PH3)2] (1) is synthesized in good yields by
the reaction of [(CO)4W(nbd)] (nbd =norbonadiene) with
P(SiMe3)3 and subsequent methanolysis of the reaction
mixture. The yellow compound 1 is purified by sublimation.
The reaction of 1 with Co2(CO)8 at room temperature in a
1:1 stoichiometry results in the formation of W(CO)6 and the
1973, 12, 1143–1148.
(4) Fischer, E. O.; Louis, E.; Bathelt, W.; Mueller, J. Chem. Ber. 1969,
102, 2547–2556.
(5) Fischer, E. O.; Louis, E.; Schneider, R. J. J. Angew. Chem. 1968,
80, 122–123.
(6) Nief, F.; Mercier, F.; Mathey, F. J. Organomet. Chem. 1987, 328,
349–355.
(7) Schaefer, H.; Leske, W. Z. Anorg. Allg. Chem. 1987, 552, 50–68.
(8) Vogel, U.; Scheer, M. Z. Anorg. Allg. Chem. 2001, 627, 1593–1598.
(9) Austin, R. G.; Urry, G. Inorg. Chem. 1977, 16, 3359–3360.
(10) De, R. L.; Vahrenkamp, H. Z. Naturforsch., B: Anorg. Chem.,
Org. Chem. 1985, 40B, 1250–1257.
(11) Chini, P.; Ciani, G.; Martinengo, S.; Sironi, A.; Longhetti, L.;
Heaton, B. T. J. Chem. Soc., Chem. Commun. 1979, 188–189.
(12) Ciani, G.; Sironi, A. J. Organomet. Chem. 1983, 241, 385–393.
(13) Hong, C. S.; Berben, L. A.; Long, J. R. Dalton Trans. 2003, 2119–
2120.
r
2010 American Chemical Society
Published on Web 07/27/2010
pubs.acs.org/Organometallics

5188 Organometallics, Vol. 29, No. 21, 2010
Dreher et al.
cobalt cluster [Co8(CO)18( μ6-P)2( μ-CO)] (2) (eq 3) as a
brown crystalline compound in moderate yields.
- 11CO
½ðCOÞ4WðPH3Þ2ꢀ þ 4½Co2ðCOÞ8ꢀ
f
- 3H2
1
½WðCOÞ6ꢀ þ ½Co8ðCOÞ18ðμ6-PÞ2ðμ-COÞꢀ
2
ð3Þ
In order to increase the yield of 2, the stoichiometry was
adapted to the composition of 2 (1:4 stoichiometry). How-
ever, this reaction results in two novel brown crystalline
cobalt clusters, [Co10(CO)18( μ7-P)2( μ-CO)6] (3) as the minor
and [[Co3(CO)8{μ4-PW(CO)5}][( μ4-P)Co3(CO)9]] (4) as the
major product (eq 4).
2½ðCOÞ WðPH3Þ þ 8½Co2ðCOÞ ꢀ- 12H = - 20CO
2
f
4
2
8
- ½WðCOÞ6ꢀ
1
½Co10ðCOÞ18ðμ7-PÞ2ðμ-COÞ6ꢀ 3 þ
½fCo3ðCOÞ8fμ4-PWðCOÞ5ggfðμ4-PÞCo3ðCOÞ9gꢀ 4
ð4Þ
Characterization and Spectroscopic Properties. Compounds
1 and 3 are soluble in nonpolar solvents, such as n-hexane or
toluene, whereas 2 and 4 are only soluble in more polar
solvents such as CH2Cl2. In the FD mass spectra of 1, 2, and
4 the appropriate molecular ion peaks are found. It is not
observed for 3 due to decomposition. Additionally, in the EI
mass spectrum of 1 a characteristic fragmentation pattern
of successive CO elimination is observed. The IR spectrum
of 1 shows four absorptions for the CO stretching frequencies
at 2034(s), 1941(s), 1923(s), and 1893(w) cm-1 as a result of its
local C2v symmetry. Furthermore, a typical absorption at
2325(m) cm-1 for the P-H valence stretching frequency is ob-
served. These results are in accordance with the data found
for [cis-(CO)4W(PH3)2].1 The IR spectra of the compounds
2-4 show typical absorptions for the CO valence frequencies
between 2120 and 1880 cm-1 for terminal CO ligands. Addi-
tionally 2 shows an absorption at 1852 cm-1 for the bridging
CO ligand. In contrast no absorptions for bridging CO ligands
are found for 3 in solution. The NMR data of 1 were
previously described in the literature.1,14,15 In addition we
could verify the coupling constants for the multiplets of higher
order in the 31P and 1H NMR spectra by simulation (Figure 1).
For 2 and 3 no peaks can be observed in the 31P{1H} NMR
spectra as a consequence of the large magnetic spin moment
of the 59Co nucleus (I = 7/2). In these clusters, all interstitial
P atoms are surrounded by six or seven Co atoms, leading to
the broadening and subsequent disappearance of the signals.
In 4 only three and four Co atoms, respectively, surround the P
atoms. Therefore, in the 31P{1H} NMR spectrum broad signals
at 650 ppm (ω1/2=163 Hz) and 575 ppm (ω1/2=114 Hz) can be
found.
Figure 1. Experimental (C6D6, 300 K, top) and simulated
(bottom) 1H NMR (a) and 31P NMR (b) spectra of 1. Calculated
2
1
3
coupling constants: JPP =13.0 Hz, JPH =328.6 Hz, JPH
11.2 Hz, 1JPW=207.2 Hz.
=
Figure 2. Molecular structure of 1 in the crystal (50% pro-
bability level). Only one orientation of the disordered atoms P2,
˚
C3, and O3 is represented for clarity. Selected bond lengths (A)
and angles (deg): W1-P1 2.492(1), W1-P2 2.493(5), W1-C1
2.023(6), W1-C2 1.968(8), W1-C3 1.937(7), P1-W1-P2
86.8(6), P1-W1-C1 88.8(6), P1-W1-C2 178.9(3), P1-W1-
C3 89.5(3).
Crystal Structure Analysis. Crystals of 1 suitable for X-ray
crystal structure determination were obtained from a CH2Cl2
solution of 1 at -25 °C. Compound 1 crystallizes in the ortho-
rhombic space group Pnma. Due to a mirror plane, which
contains P1, W1, C2, and O2, the atoms C3 and O3 as well
as P2 are disordered over two positions with an occupancy
of 50% (Figure 2). The positions of the hydrogen atoms of the
(14) Moser, E.; Fischer, E. O.; Bathelt, W.; Gretner, W.; Knauss, L.;
Louis, E. J. Organomet. Chem. 1969, 19, 377–385.
(15) Moser, E.; Fischer, E. O. J. Organomet. Chem. 1968, 15, 157–163.

Article
Organometallics, Vol. 29, No. 21, 2010 5189
˚
Figure 3. Cluster core (a) and molecular structure (b) of 2 in the crystal (50% probability level). Selected bond lengths (A): Co1-Co2
2.659(3), Co2-Co3 2.401(4), Co3-Co4 2.689(9), Co1-Co4 2.604(3), Co-C4(av) 1.908(3), Co-Cterminal(av) 1.817(4).
˚
Figure 4. Cluster core (a) and molecular structure (b) of 3 in the crystal (50% probability level). Selected bond lengths (A): Co2-Co6
2.616(4), Co3-Co5 2.575(6), Co4-Co9 2.566(5), Co7-Co8 2.623(4), Co1-Co2 2.660(9), Co3-Co4 2.640(1), Co8-Co10 2.637(6),
Co5-Co9 2.655(2).
˚
latter bond is noticeably shortened (2.401(3) A) compared to
PH3 groups could not be located in the difference Fourier
map, and their positions are calculated. The structure of 1
reveals four carbonyl and two phosphane ligands, forming a
distorted octahedron around the central W atom with bond
angles between 94.1° and 85.8° and 172.7° and 178.9°, res-
˚
the remaining nonbridged bonds (Co1-Co2 = 2.659(3) A,
˚
˚
Co3-Co4 = 2.689(9) A, Co1-Co4 = 2.604(3) A). The
bridging coordination mode is also reflected in a slightly
˚
elongated Co-C bond length of 1.908(3) A (av) compared to
those of the terminal CO ligands (1.817(4) A (av)).
˚
˚
pectively. The P-W bond lengths of 2.492(1) and 2.493(5) A
are comparable to that in the monophosphane complex
8
[(CO)5W(PH3)] (2.491(2) A) and are slightly shortened in
Compound 3 crystallizes in the monoclinic space group
P21/c. The molecular structure and the view of the cluster core
are depicted in Figure 4. The cluster core of 3 is comparable to
that of 2. It also consists of a distorted octahedron containing
four Co and two P atoms, and three equatorial Co-P edges
are bridged by a Co3 unit, leading to an unusual linkage to the
Co2P faces. This results in an unusual coordination number of
seven for the phosphorus atoms.
˚
comparison to the triphenylphosphane complex [(CO)5W-
16
(PPh3)] (2.545(1) A), which is a consequence of the better
˚
π-acceptor ability of PH3 compared to PPh3.
Compound 2 crystallizes in the monoclinic space group
P21/c. The molecular structure and the view of the cluster
core of 2 are depicted in Figure 3. The cluster core of 2
consists of a distorted octahedron containing four Co and
two P atoms, in which four of the faces are capped by one Co
atom. This results in the unusual coordination number six
for the phosphorus atoms. The distortion of the octahedron
originates in the difference between the Co-Co and the
Co-P bond length. As depicted in Figure 3b an additional
asymmetric distortion of the octahedral core of 2 is a
consequence of two different types of CO ligands. Whereas
most of the CO groups are terminal ligands, the Co2-Co3
bond is symmetrically bridged by a CO ligand. Hence, the
The cluster core of 3 is comparable to that of the charged
compound [Co10P2(CO)23H]2- (5),13 with similar bond lengths.
All Co-Co distances are in the range between 2.566(5) and
˚
2.696(6) A. However, the main difference from 5 is found in the
different connectivity of the μ3-bridging Co atoms. In 5 two Co3
units are symmetrically capping a central P2Co4 octahedron.
The central P2Co4 octahedron in 3 is asymmetrically capped by
two Co3 units. One Co3 unit is capping the two faces defined by
the atoms Co5, P2, Co4 and P2, Co4, Co7 (comparable to 5),
whereas the second Co3 unit is capping the faces defined by
the atoms Co4, P1, Co5 and P1, Co5, Co6, which differs
from the arrangement in 5 (Figure 4a). Together with 5 and
[Co6P(CO)16]-11,12 the novel clusters 2 and 3 are, to our
(16) Aroney, M. J.; Buys, I. E.; Davies, M. S.; Hambley, T. W.
J. Chem. Soc., Dalton Trans.: Inorg. Chem. 1994, 2827–2834.

5190 Organometallics, Vol. 29, No. 21, 2010
Dreher et al.
˚
The Co-Co distances in 4 (2.5389(4) to 2.543(2) A) show
no remarkable difference from those in 6 (2.537(4) to
10
˚
2.548(4) A). Only the bond lengths Co1-Co3 and Co2-
Co3 are elongated (2.575(2) and 2.557(9) A) as a result of
˚
the sterical influence of the PCo3 tetrahedron, which is
connected to the Co3 atom.
Conclusions
The novel “one-pot” synthesis of [(CO)4W(PH3)2] is based
on the methanolysis of [(CO)4W{P(SiMe3)3}] synthesized by
the reaction of [(CO)4W(nbd)] with P(SiMe3)3. This versatile
compound is a suitable starting material for the synthesis of
novel cobalt carbonyl clusters with unprecedented semi-
interstitial phosphorus ligands. This general method opens
broad perspectives for the synthesis of new clusters contain-
ing interstitial group 15 element ligands.
Experimental Section
Figure 5. Molecular structure of 4 in the crystal (50% prob-
˚
ability level). Selected bond lengths (A): W1-P1 2.458(4),
General Remarks. All manipulations were carried out under a
nitrogen atmosphere using standard Schlenk techniques. All
solvents were dried using standard procedures and freshly
distilled prior to use. All NMR spectra were recorded on a
Bruker Avance 400 (1H, 400.132 MHz; 31P, 161.975 MHz) with
δ referenced to external SiMe4 (1H) or H3PO4 (31P), respectively.
TheNMRspectraweresimulatedwiththeprogramWINDAISY.17
IR spectra were recorded on a Varian FTS-800 spectrometer. Mass
spectra were determined on a Finnigan MAT 95 (FD) or a Finnigan
MAT SSQ 710 A (EI).
P1-Co1 2.178(7), P1-Co2 2.213(8), P1-Co3 2.176(3),
Co1-Co2 2.538(9), Co1-Co3 2.575(2), Co2-Co3 2.557(9),
Co3-P2 2.181(8), P2-Co4 2.180(1), P2-Co5 2.194(3),
P2-Co6 2.185(8), Co4-Co5 2.540(3), Co4-Co6 2.543(2),
Co5-Co6 2.539(6).
[(CO)4W(PH3)2] (1). A mixture of [(CO)4W(nbd)]18 (2.825 g,
7.28 mmol) and P(SiMe3)319 (4.013 g, 16.02 mmol) was stirred in
THF (150 mL) at room temperature for 30 min. MeOH (1.848 g,
57.67 mmol) was added, and the mixture was stirred for further
14 h. Removing the solvent under reduced pressure yielded a
yellow crude product of 1, which was purified by sublimation at
60 °C and 10-3 mbar. Single crystals were obtained by dissolving
1 in 20 mL of CH2Cl2 and storage at -25 °C. Yield: 1.685 g
(64%). IR (toluene solution): ν~CO 2034(s), 1941(s), 1923(s),
1893(w) cm-1; ν~PH 2325(w) cm-1 1H NMR (400.132 MHz,
.
C6D6): δ 2.78 (m,1JPH = 328.6 Hz, 3JPH = 11.2 Hz, 6 H, PH3)
(coupling constants have been determined by simulation of the
NMR spectra). 31P{1H} NMR (161.975 MHz, C6D6): δ -177 (s,
1JPW = 207.2 Hz, PH3). 31P NMR (161.975MHz, C6D6): δ -177
Figure 6. Comparison of the structures of 4 and 6.
knowledge, the only examples containing semi-interstitial P
atoms.
(m, 2JPP = 13.0 Hz, 1JPH = 328.6 Hz, 3JPH = 11.2 Hz, 1JPW
=
207.2 Hz, PH3). EI-MS: m/z (%) 364 (58) [(CO)4W(PH3)2]þ, 336
(18) [(CO)3W(PH3)2]þ, 308 (84) [(CO)2W(PH3)2]þ, 280 (86)
[(CO)W(PH3)2]þ, 252 (39) [W(PH3)2]þ. Anal. Calcd for WP2C4-
O4H6: C, 13.20; H, 1.66. Found: C, 13.56; H, 1.82.
Similar to 2, an asymmetrical distortion, based on the
different types of CO ligands, is found in 3, which is not as
pronounced as in 2. Whereas each of the atoms Co2 and Co6,
Co3 and Co5, Co4 and Co9, and Co8 and Co7 are symme-
trically bridged by CO ligands, the Co1-Co2, Co3-Co4,
Co8-Co10, and Co5-Co9 bonds are semibridged by a
carbonyl ligand (Figure 4b). Interestingly, the Co-Co dis-
tances bearing a bridging CO unit (e.g., d(Co4-Co9) =
[Co8(CO)18( μ6-P)2( μ-CO)] (2). A mixture of [(CO)4W(PH3)2]
(1) (364 mg, 1 mmol) and [Co2(CO)8] (342 mg, 1 mmol) was
stirred in toluene (50 mL) at room temperature for three days.
Removing the solvent under reduced pressure yields a brown
crude product, which was initially extracted three times with
10 mL of hexane to remove the formed [W(CO)6], followed
by an extraction with 20 mL of CH2Cl2 and filtration of the
resulting solution. Reducing the solvent to 10 mL and storage
at -25 °C yielded brown-black crystals of 2. Yield (based on Co):
116 mg (44%). IR (KBr): ν~CO 2103(w), 2055(s), 2022(s), 1934(s),
1917(s), 1886(s), 1852(s) cm-1. FD-MS: m/z (%) 1065 (100) Mþ.
Anal. Calcd for CoP2C19O19: C, 21.42. Found: C, 20.98.
˚
˚
2.566(5) A and d(Co7-Co8) = 2.623(4) A) are longer
˚
compared to those in 2 (2.401(4) A).
Compound 4 crystallizes in the monoclinic space group
C2/c; the molecular structure is depicted in Figure 5. Com-
pound 4 exhibits two PCo3 tetrahedrons, which are con-
nected by the coordination of one PCo3 moiety to the other
WPCo3 unit. The formation of a polymer is hindered by
the coordination of the P1 atom to a W(CO)5 fragment,
and thus the dimer is formed. Interestingly, the reaction of
[(CO)5W(PH3)] with [Co2(CO)8] yielded the monomeric
compound [WCo3P(CO)14] (6).10 The comparison of both
products is depicted in Figure 6.
(17) WINDAISY, Version 4.05; Bruker-Franzen Analytik GmbH.
(18) King, R. B.; Fronzaglia, A. Chem. Commun. (London) 1965, 547–
549.
(19) Uhlig, F.; Gremler, S.; Dargatz, M.; Scheer, M.; Herrmann, E.
Z. Anorg. Allg. Chem. 1991, 606, 105–108.

Article
Organometallics, Vol. 29, No. 21, 2010 5191
Table 1. Crystallographic Data for 1, 2, 3, and 4
1
2
3 0.5C6H14
3
4 0.5CH2Cl2
3
empirical formula
Mr
C4H6O4P2W
363.87
123(2)
C19Co8O19P2
1065.57
123(1)
C27H7Co10O24P2
1366.57
123(1)
C22,5Co6O22P2WHCl
1258.09
173(1)
T [K]
˚
λ [A]
cryst size
1.54178
0.08 ꢁ 0.06 ꢁ 0.04
0.71073
0.38 ꢁ 0.10 ꢁ 0.04
0.71073
0.30 ꢁ 0.17 ꢁ 0.14
0.33 ꢁ 0.15 ꢁ 0.09
C2/c
space group
cryst syst
Pnma
P21/c
P21/c
orthorhombic
12.3310(6)
11.4201(7)
6.7564(3)
90
90
90
951.45(9)
4
2.540
monoclinic
12.3935(13)
15.3098(16)
20.260(2)
90
127.019(9)
90
3069.3(7)
4
2.306
monoclinic
12.4421(8)
11.5336(7)
30.944(2)
90
109.062(7)
90
4197.0(5)
4
2.163
monoclinic
36.524(3)
9.0205(5)
22.6939(18)
90
104.390(9)
90
7242.3(10)
8
2.230
˚
a [A]
˚
b [A]
˚
c [A]
R [deg]
β [deg]
γ [deg]
3
˚
V [A ]
Z
dc [g cm-3
]
μc [mm-1
]
25.494
4.397
4.004
6.014
θ range [deg]
hkl range
3.58-61.88
-13 e h e 11
-12 e k e 12
-7 e l e 7
775/8/71
775 (Rint = 0.0546)
630
2.06-25.85
-15 e h e 15
-18 e k e 18
-24 e l e 24
5902/0/433
5902 (Rint = 0.0429)
5048
2.41-26.91
-15 e h e 15
-14 e k e 14
-39 e l e 39
9030/0/541
9030 (Rint = 0.0862)
4777
1.85-25.91
-44 e h e 44
-11 e k e 11
-27 e l e 27
6979/0/479
6979 (Rint = 0.0569)
5385
data/restraints/params
no. of unique data
indep reflns [I > 2σ(I )]
goodness-of fit on F2
R1, wR2 [I > 2σ(I )]
R1, wR2 [all data]
1.041
1.023
0.701
0.929
0.0380, 0.0924
0.0465, 0.0945
1.185, -1.540
0.0224, 0.0567
0.0279, 0.0578
0.606, -0.429
0.0365, 0.0702
0.0840, 0.0765
0.736, -0.553
0.0323, 0.0731
0.0439, 0.0755
2.369, -1.542
largest diff peak/
]
-3
˚
hole [e A
[Co10(CO)18( μ7-P)2( μ-CO)6] (3) and [[Co3(CO)8{μ4-PW(CO)5}]-
[( μ4-P)Co3(CO)9]] (4).A mixture of [(CO)4W(PH3)2] (1) (364 mg,
1 mmol) and [Co2(CO)8] (1.368 g, 4 mmol) was stirred in toluene
(50 mL) at room temperature for three days. Removing the
solvent under reduced pressure yielded a brown residue, which
was initially extracted three times with 10 mL of n-hexane and
filtered. Reduction of the n-hexane solution to a volume of ca.
15 mL and storage at -25 °C yielded 3 as brown-black crystals
and [Co2(CO)8] as orange crystals. The mixture of crystals was
dried under vacuum. [Co2(CO)8] was removed by sublimation
and after recrystallization of the residue in 10 mL of n-hexane at
-25 °C 3 was obtained as brown-black crystals. Yield (based on
1): 15 mg (2%).
The initial residue of the reaction mixture was further
extracted two times with 10 mL of CH2Cl2 and filtered. Reduc-
tion of the solvent to a volume of ca. 10 mL and storage at
-25 °C yielded brown-black crystals of 4 as a CH2Cl2 solvate.
Yield (based on 1): 300 mg (49%).
Analytical data of 3: IR (CH2Cl2): ν~CO 2119(w), 2085(sh),
2079(s), 2053(br), 2023(m), 1989(w), 1937(br) cm-1. Anal.
Calcd for Co10P2C24O24: C, 21.78. Found: C, 21.31.
Absorption corrections were applied using the semiempirical
method from equivalents for 120 and analytically or numeri-
cally from crystal faces for 2, 3, and 4.21 The structures were
solved by direct methods using SHELXS-9722a or SIR-97,22b
and full matrix least-squares refinements on F2 in SHELXL-
9722c were performed with anisotropic displacement para-
meters for non-H atoms. Hydrogen atoms at the phosphorus
atoms in 1 were located in idealized positions and refined
isotropically according to the riding model. In 1, the P2 atoms
and the corresponding carbonyl ligands are disordered, with
a 50% occupancy. In 3, the hexane molecule could not be des-
cribed properly due to disorder. Thus the remaining electron
density was treated with SQUEEZE.23 This procedure gave 32
electrons per void, which is in good accordance with one-half
molecule of hexane.
CCDC-776019 (1), CCDC-776020 (2), CCDC-776021 (3),
and CCDC-776022 (4) contain the supplementary crystallo-
graphic data for this paper. These data can be obtained free of
charge from the Cambridge Crystallographic Data Centre via
http://www.ccdc.cam.ac.uk/products/csd/request/. Details of
the experiments are given in Table 1.
Analytical data of 4: IR (CH2Cl2): ν~CO 2113(w), 2105(w),
2086(m), 2065(vs), 2047(s), 2020(sh), 1952(s), 1919(sh) cm-1
.
Acknowledgment. This work was comprehensively
supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie. The COST
action CM0802 PhoSciNet is gratefully acknowledged.
31P{1H} NMR (161.975 MHz, CD2Cl2): δ 650 (br), 574 (br).
FD-MS: m/z (%) 1215 (100) Mþ. Anal. Calcd for WCo6P2-
C22O22 0.5CH2Cl2: C, 21.48; H, 0.08. Found: C, 21.12; H, 0.46.
X-ray Structure Determination. Data of 1 were collected on
an Oxford Gemini R Ultra diffractometer using Cu KR (λ =
1.54178 A) radiation and of 2, 3, and 4 on a STOE IPDS area
3
Supporting Information Available: This material is available
free of charge via the Internet at http://pubs.acs.org.
˚
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detector diffractometer using Mo KR (λ = 0.71073 A) radiation.
(22) (a) Sheldrick, G. M. Acta Crystallogr. 2008, A64, 112–122. (b)
Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G. L.; Giacovazzo, C.;
Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna, R. J. Appl.
Crystallogr. 1999, 32, 115–119.
(20) SCALE3 ABSPACK, CrysAlis RED software, Version
1.171.31.7; Oxford Diffraction Ltd: Oxford, UK, 2006.
(21) STOE IPDS software, Version 2.89; STOE & CIE GmbH:
Darmstadt, Germany, 1998.
(23) Sluis, P.; Spek, A. L. Acta Crystallogr. 1990, A46, 194–201.