The formation and transformation of metallacycles containing phosphorus or sulfur on molybdenum- or tungsten-cobalt mixed-metal backbones

Article abstract of DOI:10.1039/a906607a

The new heterobimetallic complexes of general formula [{(R′S)Ph₂P}(OC)₂Co{μ-C₂(CO ₂Me)₂}M(η⁵-L)(CO)₂] 1 [L = C₅H₅ or C₅Me₅; M = Mo or W; R′ = hydrocarbyl] undergo thermally induced phosphorus-sulfur bond breaking reactions. By variation of the nature of the R′ substituent, the cyclopentadienyl group or the Group 6 metal centre in 1, bimetallic complexes incorporating bridging four-membered metallacycles of the type M-P-C=C or M-S-C=C (where M = Co, Mo or W), are accessible. While [{(PhS)Ph₂P}(OC)₂Co{μ-C₂(CO ₂Me)₂}Mo(η⁵-C₅H ₅)(CO)₂] 1a gives as the sole product the phosphorus-containing molybdenacyclic species [(OC)(η⁵-C₅H₅)Mo{μ-PPh ₂C(CO₂Me)-C(CO₂Me}(μ-SPh)Co(CO)₂] 2a, the corresponding reaction of [{(R′S)Ph₂P}(OC)₂Co{μ-C₂(CO ₂Me)₂}Mo(η⁵-C₅H ₅)-(CO)₂] (R′ = Buⁿ 1b; Bu^t 1c), results in the formation of both [(OC)(η⁵-C₅H₅)Mo{μ-PPh ₂C(CO₂Me)C(CO₂Me)}-(μ-SR′)Co(CO) ₂] (R′ = Buⁿ 2b; Bu^t 2c) and [(OC)₂Co{μ-SR′C(CO₂Me)C(CO ₂Me)}(μ-PPh₂)Mo(η⁵-C₅H ₅)(CO)] (R′ = Buⁿ 3b; Bu^t 3c). The latter sulfur-containing cobaltacyclic species (3c) has been shown to isomerise to the phosphorus-containing molybdenacyclic species 2c on further heating. Conversely, employment of the pentamethylcyclopentadienyl complex [{(PhS)Ph₂P}(OC)₂Co{μ-C₂(CO ₂Me)₂}Mo(η⁵-C₅Me ₅)(CO)₂] 1b gives three species, [(OC)(η⁵-C₅Me₅)Mo{μ-PPh ₂C(CO₂Me)C(CO₂Me)}(μ-SPh)Co(CO)₂] 2d and [(OC)₂Co{μ-SPhC(CO₂Me)C(CO ₂Me)}-(μ-PPh₂)Mo(η⁵-C₅Me ₅)(CO)] 3d, which are, respectively, analogues of 2a-3c and 3b, 3c, and in addition the phosphorus-containing cobaltacyclic species [(OC)₂Co{μ-PPh₂C(CO₂Me)C(CO ₂Me)}(μ-SPh)Mo(η⁵-C₅Me₅)(CO)] 4d. Thermolysis of [{(BuⁿS)Ph₂P}(OC)₂Co{μ-C₂(CO ₂Me)₂}W(η⁵-C₅H ₅)(CO)₂] 1e, in which a tungsten centre has been introduced in place of the molybdenum in 1b, affords only sulfur-containing metallacyclic products, which incorporate either the cobalt centre as in [(OC)₂Co{μ-SBuⁿC(CO₂Me)C(CO ₂Me)}(μ-PPh₂)W(η⁵-C₅H ₅)(CO)] 3e or the tungsten centre as in [(OC)(η⁵-C₅H₅)W{μ-SBu ⁿC(CO₂Me)C(CO₂Me)}(μ-PPh ₂)Co(CO)₂] 5e. The 'flyover' complex [(OC)(η⁵-C₅H₅)W{μ-C(CO ₂Me)CHC(OMe)O}(μ-SPh)Co(CO){PPh₂(SPh)}] 6 was the only product obtained from the reaction of [(OC)₃Co{μ-C₂(CO₂Me) ₂}W(η⁵-C₅H₅)(CO)₂] with Ph₂P(SPh). Single crystal X-ray diffraction studies have been performed on complexes 1d, 2b, 3c′ [the P(OMe)₃-substituted derivative of 3c], 5e and 6. The Royal Society of Chemistry 1999.

Full text of DOI:10.1039/a906607a

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The formation and transformation of metallacycles containing
phosphorus or sulfur on molybdenum– or tungsten–cobalt
mixed-metal backbones‡
Jason D. King,†a Martin J. Mays,a Giles E. Pateman,a Paul R. Raithby,a Moira A. Rennie,a
Gregory A. Solan,b Nick Choi,c Gráinne Conolec and Mary McPartlinc
a Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge,
UK CB2 1EW
b Department of Chemistry, University of Leicester, University Road, Leicester, UK LE1 7RH
c School of Applied Chemistry, University of North London, Holloway Road, London,
UK N7 8DB
Received 16th August 1999, Accepted 11th October 1999
The new heterobimetallic complexes of general formula [{(RЈS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}M(η5-L)(CO)2] 1
[L = C5H5 or C5Me5; M = Mo or W; RЈ = hydrocarbyl] undergo thermally induced phosphorus–sulfur bond breaking
reactions. By variation of the nature of the RЈ substituent, the cyclopentadienyl group or the Group 6 metal centre in
1, bimetallic complexes incorporating bridging four-membered metallacycles of the type M–P–C᎐C or M–S–C᎐C
᎐
᎐
(where M = Co, Mo or W), are accessible. While [{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-C5H5)(CO)2] 1a gives
as the sole product the phosphorus-containing molybdenacyclic species [(OC)(η5-C5H5)Mo{µ-PPh2C(CO2Me)-
C(CO2Me}(µ-SPh)Co(CO)2] 2a, the corresponding reaction of [{(RЈS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-C5H5)-
(CO)2] (RЈ = Bun 1b; But 1c), results in the formation of both [(OC)(η5-C5H5)Mo{µ-PPh2C(CO2Me)C(CO2Me)}-
(µ-SRЈ)Co(CO)2] (RЈ = Bun 2b; But 2c) and [(OC)2Co{µ-SRЈC(CO2Me)C(CO2Me)}(µ-PPh2)Mo(η5-C5H5)(CO)]
(RЈ = Bun 3b; But 3c). The latter sulfur-containing cobaltacyclic species (3c) has been shown to isomerise to the
phosphorus-containing molybdenacyclic species 2c on further heating. Conversely, employment of the pentamethyl-
cyclopentadienyl complex [{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-C5Me5)(CO)2] 1b gives three species,
[(OC)(η5-C5Me5)Mo{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SPh)Co(CO)2] 2d and [(OC)2Co{µ-SPhC(CO2Me)C(CO2Me)}-
(µ-PPh2)Mo(η5-C5Me5)(CO)] 3d, which are, respectively, analogues of 2a–3c and 3b, 3c, and in addition the
phosphorus-containing cobaltacyclic species [(OC)2Co{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SPh)Mo(η5-C5Me5)(CO)]
4d. Thermolysis of [{(BunS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] 1e, in which a tungsten centre has
been introduced in place of the molybdenum in 1b, affords only sulfur-containing metallacyclic products, which
incorporate either the cobalt centre as in [(OC)2Co{µ-SBunC(CO2Me)C(CO2Me)}(µ-PPh2)W(η5-C5H5)(CO)] 3e
or the tungsten centre as in [(OC)(η5-C5H5)W{µ-SBunC(CO2Me)C(CO2Me)}(µ-PPh2)Co(CO)2] 5e. The ‘flyover’
complex [(OC)(η5-C5H5)W{µ-C(CO2Me)CHC(OMe)O}(µ-SPh)Co(CO){PPh2(SPh)}] 6 was the only product
obtained from the reaction of [(OC)3Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] with Ph2P(SPh). Single crystal X-ray
diffraction studies have been performed on complexes 1d, 2b, 3cЈ [the P(OMe)3-substituted derivative of 3c], 5e and 6.
Mo{PPh2C(CO2Me)C(CO2Me)}(µ-SPh)Co(CO)2] 2a, in which
a PPh2 fragment had been inserted into a molybdenum–carbon
1. Introduction
The chemistry of heterobimetallic transition metal carbonyl
bond in 1a to form a four-membered molybdenacyclic ring
complexes remains an area of continued interest.1–5 The pres-
while the SPh fragment bridged the metal centres (eqn. (1)).6
ence of two distinct metal centres within the same complex
The mechanism by which the above transformation occurs and
presents possibilities for the study of the relative reactivities of
two different metal sites while cooperative interactions between
the two metal centres may lead to complexes possessing unique
reactivity properties.
We have been investigating the reactivity of Group 6–Group
9
alkyne-bridged carbonyl complexes [(OC)3Co(µ-C2R2)-
Mo(η5-C5H5)(CO)2] (R = H, aryl or CO2Me) with a variety of
substituted phosphine ligands capable of undergoing intra-
ligand bond cleavage.6,7 In this earlier work we reported the
reaction of [(OC)3Co{µ-C2(CO2Me)2}Mo(η5-C5H5)(CO)2] with
the thiophosphine ligand, Ph2P(SPh). Preferential substitution
of a carbonyl group at cobalt by the phosphorus centre of the
ligand gave [{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-C5-
H5)(CO)2] 1a and subsequent cleavage of the phosphorus-sulfur
bond led to the regio-specific formation of [(OC)(η5-C5H5)-
notably the apparent migration of the PPh2 fragment from
being cobalt-bound in 1a [as Ph2P(SPh)] to being molybdenum-
bound in 2a is uncertain. Furthermore the incorporation of the
PPh2 rather than the SPh fragment into the four-membered
† Present address: Department of Chemistry, the University of
Montana, Missoula, 59812 Montana, USA.
‡ Supplementary data available: rotatable 3-D crystal structure diagram
in CHIME format. See http://www.rsc.org/suppdata/dt/1999/4447/
J. Chem. Soc., Dalton Trans., 1999, 4447–4456
This journal is © The Royal Society of Chemistry 1999
4447

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Fig. 2 Molecular structure of [{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}-
Mo(η5-C5Me5)(CO)2] 1d.
Fig. 1 Four possible isomeric four-membered metallacyclic ring-
bridged structures obtainable from the thermolysis of [{(RЈS)Ph2P}-
(OC)2Co{µ-C2(CO2Me)2}M(η5-L)(CO)2]
C5Me5; RЈ = Ph, Bun, But).
1 (M = Mo, W; L = C5H5,
The molecular structure of 1d is shown in Fig. 2; Table 2 lists
selected bond distances and angles. The structure consists of a
(OC)2CoMo(CO)2 skeleton which is bridged by an unsaturated
alkyne unit [µ-C2(CO2Me)2] which lies almost perpendicular to
the single Co–Mo bond [2.715(1) Å]10,11 in a manner similar to
that in a number of previously reported such complexes.12 The
cobalt atom is further coordinated by a Ph2P(SPh) ligand,
which bonds via the phosphorus atom and thus completes a
distorted octahedral arrangement about the cobalt centre. The
molybdenum atom is additionally coordinated by a penta-
methylcyclopentadienyl ligand, again completing a distorted
octahedral arrangement about the molybdenum centre. The
Ph2P(SPh) and the pentamethylcyclopentadienyl groups are
orientated in a ‘sawhorse’ configuration about the Co–Mo
bond, occupying pseudo-axial sites on each metal centre
[Mo–Co–P 148.81(7)Њ, Co–Mo–(C5Me5)centroid 122.1Њ].
The spectroscopic properties of 1 are all in accord with those
of previously reported examples of mono-phosphine substi-
tuted Group 6–Group 9 alkyne-bridged complexes.6,7,12 The
pentamethylcyclopentadienyl species 1d displays slightly lower
frequency carbonyl absorption bands in the IR spectrum con-
sistent with better electron donating capability of the C5Me5
over the C5H5 group.
metallacycle was unexpected, given our observations in the
related dicobalt chemistry that it is the SRЈ rather than the PPh2
fragment that is preferentially incorporated.8,9
In this paper we report the preparation of new Group 6-
Group 9 alkyne-bridged complexes of the type [{(RЈS)Ph2P}-
(OC)2Co{µ-C2(CO2Me)2}M(η5-L)(CO)2] (M = Mo, W; L =
C5H5, C5Me5; RЈ = alkyl) 1. It was envisaged that changing the
electronic and steric properties of 1 by varying the nature of
(i) the substituent RЈ on the thiophosphine ligand, (ii) the
cyclopentadienyl ligand or (iii) the Group 6 metal centre, could
help elucidate the mechanism of formation of 2a from 1a (see
eqn. (1)) and that thermolysis of the new complexes might also
yield other metallacyclic products of the type 3–5 (Fig. 1). This
expectation has been realised and we now report that all four of
the isomeric four-membered ring-bridged structures shown in
Fig. 1 can be obtained.
2. Results and discussion
(a) Preparation of [{(RЈS)Ph2P}(OC)2Co{ꢀ-C2(CO2Me)2}M(ꢁ5-
L)(CO)2] (M ؍ Mo, W; L ؍ C5H5, C5Me5; RЈ ؍ hydrocarbyl) 1
(b) Thermolysis of thiophosphine-substituted species 1
The complexes [{(RЈS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}M(η5-
L)(CO)2] (RЈ = Bun, M = Mo, L = C5H5 1b; RЈ = But, M = Mo,
L = C5H5 1c; RЈ = Ph, M = Mo, L = C5Me5 1d; RЈ = Bun,
M = W, L = C5H5 1e) have been prepared in high yield from
the reaction of [(OC)3Co{µ-C2(CO2Me)2}M(η5-L)(CO)2] with
Ph2P(SRЈ) at ca. 313 K (eqn. (2)). All the complexes have been
The complexes 1 all undergo thermally induced phosphorus–
sulfur bond breaking reactions. By variation of the nature of (i)
the RЈ group of the coordinated thiophosphine group, (ii) the
cyclopentadienyl ligand or (iii) the Group 6 metal centre in 1,
complexes belonging to all the structural types illustrated in
Fig. 1 (2–5) have been identified.
The ordering of Co and Mo/W in the chemical formulae will,
throughout this account, indicate the orientation of the bridg-
ing ligand. That is, when the α-carbon of the substituted alkenyl
ligand [C(CO2Me)C(CO2Me)SRЈ or C(CO2Me)C(CO2Me)-
PPh2] is σ-bonded to Mo/W rather than Co, then Mo/W will
precede Co in the ordering of the formula and vice versa.
(i) Variation of the RЈ group. The thermolysis of [(OC)2(η5-
C5H5)Mo{µ-C2(CO2Me)2}Co(CO)2{PPh2(SRЈ)}] (RЈ = Bun 1b;
But 1c) in toluene at 363
K
gives [(OC)(η5-C5H5)Mo-
{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SRЈ)Co(CO)2] (RЈ = Bun 2b;
But 2c) and [(OC)2Co{µ-SRЈC(CO2Me)C(CO2Me)}(µ-PPh2)-
Mo(η5-C5H5)(CO)] (RЈ = Bun 3b; But 3c) respectively in high
combined yield (Scheme 1a). These complexes have been char-
acterised by 1H, 13C, 31P NMR and IR spectroscopy, mass spec-
trometry and by microanalysis (see Table 1 and Experimental
section). In addition complex 2b has been the subject of a single
crystal X-ray diffraction study.
1
characterised by H, 13C, 31P NMR, IR spectroscopy and by
mass spectrometry (see Table 1 and Experimental section).
Complex 1d has additionally been the subject of a single crystal
X-ray diffraction study.
The molecular structure of complex 2b including the atom
numbering scheme is depicted in Fig. 3 and selected bond dis-
4448
J. Chem. Soc., Dalton Trans., 1999, 4447–4456

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Table 1 Infrared, 1H and 31P NMR data for the new complexes 1–6
Compound
ν(CO)a/cmϪ1
1H NMR (δ)c
31P NMR (δ)d
1b
1c
1d
1e
2b
2c
2d
3b
2031m, 2001vs,
1975s, 1705m
2030s, 1999vs,
1975s, 1708m
2018s, 1984s,
1954s, 1693m
2025s, 1991vs,
1962vs,1694mb
2017s, 1971s,
1934w, 1693m
2029s, 1978s,
1935w, 1693m
2001s, 1957s,
1918w, 1684m
2029vs, 1980vs,
1936s, 1682s,
1668m
7.9–7.2 [m, 10H, Ph], 5.36 [s, 5H, C5H5], 3.34 [s, 6H, (CO2Me)2],
2.2–0.7 [s, 9H, Bun]
Ϫ65.1 [s, Co–PPh2(SBun)]
Ϫ54.7 [s, Co–PPh2(SBut)]
Ϫ50.8 [s, Co–PPh2(SPh)]
Ϫ75.5 [s, Co–PPh2(SBun)]
7.9–7.0 [m, 10H, Ph], 5.28 [s, 5H, C5H5], 3.35 [s, 6H, (CO2Me)2], 1.28
[s, 9H, But]
7.6–6.8 [m, 15H, Ph], 3.43 [s, 6H, (CO2Me)2], 1.87 [s, 15H, C5Me5],
1.23 [s, 9H, But]
7.6–7.0 [m, 10H, Ph], 5.30 [s, 5H, C5H5], 3.30 [s, 6H, (CO2Me)2], 2.8
[m, 2H, CH2], 1.9 [m, 2H, CH2], 1.2 [m, 2H, CH2], 0.9 [m, 3H, Me]
7.8–7.2 [m, 10H, Ph], 4.95 [s, 5H, C5H5], 3.75 [s, 3H, CO2Me], 3.39 Ϫ146.7 [s, Mo–PPh2C2(CO2Me)2]
[s, 3H, (CO2Me)], 2.2–0.9 [s, 9H, Bun]
8.0–7.2 [m, 10H, Ph], 4.89 [s, 5H, C5H5], 3.78 [s, 3H, CO2Me], 3.56 Ϫ147.0 [s, Mo–PPh2C2(CO2Me)2]
[s, 3H, CO2Me], 1.21 [s, 9H, But]
7.7–7.0 [m, 15H, Ph], 3.81 [s, br, 3H, CO2Me], 3.56 [s, br, 3H,
CO2Me], 1.63 [s, 15H, C5Me5]
Ϫ146.7 [s, Mo–PPh2C2(CO2Me)2]
7.9–7.2 [m, 10H, Ph], 5.31 [s, 5H, C5H5], 3.54 [s, 3H, CO2Me], 2.79
24.9 [s, µ-PPh2]
[s, 3H, CO2Me], 2.2–0.9 [s, 9H, Bun]
3c
2026s, 1982s,
1927m, 1682m
1966s, 1913s,
1675m
2015s, 1965s,
1919w, 1676m
2025s, 1981s,
1923m, 1681m
7.6–7.0 [m, 10H, Ph], 5.25 [s, 5H, C5H5], 3.57 [s, 3H, CO2Me], 2.85
[s, 3H, CO2Me], 1.38 [s, 9H, But]
33.6 [s, µ-PPh2]
3cЈ
3d
3e
7.9–7.2 [m, 10H, Ph], 5.31 [s, 5H, C5H5], 3.67 [d, 3J(PH) 12, 9H,
P(OMe)3], 3.54 [s, 3H, Me], 2.79 [s, 3H, Me], 1.36 [s, 9H, But]
not recorded
35.1 [s, µ-PPh2], Ϫ1.2 [s, Co–P(OMe)3]
59.4 [s, µ-PPh2]
7.5–7.1 [m, 10H, Ph], 5.40 [s, 5H, C5H5], 3.61 [s, br, 3H, CO2Me],
3.30 [s, br, 3H, CO2Me], 2.4 [m, 2H, CH2], 1.6 [m, 2H, CH2], 1.4 [m,
2H, CH2], 0.9 [m, 3H, Me]
Ϫ14.8 [s, µ-PPh2]
4d
5e
2011s, 1970s,
1918w, 1679m
2025s, 1981s,
1966m, 1681m
7.8–7.1 [m, 15H, Ph], 3.63 [s, br, 3H, CO2Me], 2.76 [s, br, 3H,
CO2Me], 1.58 [s, 15H, C5Me5]
7.5–7.1 [m, 10H, Ph], 5.4 [s, 5H, C5H5], 3.6 [s, br, 3H, CO2Me], 3.3
[s, br, 3H, CO2Me], 2.4 [m, 2H, CH2], 1.6 [m, 2H, CH2], 1.4 [m, 2H,
CH2], 0.9 [m, 3H, Me]
Ϫ160.1 [s, Co–PPh2C2(CO2Me)2]
Ϫ32.0 [s, µ-PPh2]
6
1980s, 1923s,
7.9–7.0 [m, 20H, Ph], 5.29 [s, 5H, C5H5], 3.71 [s, br, CO2Me], 3.48
[s, br, 3H, CO2Me]
Ϫ44.0 [s, Co–PPh2(SPh)]
1666m,1504mb
a Recorded in n-hexane solution. b Recorded in CH2Cl2 solution. c 1H chemical shifts (δ) in ppm relative to SiMe4 (δ 0.0), coupling constants in Hz in
CDCl3 at 293 K. d 31P chemical shifts (δ) in ppm relative to external P(OMe)3 (δ 0.0) (upfield shifts negative). Add 140.2 to tabulated values in order to
reference relative to external 85% H3PO4. Spectra were {1H}-gated decoupled and measured in CDCl3 at 293 K.
Scheme 1 Products from the thermolysis of 1b–e; effects of varying the nature of (a) RЈ, (b) the cyclopentadienyl group and (c) Group 6 metal
centre. [Co] = Co(CO)2.
tances and angles are listed in Table 3. The Mo–Co single bond
[2.633(1) Å]10 is bridged by a n-butylthiolato fragment and by a
vinyl-phosphide group, in which the vinyl group is σ-bonded to
the molybdenum [Mo–C(1) 2.183(8) Å] and asymmetrically
π-bound to the cobalt [Co–C(4) 2.064(8); Co–C(1) 1.917(8) Å].
The β-substituent of the vinyl group is a diphenylphosphide
J. Chem. Soc., Dalton Trans., 1999, 4447–4456
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Table 2 Selected bond distances (Å) and angles (Њ) for complex
[{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-C5Me5)(CO)2] 1d
Mo(1)–Co(1)
Mo(1)–C(7)
Co(1)–C(7)
P(1)–C(27)
P(1)–S(1)
C(7)–C(8)
C(6)–C(7)
C(9)–O(8)
C(6)–O(5)
2.715(1)
2.163(7)
1.945(7)
1.816(7)
2.129(3)
1.360(9)
1.46(1)
Mo(1)–C(8)
Co(1)–C(8)
Co(1)–P(1)
P(1)–C(33)
S(1)–C(21)
C(9)–C(8)
C(9)–O(7)
C(6)–O(6)
2.138(7)
1.970(7)
2.227(2)
1.844(8)
1.808(8)
1.47(1)
1.210(8)
1.195(8)
1.334(8)
1.346(9)
Mo–C(carbonyl)
Co–C(carbonyl)
2.005(9)–
2.01(1)
1.776(8)–
1.789(9)
C–O(Mo-carbonyl) 1.123(9)–
1.140(8)
C–O(Co-carbonyl) 1.146(8)–
1.148(8)
Co(1)–Mo(1)–C(8)
Co(1)–Mo(1)–C(4)
C(8)–Mo(1)–C(7)
C(8)–Mo(1)–C(3)
C(7)–Mo(1)–C(3)
Mo(1)–Co(1)–C(8)
46.0(2)
88.3(2)
36.9(2)
78.8(3)
89.8(3)
51.3(2)
Co(1)–Mo(1)–C(7)
Co(1)–Mo(1)–C(3) 124.6(2)
C(8)–Mo(1)–C(4)
C(7)–Mo(1)–C(4)
C(4)–Mo(1)–C(3)
Mo(1)–Co(1)–C(7)
45.3(2)
Fig.
3
Molecular structure of [(OC)(η5-C5H5)Mo{µ-PPh2C(CO2-
Me)C(CO2Me)}(µ-SBun)Co(CO)2] 2b. Hydrogen atoms omitted for
80.3(2)
116.2(3)
86.3(4)
52.2(2)
clarity.
system with one sharp upfield singlet resonance at δ Ϫ146.7 for
2b and Ϫ147.0 for 2c [relative to P(OMe)3 (δ 0.0)] indicative of
the phosphorus atom of the ligand being directly bonded to the
molybdenum rather than to the quadrupolar 59Co atom.
Mo(1)–Co(1)–P(1) 148.81(7)
Mo(1)–Co(1)–C(1) 107.7(2)
MO(1)–Co(1)–C(2)
P(1)–Co(1)–C(7)
P(1)–Co(1)–C(2)
C(8)–Co(1)–C(1)
C(8)–Co(1)–C(2)
C(1)–Co(1)–C(2)
S(1)–P(1)–C(27)
C(7)–C(8)–Co(1)
C(8)–C(7)–Co(1)
Mo(1)–C(8)–Co(1)
92.1(2)
107.1(2)
100.0(2)
138.9(3)
111.8(3)
102.9(4)
102.5(2)
68.7(4)
P(1)–Co(1)–C(8)
P(1)–Co(1)–C(1)
C(8)–Co(1)–C(7)
C(7)–Co(1)–C(1)
C(7)–Co(1)–C(2)
C(27)–P(1)–C(33)
S(1)–P(1)–C(33)
C(7)–C(8)–Mo(1)
C(8)–C(7)–Mo(1)
Mo(1)–C(7)–Co(1)
97.5(2)
97.6(3)
40.7(3)
98.3(3)
142.9(3)
107.1(4)
103.1(3)
72.6(4)
70.6(4)
82.6(3)
The structures of complexes 3b and 3c have also been assigned
on the basis of the spectroscopic data. The 31P-{1H} NMR
spectra are consistent with the presence of bridging phosphido
groups with the breadth of the singlet downfield resonance
observed in both cases [δ 24.9 3b, 33.6 3c] being due to the direct
bonding of the phosphorus atom of the ligand to the quadru-
polar 59Co metal centre. In the 13C-{1H} NMR spectra of 3b, in
addition to cyclopentadienyl, phenyl and butyl resonances,
three carbonyl resonances are observed; one at a higher chem-
ical shift (ca. δ 230) is typical of molybdenum-bound carbonyl
groups4,6,7 and two broad signals at lower chemical shifts (ca.
δ 208 and 201) are characteristic of Co-bound carbonyl
groups.6,7,18 For 3b and 3c the unsaturated olefinic carbon atoms
are observed as singlets between δ 100 and 90 [µ-SRC(CO2Me)-
C(CO2Me)] and between δ 50 and 30 [µ-SRC(CO2Me)C-
(CO2Me)] with the carboxylate carbonyl groups giving separate
resonances at ca. δ 176 and 173. The inequivalence of the carb-
oxylate substituents on the olefinic carbon atoms is further
indicated by the observation of two carboxylate-methyl reson-
ances in the 1H NMR spectra [δ 3.54, 2.79 3b; 3.57, 2.85 3c].
Although single crystals of neither 3b nor 3c could
be obtained, the P(OMe)3-substituted derivative of 3c,
[{(MeO)3P}(OC)Co{µ-SButC(CO2Me)C(CO2Me)}(µ-PPh2)-
Mo(η5-C5H5)(CO)] 3cЈ, prepared by treatment of 3c with
P(OMe)3 at room temperature (eqn. (3)), was crystallised and
subjected to a single crystal X-ray diffraction study.
70.7(4)
82.6(3)
Table 3 Selected bond distances (Å) and angles (Њ) for [(OC)(η5-
C5H5)Mo{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SBun)Co(CO)2] 2b
Co–Mo
Mo–P(1)
Co–S(1)
C(4)–P(1)
C(5)–C(4)
P(1)–C(11)
C(5)–O(5)
C(5)–O(6)
C(2)–O(2)
C(3)–O(3)
2.633(1)
2.476(2)
2.227(3)
1.775(8)
1.46(1)
1.822(6)
1.21(1)
1.33(1)
1.20(1)
1.46(1)
Mo–S(1)
Mo–C(1)
Co–C(4)
2.433(3)
2.183(8)
2.064(8)
1.917(8)
1.48(1)
1.46(1)
1.810(6)
1.43(1)
1.32(1)
1.81(1)
Co–C(1)
C(1)–C(2)
C(1)–C(4)
P(1)–C(21)
C(6)–O(6)
C(2)–O(3)
S(1)–C(7)
Mo–C(carbonyl)
C–O(Mo-carbonyl) 1.12(1)
2.04(1)
Co–C(carbonyl)
1.77(1)–1.78(1)
C–O(Co-carbonyl) 1.14(1)–1.16(1)
Co–Mo–S(1)
P(1)–Mo–S(1)
C(1)–Mo–S(1)
C(41)–Mo–Co
S(1)–Co–Mo
P(1)–Co–S(1)
C(1)–Co–Mo
C(61)–Co–Mo
Co–P(1)–Mo
Co–C(1)–Mo
52.0(1)
122.0(1)
74.2(2)
84.4(3)
59.4(1)
111.9(1)
54.6(2)
107.8(3)
57.5(1)
79.6(3)
Co–Mo–P(1)
Co–Mo–C(1)
C(1)–Mo–P(1)
C(31)–Mo–Co
P(1)–Co–Mo
C(4)–Co–S(1)
C(51)–Co–Mo
Co–S(1)–Mo
Co–C(4)–Mo
70.0(1)
45.7(2)
65.1(2)
153.8(2)
52.5(1)
125.3(2)
148.0(3)
68.6(1)
61.3(2)
group which is itself coordinated to the molybdenum [Mo–P(1)
2.476(2) Å], thus forming a four-membered metallacyclic system
[Mo–C᎐C–P]. Similar ‘flyover’ ligands have been structurally
᎐
characterised in other di- and tri-nuclear systems (Ni–Fe,13 Ru–
Co,14 Ru3,15 Mo2,16 W217), and indeed in the structurally related
species [(OC)(η5-C5H5)Mo(µ-PPh2CPhCH)(µ-SPh)Co(CO)2].7
The structure of 2c has been assigned on the basis of the
close similarity in the spectroscopic data with those for the
structurally characterised complex 2b. The IR spectra of both
2b and 2c display, in addition to three terminal νCO bands, a νCO
carboxylate band at ca. 1693 cmϪ1. The 31P-{1H} NMR spectra
of these complexes are in each case consistent with the presence
of a diphenylphosphide group forming part of a metallacyclic
The molecular structure of 3cЈ including the atom numbering
scheme is illustrated in Fig. 4; Table 4 lists selected bond dis-
tances and angles. The Mo–Co single bond [2.717(1) Å],10 is
bridged by a diphenylphosphido group and by a vinyl group
4450
J. Chem. Soc., Dalton Trans., 1999, 4447–4456

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Table 4 Selected bond distances (Å) and angles (Њ) for complex
[{(MeO)3P}(OC)Co{µ-SButC(CO2Me)C(CO2Me)}(µ-PPh2)Mo(η5-C5-
H5)(CO)] 3cЈ
carbonyl group. A noteworthy feature exhibited by the P(OMe)3
ligand is its inclination away from the axial position (pseudo-
trans to the metal–metal bond) normally adopted by phosphine
ligands [Mo–Co–P(1) 122.32(6)Њ] in organo-bridged substituted
bimetallic carbonyl complexes.7,8,19 The explanation for this
distortion is uncertain but it is accompanied by an elongation
of the Co–S(1) bond [2.346(2) Å]20 presumably to avoid any
steric interaction between the tert-butyl substituent of the thio-
late group and the methoxy substituents of the phosphite. To
the knowledge of the authors there are few examples other than
3cЈ of structurally characterised bimetallic complexes that
incorporate a µ-SRCRCR ligand.22
Co(1)–Mo(1)
Mo(1)–C(1)
Co(1)–S(1)
Co(1)–P(1)
C(1)–S(1)
2.717(1)
2.212(6)
2.346(2)
2.159(2)
1.800(6)
1.485(9)
1.856(6)
1.590(5)
1.613(5)
Mo(1)–P(2)
Mo(1)–C(4)
Co(1)–P(2)
Co(1)–C(4)
C(1)–C(4)
C(4)–C(5)
P(2)–C(31)
P(1)–O(10)
S(1)–C(12)
2.401(2)
2.132(6)
2.209(2)
2.014(6)
1.434(9)
1.463(9)
1.816(6)
1.592(5)
1.903(7)
C(1)–C(2)
P(2)–C(21)
P(1)–O(9)
P(1)–O(11)
The observation that two isomeric products (2b/3b and 2c/3c)
are obtained respectively from the thermal reaction of 1b or 1c
is in contrast to the outcome of the corresponding reaction of
1a in which only 2a was obtained. When 3c was refluxed in
toluene, 2c was obtained in high yield (Scheme 1a), suggesting
that 3 may be an intermediate in the formation of 2. The mech-
anism for the transformation of 3 to 2 is uncertain but Scheme
2 shows a possible pathway. It is suggested that initial cleavage
Mo(1)–C(carbonyl) 1.953(8)
C–O(Mo-carbonyl) 1.154(8)
Co(1)–C(carbonyl) 1.759(7)
C–O(Co-carbonyl) 1.145(8)
Co(1)–Mo(1)–P(2)
Co(1)–Mo(1)–C(4)
C(7)–Mo(1)–C(4)
C(4)–Mo(1)–C(1)
C(7)–Mo(1)–P(2)
50.67(4)
47.2(2)
76.8(3)
38.5(2)
97.3(2)
Co–Mo–C(1)
Co–Mo–C(7)
C(7)–Mo–C(1)
C(4)–Mo–P(2)
C(1)–Mo–P(2)
Mo–Co–P(2)
62.7(2)
115.9(2)
94.4(3)
79.0(2)
110.5(2)
57.22(2)
137.6(2)
96.9(2)
Mo(1)–Co(1)–P(1) 122.32(6)
Mo(1)–Co(1)–C(4)
Mo(1)–Co(1)–S(1)
C(8)–Co(1)–C(4)
C(8)–Co(1)–P(2)
P(1)–Co(1)–P(2)
C(4)–Co(1)–S(1)
P(2)–Co(1)–S(1)
O(9)–P(1)–O(11)
C(21)–P(2)–C(31)
C(1)–S(1)–Co(1)
C(1)–C(4)–Co(1)
Co(1)–C(4)–Mo(1)
51.0(2)
76.90(5)
92.6(3)
106.5(2)
96.95(7)
74.3(2)
131.87(7)
97.7(3)
99.0(3)
76.5(2)
96.5(4)
81.8(2)
Mo–Co–C(8)
C(8)–Co–P(1)
C(4)–Co(1)–P(1)
C(4)–Co(1)–P(2)
C(8)–Co(1)–S(1)
P(1)–Co(1)–S(1)
O(9)–P(1)–O(10)
O(10)–P(1)–O(11)
Co(1)–P(2)–Mo(1)
S(1)–C(1)–Mo(1)
C(1)–C(4)–Mo(1)
168.7(2)
86.3(2)
117.7(2)
95.70(7)
106.4(3)
103.4(3)
72.11(6)
103.5(3)
73.7(3)
Scheme 2 Possible pathway for the isomerisation of 3c to give 2c.
Terminal carbonyl groups omitted for clarity.
of the S–C bond in 3 gives intermediate A, which contains a
pendant thiolate group and a bridging alkyne. Attack of the
thiolate group at the molybdenum centre could displace the
bridging phosphido group from the cobalt centre (see inter-
mediate B) and insertion of the resulting pendant phosphide
into an alkyne carbon–molybdenum bond would then yield
complex 2. This thermally-induced isomerisation reaction can
be compared to the organophosphine-induced transformation
of [Co2{µ-SPhC(O)CHCH}(µ-PPh2)(CO)4] to [Co2{µ-PPh2-
CHCHC(O)}(µ-SPh)(CO)2(L)2] (L = phosphite or phosphine)
in which a five-membered thiolate-containing metallacycle is
converted to a five-membered phosphide-containing metalla-
cyclic species.8
(ii) Variation in the cyclopentadienyl substituent. In the
previous sub-section the introduction of an alkyl-thiolate group
(1b, 1c) in place of the aryl-thiolate in 1a resulted in the
isolation of analogues (3b, 3c) of a possible intermediate in the
formation of 2a. This effect on the reaction products of
replacing an aryl substituent on sulfur with an alkyl substituent
suggested that it would be worthwhile to probe the effect of
changing the nature of the cyclopentadienyl substituent on the
thermally induced phosphorus–sulfur bond cleavage reaction.
Accordingly, the thermolysis of the pentamethylcyclopenta-
dienyl species [{(PhS)Ph2P}(OC)2{µ-C2(CO2Me)2}Mo(η5-C5-
Me5)(CO)2] 1d in toluene at 383 K was undertaken. Three
products are isolated: [(OC)(η5-C5Me5)Mo{µ-PPh2C(CO2Me)-
C(CO2Me)}(µ-SPh)Co(CO)2] 2d, [(OC)2Co{µ-SPhC(CO2Me)-
C(CO2Me)}(µ-PPh2)Mo(η5-C5Me5)(CO)] 3d and [(OC)2Co-
{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SPh)Mo(η5-C5Me5)(CO)] 4d
Fig. 4 Molecular structure of [{(MeO)3P}(OC)Co{µ-SButC(CO2-
Me)C(CO2Me)}(µ-PPh2)Mo(η5-C5H5)(CO)] 3cЈ. Hydrogen atoms
omitted for clarity. The methyl group of the disordered OMe substituent
was assigned two sites of 50% occupancy.
which is σ-bonded to the cobalt [Co–C(4) 2.014(6) Å] and
asymmetrically π-bound to the molybdenum [Mo–C(1)
2.212(6), Mo–C(4) 2.132(6) Å]. The β-substituent of the vinyl
group is a tert-butylthiolate group which is itself coordinated to
the cobalt, forming a four-membered metallacyclic system [Co–
C᎐C–S]. The coordination sphere of the molybdenum centre is
᎐
completed by a cyclopentadienyl group and a carbonyl group
while the cobalt centre is bound by a P(OMe)3 group and a
J. Chem. Soc., Dalton Trans., 1999, 4447–4456
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Table 5 Selected bond distances (Å) and angles (Њ) for complex
[(OC)(η5-C5H5)W{µ-SBunC(CO2Me)C(CO2Me)}(µ-PPh2)Co(CO)2] 5e
(Scheme 1b). All three complexes have been characterised by
1H, 13C, 31P NMR, IR spectroscopy and by mass spectrometry
(see Table 1 and Experimental section).
W–Co
W–C(1)
Co–P(1)
Co–C(4)
P(1)–C(21)
S(1)–C(7)
C(1)–C(4)
C(3)–O(3)
C(5)–O(6)
C(2)–O(3)
2.662(2)
2.19(1)
2.193(3)
2.03(1)
1.85(1)
1.83(1)
1.46(2)
1.46(2)
1.37(2)
1.31(2)
W–P(1)
W–S(1)
2.406(3)
2.522(3)
1.95(1)
1.823(8)
1.79(1)
1.47(2)
1.48(2)
1.16(2)
1.19(2)
The IR spectrum of 3d is similar to that of other complexes
of type 3 with the carbonyl absorptions in 3d shifted to lower
frequency by ca. 10–25 cmϪ1. The 31P-{1H} NMR spectrum of
3d is consistent with the presence of a bridging phosphido
group, displaying a single broad resonance at δ 59.4. The
13C-{1H} NMR spectrum shows, in addition to signals attribut-
able to the phenyl and pentamethylcyclopentadienyl carbon
atoms, singlet resonances corresponding to each of the carb-
oxylate carbonyl groups [µ-SPhC(CO2Me)C(CO2Me)] (δ 177.6,
175.3). Additionally, the olefinic carbon σ-bonded to cobalt
[µ-SPhC(CO2Me)C(CO2Me)] is observed at δ 106.2, with the
inequivalent carboxylate methyl carbon resonances at δ 53.7
and δ 51.1.
For the complex [(OC)2Co{µ-PPh2C(CO2Me)C(CO2Me)}(µ-
SPh)Mo(η5-C5Me5)(CO)] 4d the IR spectrum displays a similar
pattern of νCO absorptions to that of the phosphido-bridged
cyclopentadienyl analogue [(OC)2Co{µ-PPh2C(CO2Me)C(CO2-
Me)}(µ-PPh2)Mo(η5-C5H5)(CO)]6 although the bands are
shifted to lower wavenumber. The 31P-{1H} NMR spectrum of
4d shows a broad upfield singlet [δ Ϫ160.1] confirming that the
phosphido group is incorporated into a four-membered metal-
Co–C(1)
P(1)–C(11)
S(1)–C(4)
C(1)–C(2)
C(4)–C(5)
C(5)–O(5)
C(2)–O(2)
W–C(carbonyl) 1.96(1)
Co–C(carbonyl) 1.78(2)–1.78(1)
C–O(carbonyl) 1.17(2)
C–O(carbonyl) 1.12(2)–1.15(2)
P(1)–W–Co
S(1)–W–P(1)
C(1)–W–P(1)
C(41)–W–Co
S(1)–Co–W
C(1)–Co–W
C(51)–Co–W
Co–P(1)–W
Co–C(1)–W
51.0(1)
126.5(1)
79.1(3)
82.8(4)
50.1(1)
54.0(3)
143.7(5)
70.6(1)
79.9(4)
S(1)–W–Co
C(1)–W–Co
C(1)–W–S(1)
P(1)–Co–W
S(1)–Co–P(1)
C(4)–Co–W
C(61)–Co–W
Co–S(1)–W
75.8(1)
46.2(3)
65.4(3)
58.5(1)
108.4(1)
72.5(3)
112.3(4)
54.1(1)
lacycle [Co–P–C᎐C] and is coordinated to the quadrupolar
᎐
59Co atom. The 13C-{1H} NMR spectrum of 4d shows, in addi-
tion to pentamethylcyclopentadienyl and phenyl signals, reson-
ances corresponding to ester groups, [C(CO2Me)C(CO2Me),
δ 176.0 and 171.1 and C(CO2Me)C(CO2Me), δ 50.9 and 50.7].
In addition, a singlet at δ 106.2 [µ-PPh2C(CO2Me)C(CO2Me)]
and a doublet at δ 31.3 [1J(PC) 42, µ-PPh2C(CO2Me)C(CO2-
Me)] are displayed.
In the IR spectrum of [(OC)(η5-C5Me5)Mo{µ-PPh2C(CO2-
Me)C(CO2Me)}(µ-SPh)Co(CO)2] 2d a similar pattern of νCO
absorption bands to that of the cyclopentadienyl complexes
2a–c is observed although shifted to lower wavenumber by ca.
10 cmϪ1.6 The 31P-{1H} NMR spectrum displays a sharp singlet
at δ Ϫ146.7, typical of a phosphide group contained within a
four-membered molybdacyclic ring [Mo–P–C᎐C]. The 1H NMR
Fig. 5 Molecular structure of [(OC)2Co{µ-SBunC(CO2Me)C(CO2-
Me)}(µ-PPh2)W(η5-C5H5)(CO)] 5e. Hydrogen atoms omitted for
clarity.
᎐
spectrum of 2d shows, in addition to pentamethylcyclopenta-
dienyl and phenyl resonances, signals corresponding to the two
carboxylate-methyl groups at δ 3.81 and 3.56, confirming that
the two carboxylate groups are inequivalent.
analysis (see Table 1 and Experimental section). Further-
more, complex 5e has been the subject of a single crystal X-ray
structure determination study.
While the thermolytic reaction of 1a was found to give
uniquely 2a and that of 1b and 1c to give both 2b/3b and 2c/3c,
the corresponding reaction of 1d affords three products. Two
of these products, 2d and 3d are analogous to the products
obtained on the thermolysis of 1b and 1c. The third product,
which is obtained in the highest yield, is the phosphorus-
containing cobaltacyclic species 4d and this has no analogue in
the other reactions studied. It seems that the presence of the
η5-C5Me5 group increases the tendency of the metallacycle to
incorporate the Group 9 metal centre. The reason may be that
the greater steric bulk of the η5-C5Me5 group on the molyb-
denum atom causes the bulky phenylthiolate or diphenylphos-
phido groups of the metallacycle to coordinate preferentially to
the metal atom not bearing the η5-C5Me5 group.
The molecular structure of 5e is shown in Fig. 5 and
Table 5 lists selected bond distances and angles. The structure
reveals a W–Co single bond [2.662(2) Å],21 bridged both by
a diphenylphosphido group and by a vinylthiolate ligand
which is σ-bonded to the tungsten [W–C(1) 2.19(1) Å] and
asymmetrically π-bound to the cobalt [Co–C(1) 1.95(1), Co–
C(4) 2.03(1) Å]. The β-substituent of the vinyl group is a n-
butylthiolate group which is itself coordinated to the tungsten
atom [W–S(1) 2.522(3) Å], thus forming a four-membered
metallacyclic system [W–C᎐C–S]. Structurally characterised
᎐
bimetallic complexes incorporating a µ-SRCRCR ligand have
been observed in only a few cases22 which include 3cЈ (see
Fig. 4). The smaller covalent radius of cobalt compared to
tungsten accounts for the asymmetric bridging of the two
metal centres in 5e by the phosphido ligand [W–P(1) 2.406(3)
vs. Co–P(1) 2.193(3) Å].
(iii) Effect of tungsten in place of molybdenum in 1. Cobalt–
tungsten systems are generally more kinetically inert and
stable than their cobalt–molybdenum analogues, undergoing
reactions over a longer time-scale and at higher temperatures17
so it was of interest to examine the thermal reaction of
[{(BunS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] 1e.
Thermolysis of le in toluene at 373 K gives the complexes
[(OC)2Co{µ-SBunC(CO2Me)C(CO2Me)}(µ-PPh2)W(η5-C5H5)-
(CO)] 3e and [(OC)(η5-C5H5)W{µ-SBunC(CO2Me)C(CO2Me)}-
(µ-PPh2)Co(CO)2] 5e in relatively high combined yield (Scheme
The 31P-{1H} NMR spectrum of 5e is consistent with a
bridging diphenylphosphido group showing a broad singlet
resonance [δ Ϫ32.0] while the 13C-{1H} NMR spectrum shows,
in addition to cyclopentadienyl and thiolate signals, three carb-
onyl resonances. One, at higher chemical shift, is split into a
2
doublet [δ 231.4, J(PC) 9] and is typical of a tungsten-bound
carbonyl3 while two broad resonances at lower chemical shift
[δ 210.2 and 207.2] are typical of cobalt-bound carbonyl
groups.
1
1c). Both complexes have been characterised by H, 31P, 13C
NMR, IR spectroscopy and by mass spectrometry and micro-
4452
J. Chem. Soc., Dalton Trans., 1999, 4447–4456

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Table 6 Selected bond distances (Å) and angles (Њ) for complex
The structure of complex 3e is assigned on the basis of a
comparison of the spectroscopic data with those of other com-
plexes of type 3. The 31P-{1H} NMR spectrum shows a broad
singlet resonance at δ Ϫ14.8 consistent with a bridging phos-
phido group. The inequivalence of the ester functionalities on
the vinyl group is supported by distinct carboxylate carbonyl
group resonances in the 13C-{1H} NMR spectrum along with
separate signals for the two carboxylate-methyl groups at δ 3.61
and 3.30 in the 1H NMR spectrum.
The products obtained from phosphorus–sulfur bond cleav-
age on thermolysis of the Co–W system 1e show a notable
difference from the Co–Mo system. While preferential form-
ation of metallacycles incorporating the phosphide fragment is
observed for the Co–Mo systems 1a–d the Co–W system 1e
leads exclusively to metallacycles incorporating the thiolate
fragment. More significantly, the phenylthiolate analogue of 1e,
[{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] 1f
could not be prepared. Indeed on reaction of [(OC)3Co-
{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] with Ph2P(SPh) at 373 K
for 24 h the only product isolated was [(OC)(η5-C5H5)W-
{µ-C(CO2Me)CHC(OMe)O}(µ-SPh)Co(CO){PPh2(SPh)}] 6 in
which phosphorus–sulfur bond cleavage has occurred but with-
out coupling of either fragment with the alkyne functionality
(eqn. (4)).
[(OC)(η5-C5H5)W(µ-SPh){µ-C(CO2Me)CHC(OMe)O}Co(CO){PPh2-
(SPh)}] 6
W(1)–Co(1)
W(1)–C(4Ј)
Co(1)–S(1)
Co(1)–C(4Ј)
O(1Ј)–C(1Ј)
O(2Ј)–C(2Ј)
O(6Ј)–C(5Ј)
C(2Ј)–C(3Ј)
C(4Ј)–C(5Ј)
P(1)–C(41)
S(1)–C(11)
2.598(2)
2.14(1)
2.244(3)
1.97(1)
1.46(1)
1.27(1)
1.34(1)
1.40(2)
1.47(2)
1.82(1)
1.79(1)
W(1)–O(2Ј)
W(1)–S(1)
Co(1)–P(1)
Co(1)–C(3Ј)
O(1Ј)–C(2Ј)
O(5Ј)–C(5Ј)
O(6Ј)–C(6Ј)
C(3Ј)–C(4Ј)
P(1)–C(31)
P(1)–S(2)
2.163(7)
2.443(3)
2.202(3)
2.06(1)
1.34(1)
1.23(1)
1.42(2)
1.43(1)
1.83(1)
2.118(4)
1.79(1)
S(2)–C(21)
W–C(carbonyl)
Co–C(carbonyl)
1.98(2)
1.75(1)
C–O(W-carbonyl)
C–O(Co-carbonyl) 1.15(1)
1.15(2)
Co(1)–W(1)–S(1)
Co(1)–S(1)–C(4Ј)
C(6)–W(1)–C(4Ј)
C(4Ј)–W(1)–O(5)
W(1)–Co(1)–S(1)
W(1)–Co(1)–C(3Ј)
W(1)–Co(1)–C(7)
S(1)–Co(1)–C(3Ј)
S(1)–Co(1)–C(7)
P(1)–Co(1)–C(3)
C(3)–Co(1)–C(4)
C(4Ј)–C(3Ј)–Co(1)
C(3Ј)–C(4Ј)–W(1)
Co(1)–C(4Ј)–W(1)
C(11)–S(1)–Co(1)
52.76(9)
48.0(3)
126.0(4)
75.6(3)
60.07(8)
76.9(3)
109.0(4)
124.7(3)
117.9(4)
108.6(3)
41.4(4)
Co(1)–W(1)–O(2Ј)
Co(1)–W(1)–C(6)
C(6)–W(1)–O(5)
C(4Ј)–W(1)–S(1)
W(1)–Co(1)–P(1)
W(1)–Co(1)–C(4Ј)
S(1)–Co(1)–P(1)
S(1)–Co(1)–C(4Ј)
P(1)–Co(1)–C(3Ј)
P(1)–Co(1)–C(7)
C(4)–Co(1)–C(8)
C(3Ј)–C(4Ј)–Co(1)
C(2)–C(3)–W(1)
C(11)–S(1)–S(1)
Co(1)–S(1)–W(1)
83.1(2)
80.1(3)
85.7(4)
75.7(3)
154.1(1)
53.8(3)
102.7(1)
83.8(4)
102.3(3)
96.0(4)
107.5(5)
72.4(6)
129.4(9)
109.5(4)
67.16(9)
66.2(6)
108.5(8)
78.2(4)
118.9(4)
1
Complex 6 has been characterised by H, 31P, 13C NMR, IR
spectroscopy and by mass spectrometry and microanalysis (see
Table 1 and Experimental section). In addition complex 6 has
been the subject of a single crystal X-ray diffraction study. The
molecular structure of 6 is shown in Fig. 6 and Table 6 lists
selected bond distances and angles. The complex consists of
a bimetallic core with the W–Co single bond [2.598(2) Å]23
bridged by a phenylthiolato ligand and by a vinyl group in
which the α-carbon is σ-bonded to tungsten [W–C(4Ј) 2.14(1)
Å] and in which the β-carbon is π-coordinated to the cobalt
atom [Co–C(4Ј) 1.97(1), Co–C(3Ј) 2.06(1) Å]. In addition the
O(2Ј) atom on the ester β-substituent of the vinyl group is
bound to the tungsten atom [W–O(2Ј) 2.163(7) Å] so as to form
Fig. 6 Molecular structure of [(OC)(η5-C5H5)W{µ-C(CO2Me)CHC-
(OMe)O}(µ-SPh)Co(CO){PPh2(SPh)}] 6. Hydrogen atoms omitted for
clarity.
a five-membered metallacycle [W–C᎐C–C᎐O]. Similar bonding
᎐
᎐
of the µ-CRCHC(OMe)O ligand has been observed in a num-
ber of homo- and hetero-bimetallic complexes [Fe2,24 Mo2,25
Ru2,26 Mn2,27 Co2,28 CoFe,29 CoMo6]. The coordination sphere
at tungsten is completed by a η5-C5H5 group and a carbonyl
group while that around the cobalt centre is completed by an
equatorial carbonyl group and an axially bound thiophosphine
ligand, which coordinates via the phosphorus donor. The spec-
troscopic properties of 6 are consistent with the solid-state
structure being maintained in solution.
It is uncertain why a complex of the type [{(PhS)Ph2P}-
(CO)2Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] 1f could not be
isolated and indeed why four-membered metallacyclic products
like 2–5 (Fig. 1) are not produced in the attempted preparation.
A possible reason may be the prolonged thermolysis conditions
necessary when tungsten is present compared to those when
molybdenum is present. The formation of complex 6 probably
involves the formation of a hydride at some point, which may
then add to the bridging alkyne. The origin of this hydride is
unknown but may come from impurities in the starting material
or from decomposition products. An alternative possibility is
that the hydrogen atom in 6 is scavenged from the solvent.
3. Conclusions
The regiospecific formation of heterobimetallic complexes of
type 2 first observed when complex 1a was thermolysed6 has
now been shown to be only one possible outcome of a compli-
cated reaction sequence influenced by (i) the nature of the RЈ
substituent, (ii) the cyclopentadienyl group and (iii) the identity
of the Group 6 metal centre in [{(RЈS)Ph2P}(OC)2Co{µ-C2-
(CO2Me)2}M(η5-L)(CO)2] (M = Mo, W; L = C5H5, C5Me5;
RЈ = aryl or alkyl) 1. The facile movement of the thermally
generated thiolate or phosphide fragments around the mixed
J. Chem. Soc., Dalton Trans., 1999, 4447–4456
4453

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metal back-bone has been demonstrated by the isolation of
species 2–5 in which either thiolate or phosphide can be
incorporated into four-membered metallacycles, which contain
either of the two different metal centres. In one case a kinetic
product (3c) has been isolated and converted to its thermo-
dynamically more stable isomer (2c).
NMR (CDCl3): 13C (1H composite pulse decoupled), δ 230.3 [d,
2J(PC) 9, Mo–CO], 208.2 [s, Co–CO], 201.7 [s, Co–CO], 175.3
[s, CO2Me], 173.4 [s, CO2Me], 144–127 [m, Ph], 98.4 [d, 2J(PC)
39, SBunC(CO2Me)C(CO2Me)], 91.2 [s, C5H5], 51.5 [s, Me], 51.2
[s, Me], 47.8 [s, SBunC(CO2Me)], 45.0 [s, CH2], 28.9 [s, CH2],
22.1 [s, CH2] and 13.7 [s, Me]. Complex 3c: FAB mass spectrum,
m/z 720 (Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C
(1H composite pulse decoupled), δ 175.8 [s, CO2Me], 173.5 [s,
CO2Me], 145–125 [m, Ph], 93.2 [s SButC(CO2Me)C(CO2Me)],
92.5 [s, C5H5], 51.5 [s, Me], 50.7 [s, Me], 33.4 [s, SButC(CO2Me)]
and 29.0 [s, But]. Complex 2b: FAB mass spectrum, m/z 720
(Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C (1H com-
4. Experimental
(a) General techniques
All reactions were carried out under a nitrogen atmosphere
using standard Schlenk techniques. Solvents were distilled
under nitrogen from appropriate drying agents and degassed
prior to use. Preparative thin-layer chromatography (TLC) was
carried out on commercial Merck plates with a 0.25 mm layer
of silica, or on 1 mm silica plates prepared at the University
Chemical Laboratory, Cambridge. Column chromatography
was performed on Kieselgel 60 (70–230 or 230–400 mesh).
Products are given in order of decreasing Rf values.
The instrumentation used to obtain spectroscopic data has
been described previously.30 Unless otherwise stated all reagents
were obtained from commercial suppliers while Ph2P(SRЈ)
(RЈ = But, Bun, Ph),9,31 [(OC)3Co{µ-C2(CO2Me)2}Mo(η5-C5-
Me5)(CO)2], [(OC)3Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2], and
[(OC)3Co{µ-C2(CO2Me)2}Mo(η5-C5H5)(CO)2] were prepared
by literature methods.11b,32
2
posite pulse decoupled), δ 242.1 [d, J(PC) 12, Mo–CO], 208.2
[s, Co–CO], 207.8 [s, Co–CO], 177.7 [s, CO2Me], 172.3 [s,
2
CO2Me], 143–127 [m, Ph], 109.6 [d, J(PC) 27, PPh2C(CO2-
Me)C(CO2Me)], 90.8 [s, C5H5], 51.7 [s, Me], 51.1 [s, Me], 43.5 [s,
CH2], 29.2 [s, CH2], 22.3 [s, CH2] and 13.6 [s, Me]. Complex 2c:
(Found: C, 49.63; H, 4.06. C30H30O7PSCoMo requires C, 50.00;
H, 4.17%). FAB mass spectrum, m/z 720 (Mϩ) and Mϩ Ϫ nCO
(n = 1–3). NMR (CDCl3): 13C (1H composite pulse decoupled),
δ 240.5 [d, 2J(PC) 40, Mo–CO], 210.0 [s, Co–CO], 206.0 [s, Co–
CO], 179.5 [s, CO2Me], 170.5 [s, CO2Me], 135–125 [m, Ph],
107.4 [d, 2J(PC) 40, PPh2C(CO2Me)C(CO2Me)], 91.3 [s, C5H5],
52.9 [s, PPh2C(CO2Me)C(CO2Me)], 51.7 [s, Me], 51.5 [s, Me]
and 34.0 [s, But].
(d) Reaction of [(OC)3Co{ꢀ-C2(CO2Me)2}Mo(ꢁ5-C5Me5)(CO)2]
with Ph2P(SPh)
(b) The reaction of [(OC)3Co{ꢀ-C2(CO2Me)2}Mo(ꢁ5-C5H5)-
(CO)2] with Ph2P(SRЈ)
To a solution of [(OC)3Co{µ-C2(CO2Me)2}Mo(η5-C5Me5)-
(CO)2] (1.00 g, 1.75 mmol) in toluene (50 cm3) was added excess
Ph2P(SPh) (0.70 g, 2.38 mmol) in toluene (50 cm3). The solution
was stirred at 298 K for 24 h and after removal of the solvent
under reduced pressure the residue was dissolved in the min-
imum quantity of CH2Cl2 and absorbed onto a minimum
amount of silica, added to the top of chromatography column
and eluted with hexane–ethyl acetate (2:1). This gave, in addi-
tion to a small amount of unreacted starting material, the
orange crystalline complex [{(PhS)Ph2P}(OC)2Co{µ-C2(CO2-
Me)2}Mo(η5-C5Me5)(CO)2] 1d (0.983 g, 67%). Complex 1d:
FAB mass spectrum, m/z 838 (Mϩ) and Mϩ Ϫ nCO (n = 1–3).
NMR (CDCl3): 13C (1H composite pulse decoupled), δ 226.5 [s,
W–CO], 208.4 [s, Co–CO], 172.4 [s, C2(CO2Me)2], 135–127 [m,
Ph], 103.7 [s, C5Me5], 72.2 [s, C2(CO2Me)2], 51.4 [s, C2(CO2-
Me)2] and 10.7 [s, C5Me5].
To a solution of [(OC)3Co{µ-C2(CO2Me)2}Mo(η5-C5H5)(CO)2]
(1.00 g, 1.99 mmol) in toluene (70 cm3) was added solutions of
the thiophosphines L {L = Ph2P(SBun) (1.00 g, 3.6 mmol) or
Ph2P(SBut) (1.00 g, 3.6 mmol)} in toluene (20 cm3). The solu-
tions were stirred at 298 K for 24 h and after removal of the
solvents under reduced pressure the mixtures were absorbed
onto a minimum amount of silica, added to the top of chrom-
atography columns and eluted with hexane–dichloromethane
(10:1). This gave, in addition to a small amount of unreacted
starting material, orange crystalline [(OC)2{(RЈS)Ph2P}Co-
{µ-C(CO2Me)2}Mo(η5-C5H5)(CO)2] {RЈ = Bun 1b (1.176 g,
79%); But 1c (1.101 g, 74%)}. Complex 1b: FAB mass spectrum,
m/z 748 (Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C (1H
composite pulse decoupled), δ 223.5 [s, Mo–CO], 205.6 [s, Co–
CO], 172.6 [s, C2(CO2Me)2], 134–128 [m, Ph], 90.4 [s, C5H5],
70.8 [s, C2(CO2Me)2], 51.6 [s, C2(CO2Me)2] and 32.5 [s, But].
Complex 1c: FAB mass spectrum, m/z 748 (Mϩ) and
Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C (1H composite pulse
decoupled), δ 222.6 [s, Mo–CO], 204.9 [s, Co–CO], 172.5 [s,
C2(CO2Me)2], 134–128 [m, Ph], 90.6 [s, C5H5], 70.8 [s,
C2(CO2Me)2], 51.7 [s, C2(CO2Me)2], 32.3 [s, CH2], 31.5 [s, CH2],
21.7 [s, CH2] and 13.4 [s, Me].
(e) Thermolysis of [{(PhS)Ph2P}(OC)2Co{ꢀ-C2(CO2Me)2}-
Mo(ꢁ5-C5Me5)(CO)2] 1d
A solution of [{(PhS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-
C5Me5)(CO)2] 1d (0.500 g, 0.60 mmol) in toluene (50 cm3) was
thermolysed at 383 K for 2 h. After removal of the solvent
under reduced pressure, the mixture was separated using pre-
parative TLC with hexane–ethyl acetate (2:1) as eluent. This
gave, in addition to a small amount of unreacted starting
material, the orange crystalline complexes [(OC)2Co{µ-SPhC-
(CO2Me)C(CO2Me)}(µ-PPh2)Mo(η5-C5Me5)(CO)] 3d (0.111 g,
23%), [(OC)2Co{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SPh)Mo(η5-
C5Me5)(CO)] 4d (0.126 g, 26%) and [(OC)(η5-C5Me5)Mo-
{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SPh)Co(CO)2] 2d (0.068 g,
14%)}. Complex 3d: FAB mass spectrum, m/z 810 (Mϩ) and
Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C (1H composite pulse
decoupled), δ 177.6 [s, CO2Me], 175.3 [s, CO2Me], 139–128 [m,
Ph], 106.2 [s, SPhC(CO2Me)C(CO2Me)], 102.5 [s, C5Me5], 53.7
[s, CO2Me], 51.1 [s, CO2Me] and 10.7 [s, C5Me5]. Complex 4d:
FAB mass spectrum, m/z 810 (Mϩ) and Mϩ Ϫ nCO (n = 1–3).
NMR (CDCl3): 13C (1H composite pulse decoupled), δ 176.0
[s, CO2Me], 171.1 [s, CO2Me], 137–128 [m, Ph], 106.2 [s, PPh2-
C(CO2Me)C(CO2Me)], 102.6 [s, C5Me5], 50.9 [s, CO2Me], 50.7
[s, CO2Me], 31.1 [d, 1J(PC) 42, PPh2C(CO2Me)C(CO2Me)] and
(c) Thermolysis of [{(RЈS)Ph2P}(OC)2Co{ꢀ-C2(CO2Me)2}-
Mo(ꢁ5-C5H5)(CO)2] (RЈ ؍ Bun 1b, But 1c)
Solutions of [{(RЈS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}Mo(η5-
C5H5)(CO)2] (RЈ = Bun 1b, 0.300 g, 0.40 mmol; But 1c, 0.300 g,
0.40 mmol) in toluene (50 cm3) were thermolysed at 363 K for
2–3 h. After removal of the solvent under reduced pressure, the
mixtures were separated using preparative TLC with hexane–
ethyl acetate (2:1) as eluent. This gave, in addition to a small
amount of unreacted starting material, yellow crystalline
[(OC)2Co{µ-SRЈC(CO2Me)C(CO2Me)}(µ-PPh2)Mo(η5-C5H5)-
(CO)] {RЈ = Bun 3b (0.101 g, 35%), But 3c (0.121 g, 42%)}
and red-green crystalline [(OC)(η5-C5H5)Mo{µ-PPh2C(CO2-
Me)C(CO2Me)}(µ-SRЈ)Co(CO)2] {RЈ = Bun 2b (0.124 g, 43%),
But 2c (0.118 g, 41%)} complexes. Complex 3b (Found: C,
50.11; H, 4.10. C30H30O7PSCoMo requires C, 50.00; H, 4.17%):
FAB mass spectrum, m/z 720 (Mϩ) and Mϩ Ϫ nCO (n = 1–3).
4454
J. Chem. Soc., Dalton Trans., 1999, 4447–4456

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10.7 [s, C5Me5]. Complex 2d: FAB mass spectrum, m/z 810 (Mϩ)
and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C (1H composite
pulse decoupled), δ 242.0 [s, Mo–CO], 206.9 [s, Co–CO], 176.1
[s, CO2Me], 171.1 [s, CO2Me], 138–126 [m, Ph], 51.1 [s,
CO2Me], 50.8 [s, CO2Me], 30.0 [d, PPh2C(CO2Me)C(CO2Me)]
and 10.5 [s, C5Me5].
FAB mass spectrum, m/z 910 (Mϩ) and Mϩ Ϫ nCO (n = 1–3).
NMR (CDCl3): 13C (1H composite pulse decoupled), δ 243.4
[d,2J(PC)11,W–CO],212.1[s, Co–CO],188.2[d,2J(PC)10,CO2-
Me], 180.8 [s, CO2Me], 141–128 [m, Ph], 120.4 [s, C(CO2Me)],
91.6 [s, C5H5], 53.7 [s, CO2Me] and 50.9 [s, CO2Me].
(j) Thermolysis of [{(BunS)Ph2P}(OC)2Co{ꢀ-C2(CO2Me)2}-
W(ꢁ5-C5H5)(CO)2] 1e
(f) Thermolysis of [(OC)2Co{ꢀ-SButC(CO2Me)C(CO2Me)}-
(ꢀ-PPh2)Mo(ꢁ5-C5H5)(CO)] 3c
A solution of [{(BunS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}W(η5-
C5H5)(CO)2] 1e (0.300 g, 0.36 mmol) in toluene (50 cm3) was
thermolysed at 383 K for 8 h. After removal of the solvent
under reduced pressure, the mixture was separated using
preparative TLC with hexane–ethyl acetate (2:1) as eluent.
This gave, in addition to a small amount of unreacted starting
material and uncharacterised products, the brown crystalline
complexes [(CO)(η5-C5H5)W{µ-SBunC(CO2Me)C(CO2Me)}-
(µ-PPh2)Co(CO)2] 5e (0.061 g, 21%) and [(CO)2Co{µ-SBun-
C(CO2Me)C(CO2Me)}(µ-PPh2)W(η5-C5H5)(CO)] 3e (0.122 g,
42%). Complex 5e (Found: C, 44.42; H, 3.63. C30H30O7PS2-
CoW requires C, 44.55; H, 3.71%): FAB mass spectrum, m/z
808 (Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C (1H
composite pulse decoupled), δ 231.4 [d, 2J(PC) 9, W–CO], 210.2
[s, Co–CO], 207.2 [s, Co–CO], 177.9 [s, CO2Me], 174.4 [s,
CO2Me], 143–128 [m, Ph], 95.9 [d, 2J(PC) 24, SBunC(CO2-
Me)C(CO2Me)], 88.2 [s, C5H5], 51.7 [s, CO2Me], 51.0 [s,
CO2Me], 45.5 [s, CH2], 35.2 [d, 2J(PC) 10, SBunC(CO2Me)-
C(CO2Me)] and 29–13 [m, Bun]. Complex 3e (Found: C, 44.40;
H, 3.65. C30H30O7PSCoW requires C, 44.55; H, 3.71%): FAB
mass spectrum, m/z 808 (Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR
(CDCl3): 13C (1H composite pulse decoupled), δ 232.5 [s, W–
CO], 209.2 [s, Co–CO], 207.2 [s, Co–CO], 177.1 [s, CO2Me],
174.1 [s, CO2Me], 134–128 [m, Ph], 90.5 [s, C5H5], 51.6
[s, CO2Me], 51.3 [s, CO2Me], 48.9 [s, CH2], 28.8 [s, CH2], 22.2
[s, CH2] and 13.8 [s, Me].
A
solution of [(OC)2Co{µ-SButC(CO2Me)C(CO2Me)}-
(µ-PPh2)Mo(η5-C5H5)(CO)] 3c (0.100 g, 0.14 mmol) in toluene
(50 cm3) was thermolysed at 383 K for 4 h. After removal of the
solvent under reduced pressure, the mixture was separated
using preparative TLC with hexane–ethyl acetate (2:1) as
eluent. This gave, in addition to a small amount of unreacted
starting material, the red-green crystalline complex [(OC)-
(η5-C5H5)Mo{µ-PPh2C(CO2Me)C(CO2Me)}(µ-SBut)Co(CO)2]
2c (0.830 g, 83%).
(g) Reaction of [(OC)2Co{ꢀ-SButC(CO2Me)C(CO2Me)}-
(ꢀ-PPh2)Mo(ꢁ5-C5H5)(CO)] 3c with P(OMe)3
To
a
solution of [(OC)2Co{µ-SButC(CO2Me)C(CO2Me)}-
(µ-PPh2)Mo(η5-C5H5)(CO)] 3c (0.100 g, 0.14 mmol) in toluene
(50 cm3) was added P(OMe)3 (0.10 cm3, 0.85 mmol). The solu-
tion was stirred at 298 K for 24 h and after removal of the
solvent under reduced pressure, the mixture was separated
using preparative TLC with hexane–ethyl acetate (2:1) as
eluent. This gave the orange crystalline complex [{(MeO)3P}-
(OC)Co{µ-SButC(CO2Me)C(CO2Me)}(µ-PPh2)Mo(η5-C5H5)-
(CO)] 3cЈ (0.952 g, 84%). Complex 3cЈ: FAB mass spectrum,
m/z 816 (Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3): 13C
(1H composite pulse decoupled), δ 235.1 [s, Mo–CO], 206.3
[s, Co–CO], 177.2 [s, CO2Me], 174.1 [s, CO2Me], 145–125
[m, Ph], 96.3 [s, SButC(CO2Me)C(CO2Me)], 93.0 [s, C5H5],
51.3 [s, Me], 50.6 [s, Me], 34.0 [s, SButC(CO2Me)] and 29.8
[s, But].
(k) Crystal structure determinations of complexes 1d, 2b, 3cЈ,
5e and 6
(h) The reaction of [(OC)3Co{ꢀ-C2(CO2Me)2}W(ꢁ5-C5H5)-
(CO)2] with Ph2P(SBun)
X-Ray intensity data were collected on a Phillips PW1100
four-circle diffractometer for 2b and 5e, on a Stöe four-circle
diffractometer for 3cЈ and 6 and for 1d on a Rigaku AFC5R
four-circle diffractometer. Details of the data collection,
refinement and crystal data are given in Table 7. The data were
corrected for Lorentz polarisation factors. Absorption correc-
tions based on ψ-scans33 were applied to the data of 1d, 3cЈ and
6. After refinement with isotropic displacement parameters for
all atoms, empirical corrections34 were applied to the data of 2b
and 5e.
For 2b and 5e, the metal positions were deduced from
Patterson syntheses and the remaining non-hydrogen atoms
were located from subsequent difference-Fourier syntheses.
Refinement was based of F.35
For 1d, 3cЈ and 6, the positions of the metal atoms and most
of the non-hydrogen atoms were located from direct methods,36
and the remaining non-hydrogen atoms were revealed from
subsequent difference-Fourier syntheses. Refinement was based
on F2.
To a solution of [(OC)3Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2]
(0.500 g, 0.85 mmol) in toluene (50 cm3) excess Ph2P(SBun) (1.0
cm3, 5.75 mmol) was added. This solution was stirred at 298 K
for 24 h and after removal of the solvents under reduced pres-
sure the mixture was absorbed onto a minimum amount of
silica, added to the top of chromatography column and eluted
with hexane–ethyl acetate (2:1). This gave, in addition to a
small amount of unreacted starting material, orange crystalline
[{(BunS)Ph2P}(OC)2Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2] 1e
(0.473 g, 65%). Complex 1e (Found: C, 44.60; H, 3.64.
C31H30O8PSCoW requires C, 43.46; H, 3.50%): FAB mass spec-
trum, m/z 856 (Mϩ) and Mϩ Ϫ nCO (n = 1–3). NMR (CDCl3):
13C (1H composite pulse decoupled), δ 235.2 [s, W–CO], 210.2
[s, Co–CO], 173.5 [s, C2(CO2Me)2], 133–128 [m, Ph], 88.4 [s,
C5H5], 50.9 [s, C2(CO2Me)2], 32.2 [s, CH2], 31.6 [s, CH2], 21.8 [s,
CH2] and 13.5 [s, CH3].
In 2b and 5e the phenyl and cyclopentadienyl rings were
constrained to refine with idealised geometries. Hydrogen
atoms for these structures were placed in calculated positions
with displacement parameters of 0.1 Å2, except those of the
cyclopentadienyl ring in 2b.
For 1d, 3cЈ and 6, hydrogen atoms were placed in calculated
positions with displacement parameters equal to 1.5 Ueq of the
parent carbon atoms (1.2 Ueq of parent atoms for phenyl hydro-
gen atoms in 1d). All non-hydrogen atoms were assigned aniso-
tropic displacement parameters except the phenyl carbon atoms
in 2b. Some disorder of one OMe substituent of the P(OMe)3
ligand was noted in 3cЈ and the methyl carbon atom was
assigned two sites of ca. 50% occupancy.
(i) The reaction of [(OC)3Co{ꢀ-C2(CO2Me)2}W(ꢁ5-C5H5)(CO)2]
with Ph2P(SPh)
To a solution of [(OC)3Co{µ-C2(CO2Me)2}W(η5-C5H5)(CO)2]
(0.500 g, 0.85 mmol) in toluene (50 cm3) was added Ph2P(SPh)
(0.300 g, 1.02 mmol). After thermolysis at 373 K for 7 h
and removal of the solvent under reduced pressure, the mix-
ture was separated using preparative TLC with hexane–ethyl
acetate (2:1) as eluent. This gave, in addition to a small amount
of uncharacterised product, the orange crystalline com-
plex [(OC)(η5-C H )W{µ-C(CO Me)᎐CHC(OMe)O}(µ-SPh)-
᎐
5
5
2
Co(CO){PPh2(SPh)}] 6 (0.286 g, 37%). Complex 6 (Found: C,
48.65; H, 3.49. C37H32O6PS2CoW requires C, 48.81; H, 3.54%).
J. Chem. Soc., Dalton Trans., 1999, 4447–4456
4455

View Article Online
Table 7 Crystallographic and data processing parameters for complexes 1d, 2b, 3cЈ, 5e and 6
Complex
1d
2b
3cЈ
5e
6
Empirical formula
Formula weight
C38H36CoMoO8PS
838.57
C30H30CoMoO7PS
720.38
C32H39CoMoO9P2S
816.50
C30H30CoWO7PS
808.35
C37H32CoWO6PS2
910.50
Crystal system
Space group
Monoclinic
P21/n
Monoclinic
P21/n
Monoclinic
P21/n
Triclinic
P1 (no. 2)
Triclinic
P1 (no. 2)
¯
¯
a/Å
b/Å
c/Å
α/Њ
9.517(2)
9.699(2)
40.567(8)
—
91.39(3)
—
3744(1)
4
1.488
0.927
12.823(3)
15.293(4)
16.643(4)
—
103.19(3)
—
3178(1)
4
1.510
11.148(2)
18.141(4)
17.411(3)
—
94.33(3)
—
3511(1)
4
1.545
1.031
8.997(2)
12.386(3)
13.955(3)
85.13(3)
77.88(3)
88.51(3)
1515(1)
2
9.555(2)
10.419(2)
19.358(4)
76.22(3)
76.57(3)
73.19(3)
1763.8(6)
2
β/Њ
γ/Њ
U/Å3
Z
Dc/g cmϪ1
1.772
4.510
760
1.714
3.937
900
µ(Mo-Kα)/mmϪ1
F(000)
0.818
1464
1712
1672
Reflections collected
Independent reflections
Final R indices I > 2σ(I)
10498
6024
4725
5562
4918
4896 [Rint = 0.1335]
R1 = 0.0481,
wR2 = 0.0814
R1 = 0.1603,
wR2 = 0.5203
2915 [I > 3σ(I)]
R = 0.0521,
RЈ = 0.0552
—
4557 [Rint = 0.0263]
R1 = 0.0410,
wR2 = 0.1150
R1 = 0.0623,
wR2 = 0.1455
4005 [I > 3σ(I)]
R = 0.0584,
RЈ = 0.0617
—
4618 [Rint = 0.0492]
R1 = 0.0509,
wR2 = 0.1078
R1 = 0.0824,
wR2 = 0.1224
All data
Trans., 1991, 3103; A. J. M. Caffyn, M. J. Mays, G. A. Solan,
D. Braga, P. Sabatino, A. Tiripicchio and M. Tiripicchio-Camellini,
Organometallics, 1993, 12, 1876.
CCDC reference number 186/1692.
See http:/www.rsc.org/suppdata/dt/1999/4447/ for crystallo-
graphic files in .cif format.
19 See for example, L. S. Chia, W. R. Cullen, M. Franklin and A. R.
Manning, J. Organomet. Chem., 1983, 243, C21; J. J. Bonnet and
R. Mathieu, Inorg. Chem., 1978, 17, 1973; A. J. M. Caffyn,
A. Martín, M. J. Mays, P. R. Raithby and G. A. Solan, J. Chem.
Soc., Dalton Trans., 1994, 609.
20 Co–S bond lengths in related organo-bridged homo- or hetero-
bimetallic complexes range from 2.12 to 2.29 Å. See refs. 6–8, 21.
21 W. D. Jones and R. M. Chin, Organometallics, 1992, 11, 2698;
A. J. Edwards, S. R. Mack, M. J. Mays, C.-Y. Mo, P. R. Raithby and
M.-A. Rennie, J. Organomet. Chem., 1996, 519, 243.
22 M. Nishio, H. Matsuzaka, Y. Mizobe, T. Tanase and M. Hidai,
Organometallics, 1994, 13, 4214; U. Koelle, C. Rietmann, J. Tjoe,
T. Wagner and U. Englert, Organometallics, 1995, 14, 703; R.
Rumin, K. Guernou, F. Y. Petillon and K. W. Muir, J. Chem. Soc.,
Dalton Trans., 1997, 1381.
23 Single metal–metal bond distances for organo-bridged Co–W
complexes range from 2.55 to 2.76 Å, see for example (a) T. M.
Wido, G. H. Young, A. Wojcicki, M. Calligaris and G. Nardin,
Organometallics, 1988, 7, 452; (b) J. Antonio Abad, L. W. Bateman,
J. C. Jeffery. K. A. Mead, H. Razay, F. G. A. Stone and
P. Woodward, J. Chem. Soc., Dalton Trans., 1983, 2075; (c) J. L.
Davidson, L. Manojlovic-Muir, K. W. Muir and A. N. Keith,
J. Chem. Soc., Chem. Commun., 1980, 749; (d) J. C. Jeffery, I.
Moore, H. Razay and F. G. A. Stone, J. Chem. Soc., Dalton Trans.,
1984, 1581.
Acknowledgements
This work was supported by the EPSRC (to G. E. P.).
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