Incorporation of thiophene rings into tri- and tetraruthenium clusters via cyclometalation and C-P bond cleavage of the ligand diphenyl-2-thienylphosphine

Article abstract of DOI:10.1021/om9503205

Diphenyl-2-thienylphosphine, Ph₂PC₄H₃S (1), reacts with [Ru₃(CO)₁₂] in refluxing toluene to give the compound [Ru₃(μ₂-H)(μ₃-Ph₂PC ₄H₂S)(CO)₉] (2) (59%), cyclometalated at the thiophene ring, with smaller amounts of the cluster [Ru₃(μ₂-H)(μ₃-Ph₂PC ₄H₂S)(CO)₈(Ph₂-PC₄H ₃S)] (3) (10%), which is a substituted derivative of 2 and may also be formed by substitution at 2 with ligand 1. The single-crystal X-ray structure of cluster 2 shows that it contains the μ₃-ligand Ph₂PC₄H₂S bound through phosphorus to one Ru atom, through a σ-Ru-C bond to another and by an η² interaction to the third. There is a dynamic interchange between the σ and η² interactions of the thienyl group leading to NMR coalescence and a time-averaged plane of symmetry. The corresponding process would be nondegenerate in the substituted compound 3 (X-ray structure reported) and is quenched. Thermal treatment of cluster 2 with [Ru₃(CO)₁₂] gave two tetranuclear clusters, [Ru₄(μ₄-PPh)(μ₄-C₄H ₂S)(CO)₁₁] (5) by elimination of benzene and the known cluster [Ru₄(μ₄-PPh)-(μ₄-C₆H ₄)(CO)₁₁] (6) by elimination of thiophene. Although compounds 5 and 6 are stoichiometrically equivalent, their single-crystal X-ray structures show that they adopt different geometries. The structure of 6 was shown to be the same as that reported previously for the compound derived from PPh₃. Each has an approximate square of metal atoms capped on one side by μ₄-PPh and on the other by μ₄-thiophyne (C₄H₂S) or μ₄-benzyne (C₆H₄), respectively. The C₆H₄ ligand is coordinated as a 6-electron donor, tilted with respect to the Ru₄ plane, with the coordinated C-C bond parallel to an Ru-Ru edge, whereas C₄H₂S is coordinated as a 4-electron donor, perpendicularly and diagonally across the Ru₄ plane in a manner related to known alkyne clusters of the type [Ru₄(μ₄-PPh)(μ₄-alkyne)(CO) ₁₁].

Full text of DOI:10.1021/om9503205

786
Organometallics 1996, 15, 786-793
In cor p or a tion of Th iop h en e Rin gs in to Tr i- a n d
Tetr a r u th en iu m Clu ster s via Cyclom eta la tion a n d C-P
Bon d Clea va ge of th e Liga n d
Dip h en yl-2-th ien ylp h osp h in e
Antony J . Deeming* and Shiraj N. J ayasuriya
Department of Chemistry, University College London, 20 Gordon Street,
London WC1H 0AJ , Great Britain
Alejandro J . Arce and Ysaura De Sanctis
Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas (IVIC),
Apartado 21827, Caracas 1020-A, Venezuela
Received May 3, 1995X
Diphenyl-2-thienylphosphine, Ph2PC4H3S (1), reacts with [Ru3(CO)12] in refluxing toluene
to give the compound [Ru3(µ2-H)(µ3-Ph2PC4H2S)(CO)9] (2) (59%), cyclometalated at the
thiophene ring, with smaller amounts of the cluster [Ru3(µ2-H)(µ3-Ph2PC4H2S)(CO)8(Ph2-
PC4H3S)] (3) (10%), which is a substituted derivative of 2 and may also be formed by
substitution at 2 with ligand 1. The single-crystal X-ray structure of cluster 2 shows that
it contains the µ3-ligand Ph2PC4H2S bound through phosphorus to one Ru atom, through a
σ-Ru-C bond to another and by an η2 interaction to the third. There is a dynamic
interchange between the σ and η2 interactions of the thienyl group leading to NMR
coalescence and a time-averaged plane of symmetry. The corresponding process would be
nondegenerate in the substituted compound 3 (X-ray structure reported) and is quenched.
Thermal treatment of cluster 2 with [Ru3(CO)12] gave two tetranuclear clusters, [Ru4(µ4-
PPh)(µ4-C4H2S)(CO)11] (5) by elimination of benzene and the known cluster [Ru4(µ4-PPh)-
(µ4-C6H4)(CO)11] (6) by elimination of thiophene. Although compounds 5 and 6 are
stoichiometrically equivalent, their single-crystal X-ray structures show that they adopt
different geometries. The structure of 6 was shown to be the same as that reported previously
for the compound derived from PPh3. Each has an approximate square of metal atoms capped
on one side by µ4-PPh and on the other by µ4-thiophyne (C4H2S) or µ4-benzyne (C6H4),
respectively. The C6H4 ligand is coordinated as a 6-electron donor, tilted with respect to
the Ru4 plane, with the coordinated C-C bond parallel to an Ru-Ru edge, whereas C4H2S
is coordinated as a 4-electron donor, perpendicularly and diagonally across the Ru4 plane in
a manner related to known alkyne clusters of the type [Ru4(µ4-PPh)(µ4-alkyne)(CO)11].
In tr od u ction
C-S cleavage to give metallasulfacyclohexadiene
systems.1-3,5-9 It is the latter, in particular, that relates
to the HDS process and the question of whether ring
opening precedes or follows hydrogenation in the cata-
lytic system has been addressed.1 In a few cases
thiophene has been incorporated into bidentate, poly-
dentate, or macrocyclic ligands but this area has not
been widely developed.10-12
The organometallic chemistry of thiophene has been
studied from the point of view the the hydrodesulfur-
ization process required to remove thiophenic sulfur
from oil.1 Thiophene and its benzo derivatives are not
particularly good ligands with transition metals, even
with soft metals that normally bond strongly to sulfur.
Most studies of their coordination chemistry have
centered on the different observed types of coordination
to a single metal atom through sulfur alone or by
π-complexation through carbon and sulfur atoms (η2, η4,
or η5). Sometimes isomers with different types of
thiophene attachment are found in equilibrium.2-4
Oxidative addition reactions of thiophene are also
important. These can lead to 2-thienyl hydrido com-
plexes by C-H bond cleavage or to ring opening with
We set out to extend the organometallic chemistry of
thiophene by introducing the thiophene ring into clus-
(5) Sanchez-Delgado, R. A.; Herrera, V.; Rincon, L.; Andriollo, A.;
Martin, G. Organometallics 1994, 13, 553. Bianchini, C.; Meli, A.;
Peruzzini, M.; Vizza, F.; Moneti, S.; Herrera, V.; Sanchez-Delgado, R.
A. J . Am. Chem. Soc. 1994, 116, 4370. Selnau, H. E.; Merola, J . S.
Organometallics 1993, 12, 1583.
(6) J ones, W. D.; Chin, R. M. J . Organomet. Chem. 1994, 472, 311.
(7) Buys, I. E.; Field, L. D.; Hambley, T. W.; McQueen, A. E. D. J .
Chem. Soc., Chem. Commun. 1994, 557.
(8) Harris, S. Organometallics 1994, 13, 2628.
(9) J ones, W. D.; Chin, R. M.; Crane, T. W.; Baruch, D. M.
Organometallics 1994, 13, 4448.
(10) Neve, F.; Ghedini, M.; Crispini, A. J . Organomet. Chem. 1994,
466, 259.
(11) Latos-Grazynski, L.; Lisowski, J .; Olmstead, M. M.; Balch, A.
L. Inorg. Chem. 1989, 28, 1183.
(12) Latos-Grazynski, L.; Olmstead, M. M.; Balch, A. L. Inorg. Chem.
1989, 28, 4065.
X Abstract published in Advance ACS Abstracts, October 1, 1995.
(1) Angelici, R. J . Encyclopedia of Inorganic Chemistry; King, R. B.,
Ed.; Wiley: New York, 1994; Vol. 3, pp 1433-1443.
(2) Rauschfuss, T. B. J . Prog. Inorg. Chem. 1991, 39, 259.
(3) Angelici, R. J . Coord. Chem. Rev. 1990, 105, 61.
(4) Robertson, M. J .; Day, C. L.; J acobson, R. A.; Angelici, R. J .
Organometallics 1994, 13, 179.
0276-7333/96/2315-0786$12.00/0 © 1996 American Chemical Society

Tri- and Tetraruthenium Clusters
Organometallics, Vol. 15, No. 2, 1996 787
Sch em e 1
ters by the use of the known ligand diphenyl-2-thie-
nylphosphine (1),13-15 which might act as a bridge
through the two heteroatoms or through phosphorus
and the π-electrons of the heterocyclic component.
Attempts to achieve this previously with 1 have not been
reported. The only known complexes of 1 have the
ligand as a simple tertiary phosphine coordinated
through phosphorus such as in [MCl2(Ph2PC4H3S)2] (M
) Pd, Pt)16-19 and in [Rh(cod)(Ph2PC4H3S)2]BF4,20 both
of which are a square-planar four-coordinate complexes.
There is no evidence for coordination of thienyl groups
in such compounds. However, we have recently syn-
thesized a derivative of [Re2(CO)10] and ligand 1,
[Re2(CO)8(µ-Ph2PC4H3S)], and shown this to have a
bridging ligand coordinated through both the sulfur and
phosphorus atoms.21 Recent work on tris(2-thienyl)-
phosphine with [Ru3(CO)12] has led to trinuclear and
mononuclear compounds in which the ligand behaves
as a simple tertiary phosphine.22 No sulfur coordination
or cyclometalation was observed.
In this paper we describe results on reactions of 1
with [Ru3(CO)12] which do not lead to bridging-1 sys-
tems related to [Re2(CO)8(µ-Ph2PC4H3S)], as might be
expected, but instead to the cyclometalated ligand µ3-
Ph2PC4H2S, and reactions involving the interconversion
of this with a cluster containing the unmetalated
monodentate ligand 1. In addition to C-H cleavage we
have observed P-C cleavage to give an unprecedented
µ4-thiophyne ligand (C4H2S). Previously we have re-
ported the thiophyne ligand in a µ3-coordination mode
and the parent thienyl ligand (C4H3S) in a µ2-coordina-
tion mode in both osmium and ruthenium clusters.23-27
Instead the major product was the cyclometalated
thienylphosphine cluster [Ru3(µ-H)(µ3-Ph2PC4H2S)(CO)9]
(2) (59%) in addition to a small amount of a substituted
derivative of compound 2, [Ru3(µ-H)(µ3-Ph2PC4H2S)-
(CO)8(Ph2PC4H3S)] (3) (10%), and some unreacted [Ru3-
(CO)12]. Unreacted [Ru3(CO)12] is expected because two
ligands 1 are incorporated into the cluster 3 leaving a
deficiency of ligand 1 for complete conversion of the
starting metal carbonyl. We have established that the
cluster [Ru3(CO)11(Ph2PC4H3S)] (4), formed by treat-
ment of 2 with CO in a sealed tube at 80 °C, is reactive
toward decarbonylation to give cluster 2. Therefore it
is not surprising that 4 was not observed spectroscopi-
cally during the thermal reaction of 1 with [Ru3(CO)12]
in refluxing toluene.
Scheme 1 shows the formation of clusters 2-4 from
ligand 1. We presume that cluster 4 is formed initially
but readily loses CO to form either or both of the
unobserved intermediates A and B. Loss of CO from
[Re2(CO)9(Ph2PC4H3S)] leads to [Re2(CO)8(µ-Ph2PC4H5S)],
containing the µ-ligand bonded through P and S atoms
as in the supposed intermediate B,21 but intermediate
B is less likely than A to be directly on the route from
4 to 2. The ready formation of 2 from 4 means that
intermediate A also readily loses CO to give 4. Treat-
ment of 2 with CO gives 4 and not A (or B) so A must
both readily lose and pick up CO and therefore be
inaccessible by the thermal methods that we have used.
There is evidence that the 2-thienyl substituent on 1
cyclometalates more rapidly than the phenyl substituent
and also that the P-thienyl bond is not so readily
cleaved as P-Ph bonds. Thiophene is known to be more
reactive toward electrophiles than benzene, and this
may relate to its enhanced susceptibilty toward meta-
lation.28 Scheme 2 shows the corresponding behavior
established for PR2Ph ligands, including PPh3, where
ready formation of µ3-C6H4 occurs following cyclometa-
lation both with ruthenium and osmium.29-33 With
ruthenium but not osmium there are subsequent reac-
tions leading to Ru4- and Ru5-C6H4 species.32,33 The
Resu lts a n d Discu ssion
Rea ction of [Ru 3(CO)12] w ith Dip h en yl-2-th ie-
n ylp h osp h in e (1). The ligand diphenyl-2-thienylphos-
phine has been synthesized previously by the reaction
of 2-thienylmagnesium iodide15 or 2-thienyllithium14
with Ph2PCl or by reaction of 2-iodothiophene with Me3-
SnPPh2, a reaction which is catalyzed by [PdCl2-
(MeCN)2].13 We have used a modified method based on
the 2-thienyllithium route (see Experimental Section).
Reaction of 1 with an equimolar amount of [Ru3(CO)12]
in refluxing toluene for 30 min showed no evidence,
either spectroscopic or after subsequent workup, for the
formation of simple substitution derivatives such as
[Ru3(CO)11(1)], [Ru3(CO)10(µ-1)], [Ru3(CO)10(1)2], etc.
(13) Tunney, S. E.; Stille, J . K. J . Org. Chem. 1987, 52, 748.
(14) Allen, D. W.; Charlton, J . R.; Hutley, B. G. Phosphorus 1976,
6, 191.
(15) Horner, L.; Roeder, J . Phosphorus 1976, 6, 147.
(16) Allen, D. W.; Taylor, B. F. J . Chem. Soc., Dalton Trans. 1982,
51.
(17) Varshney, A.; Gray, G. M. Inorg. Chim. Acta 1988, 148, 215.
(18) Sanger, A. R. Can. J . Chem. 1984, 62, 2168.
(19) Allen, D. W.; Ashford, D. F. J . Inorg. Nucl. Chem. 1976, 38,
1953.
(20) Dick, D. G.; Stephan, D. W. Can. J . Chem. 1986, 64, 1870.
(21) Deeming, A. J .; Shinhmar, M. Unpubished results.
(22) Bodensieck, U.; Vahrenkamp, H.; Rheinwald, G.; Stoeckli-
Evans, H. J . Organomet. Chem. 1995, 488, 85.
(23) Arce, A. J .; De Sanctis, Y.; Deeming, A. J . J . Organomet. Chem.
1986, 311, 371.
(24) Deeming, A. J .; Arce, A. J .; De Sanctis, Y.; Day, M. W.;
Hardcastle, K. I. Organometallics 1989, 8, 1408.
(25) Arce, A. J .; Manzur, J .; Marquez, M.; De Sanctis, Y.; Deeming,
A. J . J . Organomet. Chem. 1991, 412, 177.
(26) Arce, A. J .; Arrojo, P.; Deeming, A. J .; De Sanctis, Y. J . Chem.
Soc., Dalton Trans. 1992, 2423.
(27) Arce, A. J .; Deeming, A. J .; De Sanctis, Y., Machado, R.;
Manzur, J .; Rivas, C. J . Chem. Soc., Chem. Commun. 1990, 1568.
(28) Meth-Cohn, O. Comprehensive Organic Chemistry; Barton, D.,
Ollis, W. D., Eds.; Pergamon Press: Oxford, U.K., 1979; Vol. 4, p 795.

788 Organometallics, Vol. 15, No. 2, 1996
Deeming et al.
Sch em e 2
F igu r e 1. ORTEP view of the cluster [Ru3H(PPh2C4H2S)-
(CO)9] (2) showing 30% ellipsoids.
chemistry in Scheme 2 is a composite of that known for
ruthenium and osmium, the intermediates being more
easily characterized for osmium than ruthenium. There
seems to be a much reduced tendency for compound 2
either to loose benzene to give [Ru3(µ3-PPh)(µ3-C4H2S)-
(CO)9] or to cleave the P-C bond to give [Ru3(µ-H)(µ-
PPh2)(µ3-C4H2S)(CO)9]. Both of these compounds are
unobserved, but as analogues of compounds C and D
in Scheme 2, they would be formed if the chemistry of
1 followed that of PPh3.
Str u ctu r es of Clu ster s 2 a n d 3. The structures of
clusters 2 and 3 were determined by single-crystal X-ray
diffraction, and Figures 1 and 2 show their structures,
respectively. Selected bond lengths and angles are in
Tables 1 and 2. Compound 2 contains the µ3-ligand Ph2-
PC4H2S bonded through the P(1) atom to Ru(3), through
a σ Ru(2)-C(2) bond and through an η2-interaction
between C(1), C(2), and Ru(1), thus forming an σ, η2-
vinyl type bridge between metal atoms Ru(1) and Ru-
(2). The structure corresponds closely to that of [Os3(µ-
H)(µ3-PMePhC6H4)(CO)9].31
F igu r e 2. ORTEP view of the cluster [Ru3H(PPh2C4H2S)-
(CO)8(Ph2PC4H3S)] (3) showing 30% ellipsoids.
solution. Figure 3 shows that two sets of ortho proton
1
signals (δ 7.13 and 7.83) in the H NMR spectrum for
these nonequivalent Ph groups coalesce at around 35
°C to give a single signal at δ 7.45 at 90 °C. The 13C-
{1H} NMR spectrum (Figure 4) shows that this is not
the result of restricted rotation about the P-Ph bonds
since there is also coalescence of the ipso phenyl 13C
resonances. The ipso signals are doublets at δ 134.9
(J PC ) 35 Hz) and 134.3 (J PC ) 61 Hz) at -70 °C which
give a single doublet at δ 135.8 (J PC ) 47 Hz) at 90 °C.
There is a temperature drift of δ, but the averaged J PC
value is as expected. There are corresponding coales-
cences of the ortho and meta signals. Our proposed
mechanism in Scheme 3 involves a hydride shift as well
as an oscillation of the σ, η2-vinyl group between two
metal centers to give a time-averaged symmetry plane.
If no other dynamic process were occurring, there would
be a pairwise exchange of carbonyls b to i leaving
carbonyl a unaffected. Indeed Figure 5 shows that all
but one of the nine CO signals in the 13C{1H} NMR
spectrum (there is accidental coincidence of two at low
temperatures) broaden above -20 °C and at room
temperature only the doublet for carbonyl a remains
sharp (δ 200.1, J PC ) 97.5 Hz). The large coupling to
The Ph groups are nonequivalent, and all nine CO
ligands are in distinguishable sites. Low-temperature
1H and 13C{1H} NMR data are consistent with the
molecular stucture found in the crystal persisting in
(29) Deeming, A. J .; Kimber, R. E.; Underhill, M. J . Chem. Soc.,
Dalton Trans. 1973, 2589. Bradford, C. W.; Nyholm, R. S. J . Chem.
Soc., Dalton Trans. 1973, 529.
(30) Brown, S. C.; Evans, J .; Smart, L. E. J . Chem. Soc., Chem.
Commun. 1980, 1021.
(31) Deeming, A. J .; Marshall, J . E.; Nuel, D.; O'Brien, G.; Powell,
N. I. J . Organomet. Chem. 1990, 384, 347. Deeming, A. J .; Kabir, S.
E.; Powell, N. I.; Bates, P. A.; Hursthouse, M. B. J . Chem. Soc., Dalton
Trans. 1987, 1529.
(32) Knox, S. A. R.; Lloyd, B. R.; Orpen, A. G.; Vinas, J . M.; Weber,
M. J . Chem. Soc., Chem. Commun. 1987, 1498.
(33) Charmont, J . P. H.; Dickson, H. A. A.; Grist, N. J .; Keister, J .
B.; Knox, S. A. R.; Morton, D. A. V.; Orpen, A. G.; Vinas, J . M. J . Chem.
Soc., Chem. Commun. 1991, 1393.

Tri- and Tetraruthenium Clusters
Organometallics, Vol. 15, No. 2, 1996 789
Ta ble 1. Bon d Len gth s (Å) a n d An gles (d eg) for 2
molecule A
molecule B
Ru(1)-Ru(2)
2.740(1)
2.832(2)
3.025(1)
2.36(1)
2.342(9)
2.10(1)
2.350(3)
1.79(1)
1.75(1)
1.71(1)
1.42(1)
1.45(2)
1.35(2)
Ru(4)-Ru(5)
2.723(1)
2.837(2)
3.036(1)
2.38(1)
2.34(1)
2.106(9)
2.361(3)
1.80(1)
1.759(9)
1.69(1)
1.40(1)
1.45(2)
1.34(2)
Ru(1)-Ru(3)
Ru(2)-Ru(3)
Ru(1)-C(1)
Ru(1)-C(2)
Ru(2)-C(2)
Ru(3)-P(1)
P(1)-C(1)
S(1)-C(1)
Ru(5)-Ru(6)
Ru(4)-Ru(6)
Ru(5)-C(5)
Ru(5)-C(6)
Ru(4)-C(6)
Ru(6)-P(2)
P(2)-C(5)
S(2)-C(5)
S(1)-C(4)
S(2)-C(8)
C(1)-C(2)
C(2)-C(3)
C(3)-C(4)
C(5)-C(6)
C(6)-C(7)
C(7)-C(8)
Ru(2)-Ru(1)-C(1)
Ru(3)-Ru(1)-C(1)
Ru(2)-Ru(1)-C(2)
Ru(3)-Ru(1)-C(2)
Ru(1)-Ru(2)-C(2)
Ru(3)-Ru(2)-C(2)
Ru(1)-Ru(3)-P(1)
Ru(2)-Ru(3)-P(1)
C(1)-S(1)-C(4)
76.0(2)
78.2(3)
48.0(2)
86.2(3)
56.0(3)
85.8(3)
73.4(1)
85.2(1)
91.1(5)
71.6(6)
120.8(8)
112.3(8)
76.0(3)
126.1(8)
125.3(7)
Ru(4)-Ru(5)-C(5)
Ru(6)-Ru(5)-C(5)
Ru(4)-Ru(5)-C(6)
Ru(6)-Ru(5)-C(6)
Ru(6)-Ru(4)-C(6)
Ru(5)-Ru(4)-C(6)
Ru(5)-Ru(6)-P(2)
Ru(4)-Ru(6)-P(2)
C(5)-S(2)-C(8)
75.7(2)
78.1(3)
48.5(2)
86.5(3)
85.7(3)
56.1(3)
73.6(1)
85.2(1)
89.6(5)
71.2(6)
122.2(7)
112.6(8)
75.4(3)
126.1(8)
124.8(9)
Ru(1)-C(1)-C(2)
P(1)-C(1)-C(2)
Ru(5)-C(5)-C(6)
P(2)-C(5)-C(6)
F igu r e 3. Variable-temperature 1H NMR spectrum for the
cluster 2 in toluene-d8 solution (* ) solvent; b ) thienyl).
S(1)-C(1)-C(2)
S(2)-C(5)-C(6)
Ru(1)-C(2)-Ru(2)
Ru(2)-C(2)-C(1)
Ru(2)-C(2)-C(3)
Ru(4)-C(6)-Ru(5)
Ru(4)-C(6)-C(5)
Ru(5)-C(6)-C(7)
Ta ble 2. Bon d Len gth s (Å) a n d An gles (d eg)
for Clu ster 3
Ru(1)-Ru(2)
Ru(1)-Ru(3)
Ru(2)-Ru(3)
Ru(1)-C(1)
Ru(1)-C(2)
Ru(2)-P(2)
Ru(2)-C(2)
Ru(3)-P(1)
P(1)-C(1)
2.734(1)
2.843(1)
3.036(1)
2.438(4)
2.314(4)
2.336(1)
2.114(4)
2.326(1)
1.783(4)
P(1)-C(101)
P(1)-C(111)
P(2)-C(5)
S(1)-C(1)
S(1)-C(4)
C(1)-C(2)
C(2)-C(3)
C(3)-C(4)
1.820(4)
1.825(4)
1.817(4)
1.762(4)
1.722(5)
1.425(5)
1.462(6)
1.331(6)
Ru(3)-Ru(1)-C(1)
Ru(2)-Ru(1)-C(2)
Ru(3)-Ru(1)-C(2)
Ru(1)-Ru(2)-P(2)
Ru(3)-Ru(2)-P(2)
Ru(3)-Ru(2)-C(2)
Ru(1)-Ru(3)-P(1)
Ru(2)-Ru(3)-P(1)
Ru(3)-P(1)-C(1)
Ru(3)-P(1)-C(101)
77.1(1)
C(1)-S(1)-C(4)
Ru(1)-C(1)-P(1)
P(1)-C(1)-S(1)
P(1)-C(1)-C(2)
S(1)-C(1)-C(2)
Ru(2)-C(2)-C(1)
Ru(1)-C(2)-C(3)
C(1)-C(2)-C(3)
C(2)-C(3)-C(4)
S(1)-C(4)-C(3)
90.4(2)
95.2(2)
48.6(1)
85.9(1)
149.9(1)
122.3(1)
84.7(1)
74.3(1)
85.5(1)
106.4(1)
113.7(2)
121.4(2)
120.8(3)
112.7(3)
127.6(3)
119.6(2)
107.8(3)
115.3(4)
113.7(3)
phosphorus confirms the assignment. At higher tem-
peratures other CO exchanges cause this signal to
coalesce. A related process was discussed for the
isomerization of diastereomers of the cluster [Os3H-
(PhSC9H14)(CO)9] (Scheme 4), although the mechanism
in that case could not be clearly established because of
other possibilities such as inversion at sulfur could not
be ruled out.34
F igu r e 4. Variable-temperature 13C{1H) NMR spectrum
for the cluster 2 in toluene-d8 solution in the phenyl region
(* ) solvent).
Sch em e 3
Cluster 3 was shown to be derived from 2 by substitu-
tion of one CO ligand by 1. The geometry of the µ3-
ligand in 3 is closely similar to that in 2. Oscillation of
the thienyl group between Ru(1) and Ru(2) would
generate another isomer, but only one was observed.
The oscillation process is quenched in this case either
because the steric bulk of the introduced tertiary
phosphines favors one orientation over the other or
because the tertiary phosphine stabilizes the σ-Ru-C
bond rather than the η2-bond at the Ru atom to which
it is bonded. This stabilization is not apparent from
differences in the corresponding Ru-C bond lengths in
2 and 3.
Th er m a l Tr ea tm en t of clu ster 2. Cluster 2 is the
main species formed from 1 and [Ru3(CO)12] after 30
min in refluxing toluene, but after 19 h only a low yield
of 2 is obtained. In addition two related tetranuclear
(34) Adams, R. D.; Qu, X.; Wu, W. Organometallics 1993, 12, 4117.

790 Organometallics, Vol. 15, No. 2, 1996
Deeming et al.
F igu r e 6. ORTEP view of the cluster [Ru4(PPh)(C4H2S)-
(CO)11] (5) showing 30% ellipsoids.
F igu r e 5. Variable-temperature 13C{1H) NMR spectrum
for the cluster 2 in toluene-d8 solution in the carbonyl
ligand region (* ) solvent, b ) thienyl).
Ta ble 3. Bon d Len gth s (Å) a n d An gles (d eg) for 5
Ru(1)-Ru(2)
Ru(1)-Ru(3)
Ru(1)-P
Ru(1)-C(2)
Ru(2)-Ru(4)
Ru(2)-P
Ru(2)-C(1)
Ru(2)-C(2)
Ru(4)-Ru(3)
Ru(4)-P
2.878(1)
2.845(1)
2.370(1)
2.113(6)
2.758(1)
2.448(1)
2.384(5)
2.416(5)
2.781(1)
2.409(1)
Ru(4)-C(1)
Ru(3)-P
2.163(5)
2.417(1)
2.323(5)
2.497(5)
1.741(5)
1.641(7)
1.431(7)
1.571(7)
1.378(9)
Sch em e 4
Ru(3)-C(1)
Ru(3)-C(2)
S-C(1)
S-C(4)
C(1)-C(2)
C(2)-C(3)
C(3)-C(4)
Ru(2)-Ru(1)-Ru(3) 82.2(1) Ru(3)-Ru(4)-P
54.9(1)
56.4(1)
54.3(1)
78.7(1)
Sch em e 5
Ru(2)-Ru(1)-P
Ru(3)-Ru(1)-P
Ru(2)-Ru(1)-C(2)
Ru(3)-Ru(1)-C(2)
54.6(1) Ru(2)-Ru(4)-C(1)
54.3(1) Ru(3)-Ru(4)-C(1)
55.4(1) P-Ru(4)-C(1)
58.3(1) Ru(1)-Ru(3)-Ru(4) 94.6(1)
Ru(1)-Ru(2)-Ru(4) 94.3(1) Ru(1)-Ru(3)-P
52.8(1)
54.7(1)
74.7(1)
49.2(1)
75.6(1)
46.0(1)
77.3(1)
74.5(1)
34.3(2)
Ru(1)-Ru(2)-P
Ru(4)-Ru(2)-P
Ru(1)-Ru(2)-C(1)
Ru(4)-Ru(2)-C(1)
P-Ru(2)-C(1)
52.1(1) Ru(4)-Ru(3)-P
54.7(1) Ru(1)-Ru(3)-C(1)
73.3(1) Ru(4)-Ru(3)-C(1)
49.1(1) P-Ru(3)-C(1)
74.0(1) Ru(1)-Ru(3)-C(2)
46.0(1) Ru(4)-Ru(3)-C(2)
79.1(1) P-Ru(3)-C(2)
Ru(1)-Ru(2)-C(2)
Ru(4)-Ru(2)-C(2)
clusters could be isolated: [Ru4(PPh)(C4H2S)(CO)11] (5)
and [Ru4(PPh)(C6H4)(CO)11] (6) (Scheme 5). Thermal
treatment of 2 in refluxing toluene gave the same
products in similar yields which were not markedly
enhanced by addition of more [Ru3(CO)12]. Cluster 6
was shown spectroscopically to be identical to a product
from the reaction of PPh3 with [Ru3(CO)12]. The X-ray
structure of 6 is known,32 but we redetermined this and
found closely corresponding structural data. The re-
cently reported structure of [Ru4(PFc)(C6H4)(CO)11] (Fc
) ferrocenyl) is very similar.35 The main structural
interest in 6 is the mode of attachment of the C6H4
ligand which is σ-bonded to two Ru atoms and η2-
coordinated to each of the other two Ru atoms. With
the C6H4 as a 6-electron donor the structure is electron-
precise with four Ru-Ru bonds which have an average
length of 2.876 Å. The IR v(CO) data for 5 and 6 are
fairly similar and both show bridging CO [ν(CO) 1852
cm-1 for 5 and 1826 cm-1 for 6], but there were
sufficient differences in the spectra to show that 5 and
6 are not isostructural. An X-ray structure of 5 was
determined to confirm this.
Ru(2)-Ru(4)-Ru(3) 85.5(1) C(1)-Ru(3)-C(2)
Ru(2)-Ru(4)-P
56.1(1)
µ4-PPh ligand on one face of a square of Ru atoms and
a µ4-C6H4 or a µ4-C4H2S ligand bonded on the opposite
face of the metal atoms. However, the thiophyne ligand
is vertical and oriented differently. Whereas the coor-
dinated C-C bond of C6H4 is parallel to a Ru-Ru edge
and the C6 plane tilted to allow two η2-contacts (dihedral
angles between the C6 and Ru4 planes ) 49.7 and 54.7°
for the two independent molecules in the crystal), the
C4H2S ligand is vertical (dihedral angle between C4S
and Ru4 planes ) 90.9°) and the coordinated C-C bond
is diagonally disposed across the Ru4 square. Cluster
5 contains two bridging CO ligands along the edges Ru-
(2)-Ru(4) and Ru(3)-Ru(4) while 6 only has one µ-CO.
The structure of 5 is structurally related to the alkyne
clusters of the type [Ru4(µ4-PPh)(µ4-alkyne)(CO)11].36,37
There are two possible orientations of the thiophyne
ligand in 5, that shown in Figure 6 and another with
the ligand rotated by 180° so that the S and C(3) atoms
are exchanged. The refinement of a disordered model
Table 3 contains selected bond lengths and angles,
and an ORTEP picture of 5 is shown in Figure 6. The
basic shapes of clusters 5 and 6 are the same with a
(36) Lunnis, J . L.; MacLaughlin, S. A.; Taylor, N. J .; Carty, A. J .;
Sappa, E, Organometallics 1985, 4, 2066.
(35) Zheng, T. C.; Cullen, W. R.; Rettig, S. J . Organometallics 1994,
13, 3594.
(37) Corrigan, J . F.; Doherty, S.; Taylor, N. J .; Carty, A. J . Orga-
nometallics 1992, 11, 3160; 1993, 12, 1365.

Tri- and Tetraruthenium Clusters
Organometallics, Vol. 15, No. 2, 1996 791
Ta ble 4. Cr ysta llogr a p h ic Da ta for Com p ou n d s [Ru 3(µ-H)(µ3-P h 2P C4H2S)(CO)9] (2),
[Ru 3(µ-H)(µ3-P h 2P C4H2S)(CO)8(P h 2P C4H3S)] (3), a n d [Ru 4(P P h )(C4H2S)(CO)11] (5)a
2
3
5
formula
M
C25H13O9PRu3S
823.62
yellow plate
0.50 × 0.43 × 0.01
triclinic
P1h
8.982(2)
17.928(5)
18.199(5)
109.69(2)
97.44(2)
89.60(2)
2734(1)
4
C40H26O8P2Ru3S2
1063.93
yellow prism
0.58 × 0.35 × 0.11
monoclinic
P21/n
10.057(1)
20.014(4)
17.858(3)
90
99.79(1)
90
3976(1)
4
1.78
13.3
C21H7O11PRu4S
902.59
red prism
0.20 × 0.20 × 0.45
monoclinic
P21/n
9.449(1)
17.926(4)
15.304(4)
90
90.84(2)
90
2592(1)
4
2.31
24.4
description
cryst size, mm3
cryst system
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, A3
Z
D
calc, g cm-3
2.00
17.9
936
µ(Mo KR), cm-1
F(000)
1400
1788
no. of unique data
no. of data used, I > 1.5σ(I)
no. of params
Rb
Rw
g
7032
5556
703
0.0501
0.0500
0.000 544
0.02
6950
6122
493
0.0338
0.0349
0.000 274
0.02
4557
4053
334
0.0324
0.0395
0.002 59
0.001
c
max shift/esd
largest residual, e A-3
0.89
0.51
0.97
a
Data common to compounds: Mo radiation (λ ) 0.710 73 Å); Nicolet R3m/v diffractometer, intensity data collected at 20 °C with scan
mode ω-2θ in the range 5 e 2θ e 50°, three check reflections, no decay, correction for Lorentz and polarization effects and for absorption
by azimuthal scan method; direct methods structure solution. R ) ∑[|Fo| - |Fc|]/∑|Fo|. c Rw ) [∑w(|Fo| - |Fc|)2/∑w|Fo| ]1/2, where w )
b
2
[σ2(Fo) + g(Fo2)]-1
.
Ta ble 5. Atom ic Coor d in a tes (×104) a n d Equ iva len t Isotr op ic Disp la cem en t P a r a m eter s (Å2 × 103) of 2
atom
x
y
z
Ueq
atom
x
y
z
Ueq
Ru(1)
Ru(2)
Ru(3)
P(1)
S(1)
C(1)
C(2)
C(3)
C(4)
4072(1)
5479(1)
3378(1)
5335(3)
5795(1)
6585(1)
5163(1)
4419(2)
4653(2)
5044(6)
5856(6)
6108(6)
5545(7)
3460(6)
3162(6)
2440(6)
2001(6)
2282(6)
3003(6)
4223(6)
4645(6)
4512(7)
3930(7)
3504(7)
3646(6)
6514(7)
6922(6)
5032(7)
4621(6)
6318(7)
6636(7)
7259(8)
7680(6)
7458(7)
7964(6)
6695(7)
6749(6)
5924(8)
6333(6)
4704(7)
4437(7)
4542(7)
4197(6)
6830(1)
8320(1)
7983(1)
7388(2)
6223(2)
6962(6)
7405(6)
7095(7)
6487(7)
6602(6)
6146(6)
5545(7)
5375(7)
5829(6)
6443(6)
8098(6)
8365(6)
8967(7)
9256(7)
8985(7)
8416(7)
7165(7)
7318(5)
5958(8)
5422(6)
6170(7)
5782(6)
9035(8)
9445(6)
8003(7)
7802(6)
9112(7)
9544(5)
8426(8)
8686(6)
8814(8)
9291(6)
7285(8)
6890(6)
30(1)
34(1)
33(1)
29(1)
41(1)
31(4)
31(4)
40(4)
45(5)
34(4)
39(4)
46(5)
47(5)
42(5)
36(4)
29(4)
38(4)
51(5)
50(5)
54(5)
44(5)
46(5)
70(4)
48(5)
87(5)
48(5)
86(6)
58(6)
86(5)
52(5)
84(5)
48(5)
75(4)
56(6)
78(5)
52(5)
89(6)
48(5)
71(4)
Ru(4)
Ru(5)
Ru(6)
P(2)
S(2)
C(5)
C(6)
C(7)
C(8)
1290(1)
1837(1)
3156(1)
1589(1)
725(1)
124(1)
-588(2)
-357(2)
42(6)
854(6)
1127(7)
545(8)
8196(1)
6716(1)
7895(1)
7354(2)
6205(2)
6919(6)
7318(6)
7035(7)
6460(7)
6600(6)
6472(6)
5894(6)
5429(7)
5538(7)
6116(6)
8108(6)
8416(7)
9052(7)
9359(8)
9056(7)
8423(7)
8849(7)
9215(6)
7824(8)
7599(6)
8998(7)
9433(5)
7028(6)
7176(5)
5877(7)
5371(5)
6039(6)
5637(6)
8291(7)
8518(6)
8740(7)
9224(6)
7197(7)
6820(5)
32(1)
29(1)
30(1)
28(1)
41(1)
31(4)
34(4)
43(5)
52(6)
32(4)
38(4)
41(5)
52(5)
48(5)
39(4)
29(4)
45(5)
57(6)
63(6)
59(6)
44(5)
54(5)
66(4)
58(6)
84(5)
41(5)
62(4)
39(5)
57(4)
46(5)
76(5)
38(4)
73(5)
47(5)
70(4)
41(5)
79(5)
42(5)
63(4)
844(3)
7340(3)
-1807(3)
-242(11)
-341(11)
-1758(12)
-2570(13)
634(11)
-717(12)
-887(13)
194(14)
1505(14)
1750(12)
-181(10)
245(13)
-384(15)
-1459(15)
-1936(15)
-1282(13)
3004(16)
4001(10)
688(15)
6199(11)
6578(11)
7815(12)
8309(12)
5114(11)
3718(12)
3615(14)
4874(14)
6238(13)
6351(12)
6781(11)
8142(12)
9156(13)
8796(14)
7436(15)
6429(13)
2551(14)
1597(11)
2912(13)
2170(13)
4767(13)
5143(11)
4204(15)
3474(12)
5949(14)
6200(13)
7173(15)
8256(11)
1923(15)
1025(11)
3407(13)
3394(12)
1752(13)
733(10)
C(101)
C(102)
C(103)
C(104)
C(105)
C(106)
C(111)
C(112)
C(113)
C(114)
C(115)
C(116)
C(11)
O(11)
C(12)
O(12)
C(13)
O(13)
C(21)
O(21)
C(22)
O(22)
C(23)
O(23)
C(31)
O(31)
C(32)
O(32)
C(33)
O(33)
C(121)
C(122)
C(123)
C(124)
C(125)
C(126)
C(131)
C(132)
C(133)
C(134)
C(135)
C(136)
C(41)
O(41)
C(42)
O(42)
C(43)
O(43)
C(51)
O(51)
C(52)
O(52)
C(53)
O(53)
C(61)
O(61)
C(62)
O(62)
C(63)
O(63)
-1568(6)
-2024(6)
-2759(6)
-3046(7)
-2616(6)
-1879(6)
-710(6)
-1308(7)
-1374(8)
-868(9)
-301(8)
-228(7)
2244(7)
2647(5)
2429(8)
2923(5)
1814(6)
1938(5)
1434(7)
1849(5)
-64(7)
-480(5)
1206(7)
1520(6)
863(7)
1250(5)
-316(7)
-573(6)
-559(7)
-949(5)
323(14)
13(13)
-852(10)
3516(13)
4563(9)
2579(14)
3128(12)
779(12)
159(10)
4895(14)
5943(10)
3552(12)
3875(12)
4397(13)
5192(9)
containing these two orientations gave a population of
0.79(1) of the rotamer shown and 0.21(1) of the other.
Spectroscopic studies of 5 in solution showed only one
isomer.
Clusters 5 and 6 have 62 and 64 valence electron
counts, respectively, and 5 could be considered to be
formally unsaturated. The different average Ru-Ru
bond lengths support this view [2.816 Å for 5 and 2.876

792 Organometallics, Vol. 15, No. 2, 1996
Deeming et al.
Ta ble 6. Atom ic Coor d in a tes (×104) a n d Equ iva len t
Ta ble 7. Atom ic Coor d in a tes (×104) a n d Equ iva len t
Isotr op ic Disp la cem en t P a r a m eter s (Å × 103) for 3
Isotr op ic Disp la cem en t P a r a m eter s (Å2 × 103) for 5
x
y
z
Ueq
x
y
z
Ueq
Ru(1)
Ru(2)
Ru(3)
P(1)
P(2)
S(1)
S(2)
S(2A)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(6A)
C(7)
2359(1)
684(1)
1245(1)
65(1)
1140(1)
1783(1)
370(1)
195(1)
2216(1)
850(1)
3412(2)
3349(3)
869(2)
1505(2)
1950(2)
1677(2)
3006(2)
3382(5)
3403(10)
3953(2)
4023(3)
-532(2)
-548(2)
-1133(3)
-1696(3)
-1696(2)
-1115(2)
106(2)
7940(1)
6887(1)
6693(1)
7646(1)
6504(1)
9183(1)
5772(2)
5869(3)
8268(2)
7974(2)
8572(2)
9204(2)
6069(2)
5978(6)
5605(11)
5518(3)
5434(3)
8196(2)
8893(3)
9230(3)
8878(4)
8183(4)
7842(3)
7363(2)
6630(3)
6417(3)
6931(3)
7655(4)
7881(3)
7294(2)
7577(3)
8207(3)
8576(3)
8317(3)
7675(3)
5777(2)
5737(3)
5138(3)
4566(3)
4584(3)
5173(2)
7256(3)
6885(2)
8509(3)
8850(2)
8663(3)
9061(2)
5959(3)
5402(2)
7321(2)
7611(2)
5961(3)
5518(2)
5992(3)
5614(2)
7141(3)
7394(2)
30(1)
29(1)
31(1)
31(1)
31(1)
46(1)
63(1)
58(1)
32(1)
30(1)
37(1)
45(2)
41(1)
63(1)
58(1)
66(2)
80(3)
37(1)
51(2)
61(2)
68(2)
67(2)
54(2)
37(1)
46(2)
62(2)
69(2)
70(2)
52(2)
41(1)
52(2)
76(2)
98(3)
80(3)
57(2)
37(1)
42(1)
66(2)
77(2)
72(2)
47(2)
45(2)
63(1)
47(2)
80(2)
45(2)
71(1)
42(1)
70(2)
40(1)
69(1)
45(2)
72(2)
48(2)
76(2)
40(1)
60(1)
Ru(1)
Ru(2)
Ru(4)
Ru(3)
P
S
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
O(11)
C(12)
O(12)
C(13)
O(13)
C(21)
O(21)
C(22)
O(22)
C(31)
O(31)
C(32)
O(32)
C(41)
O(41)
C(42)
O(42)
C(43)
O(43)
C(44)
O(44)
611(1)
3055(1)
3555(1)
1678(1)
1227(1)
5199(2)
3663(5)
2717(6)
3403(5)
4704(8)
-26(6)
-321(7)
-1318(9)
-1980(8)
-1665(7)
-697(6)
758(7)
7021(1)
6066(1)
6364(1)
7545(1)
6266(1)
7732(1)
7200(3)
7401(3)
8000(2)
8175(4)
5639(3)
5726(4)
5276(4)
4734(4)
4619(4)
5070(3)
6704(4)
6539(3)
8011(4)
8621(3)
6660(3)
6442(3)
6105(3)
6129(3)
5201(3)
4674(3)
8580(3)
9175(3)
7752(4)
7889(3)
6585(3)
6694(3)
5617(4)
5158(3)
5573(3)
5088(3)
7300(4)
7375(3)
9038(1)
8957(1)
7221(1)
7422(1)
7831(1)
8325(1)
8240(3)
8923(3)
9548(3)
9207(5)
7316(4)
6420(4)
6021(5)
6477(6)
7364(5)
7777(4)
10222(4)
10940(3)
9294(4)
9445(4)
8905(4)
8820(4)
9881(4)
10425(3)
9426(4)
9706(4)
7385(5)
7386(4)
7011(4)
6802(4)
6765(4)
6468(4)
6357(4)
5851(3)
8119(4)
8104(3)
6301(4)
5550(3)
28(1)
28(1)
30(1)
28(1)
27(1)
40(1)
30(1)
35(2)
54(1)
59(2)
35(2)
51(2)
65(3)
67(3)
61(3)
46(2)
48(2)
69(2)
48(2)
76(2)
41(2)
65(2)
45(2)
69(2)
44(2)
74(2)
46(2)
82(2)
47(2)
82(2)
42(2)
74(2)
47(2)
80(2)
39(2)
59(2)
44(2)
68(2)
-1309(1)
-71(1)
-2629(3)
-25(4)
332(4)
356(3)
142(4)
-102(4)
-1306(4)
-329(11)
-2433(20)
-631(6)
-1899(7)
495(4)
C(8)
C(101)
C(102)
C(103)
C(104)
C(105)
C(106)
C(111)
C(112)
C(113)
C(114)
C(115)
C(116)
C(121)
C(122)
C(123)
C(124)
C(125)
C(126)
C(131)
C(132)
C(133)
C(134)
C(135)
C(136)
C(11)
O(11)
C(12)
O(12)
C(13)
O(13)
C(21)
O(21)
C(22)
O(22)
C(31)
O(31)
C(32)
O(32)
C(33)
O(33)
778(6)
47(7)
1290(5)
1662(5)
1246(6)
477(6)
-244(6)
-1325(6)
-2432(5)
4393(7)
5230(6)
2322(6)
1804(6)
2207(7)
2549(7)
-151(7)
-1287(5)
5385(6)
6450(5)
3303(7)
3146(7)
4437(6)
5247(5)
2515(7)
2615(6)
99(5)
-1622(4)
-2210(4)
-3488(5)
-4198(5)
-3638(5)
-2352(4)
-2165(4)
-2777(4)
-3317(5)
-3242(6)
-2625(6)
-2074(5)
-2446(4)
-3765(4)
-4556(5)
-4111(6)
-2888(6)
-2009(5)
3375(4)
4078(3)
3414(5)
4147(4)
2967(4)
3406(4)
1256(4)
1621(4)
1327(4)
1744(4)
2305(4)
2928(4)
263(5)
255(2)
202(3)
-12(3)
-170(3)
-111(2)
2345(2)
1839(3)
1925(4)
2502(5)
3003(4)
2941(3)
1820(2)
1875(2)
1640(3)
1343(3)
1278(3)
1495(2)
1426(2)
1590(2)
527(2)
at -10 °C. The red mixture was stirred at 5 °C for 20 min
and cooled to -70 °C, and a solution of Ph2PCl (7 mL, 0.0382
mol) in dry diethyl ether (20 mL) was added dropwise. The
colorless reaction mixture turned light brown on warming to
20 °C and was hydrolyzed after 30 min with saturated aqueous
ammonium chloride (50 mL). The diethyl ether layer was
separated, dried (Mg2SO4), and evaporated to give a light
brown solid, which was recrystallized from ethanol to give off-
white crystals (5.63 g, 0.0210 mol, 55%), mp 43-46 °C (lit.
36-38 °C15 and 44-46 °C13). Anal. Calcd for C16H13PS: C,
71.62; H, 4.88; P, 11.54; S, 11.95. Found: C, 71.25; H, 4.84;
P, 11.96; S, 11.67. The parent molecular ion was observed in
the mass spectrum (EI). 1H NMR: δ 7.58 (dd, J ) 4.9, 0.9,
1H), 7.4-7.3 (m, 11H), 7.13 (ddd, J ) 4.8,3.4,1.2, 1H). 13C-
{1H} NMR (CDCl3): δ 137.9 (d, J ) 27.3 Hz), 137.8 (d, J ) 8.1
Hz), 136.3 (d, J ) 26.4 hz), 133.0 (d, J ) 19.7 Hz), 132.0 (s),
128.6 (d, J ) 37.9 Hz), 128.4 (s), 128.0 (d, J ) 8.0 Hz). 31P-
{1H} NMR: δ -20.9 (s). These data differ somewhat from
those reported.13 The identity of 1 was checked by the
preparation of [Ph2MePC4H3S)]I by reaction of it with methyl
iodide in methanol. Addition of diethyl ether gave colorless
crystals of the phosphonium iodide (0.158 g, 48%). Anal.
Calcd for C17H16IPS: C, 49.77; H, 3.93; P, 7.55; S, 7.81.
Found: C, 50.24; H, 3.81; P, 7.70; S, 7.64. 1H NMR: δ 8.16
(dt, J ) 0.9, 4.7 Hz, 1H), 8.01 (ddd, J ) 0.9, 3.8, 8.1 Hz, 1H),
7.82-7.77 (m, 6H), 7.70-7.66 (m, 4H), 7.46 (ddd, J ) 2.1, 3.8,
4.7 Hz, 1H), 3.21 (d, J ) 13.4 Hz, 3H).
201(2)
1797(2)
2187(2)
1950(2)
2042(2)
2557(2)
3016(2)
607(2)
696(2)
-201(2)
-593(2)
-242(2)
-620(2)
-259(4)
2441(4)
3134(3)
Å for 6]. However, in spite of its lower electron count,
cluster 5 does not react with CO under mild conditions.
Exp er im en ta l Section
[Ru3(CO)12] was purchased from Aldrich plc. TLC separa-
tions were carried out on laboratory prepared 1 mm layers of
silica [HF254 (type 60), Merck]. IR spectra were recoded on a
Perkin-Elmer 983 spectrometer; H, 13C, and 31P NMR were
1
recorded for CDCl3 solutions (unless stated otherwise) using
a Varian VXR400 spectrometer. Analyses were determined
in the analytical laboratory at UCL, and mass spectra were
recorded on a VG ZAB-8E mass spectrometer.
Syn th esis of Dip h en yl-2-th ien ylp h osp h in e (1). Using
a method modified from that reported,14 BuLi (0.0592 mol) in
diethyl ether (37 mL) was added to a solution of thiophene
(4.75 mL, 0.0593 mol) in dry diethyl ether (150 mL) under N2
Rea ction of [Ru 3(CO)12] w ith 1. A solution of [Ru3(CO)12]
(0.0503 g, 7.87 × 10-5 mol) and the tertiary phosphine 1
(0.0215 g, 8.02 × 10-5 mol) in toluene (12.5 mL) was refluxed
under nitrogen for 30 min to give a dark orange solution.
Removal of the solvent and preparative TLC workup [SiO2,
eluent dichloromethane-light petroleum (bp 30-40 °C) (v/v
) 1:20)] gave the cluster [Ru3H(Ph2PC4H2S)(CO)9] (2) as
orange crystals (0.0383 g, 4.65 × 10-5 mol, 59%), recovered

Tri- and Tetraruthenium Clusters
Organometallics, Vol. 15, No. 2, 1996 793
[Ru3(CO)12] (0.0028 g, 4.38 × 10-6 mol), and [Ru3H(Ph2-
PC4H2S)(CO)8(Ph2PC5H3S)] (3) (0.0081 g, 7.61 × 10-6 mol,
10%). Compound 2: parent molecular ion observed in the FAB
ν(CO) (cm-1) (cyclohexane): 2084 w, 2050 s, 2041 vs, 2026 s,
2023 s, 2007 vw, 1996 m, 1986 w, 1979 w, 1826 w. The crystal
structure was determined and shown to be essentially as
reported previously. Partially characterized product: 1H NMR
δ 9.25 (dd, J ) 2.1, 5.3 Hz, 1H), 7.69 (m, 2H), 7.53-7.38 (m,
8H), 6.51 (ddd, J ) 2.3, 3.3, 5.4 Hz, 1H), 5.40 (dt, J ) 10.3,
2.2 Hz, 1H); 31P{1H} NMR δ 13.5 (s); ν(CO) (cm-1) (cyclohex-
ane) 2077 s, 2032 vw, 2046 vs, 2015 s, 2005 s, 1993 s, 1972 w,
1945 m.
X-r a y Str u ctu r e Deter m in a tion s: Suitable crystals of
compounds 2, 3, and 5 were examined by similar procedures.
The crystal was fixed to a glass fiber mounted on a goniometer
on a Nicolet R3v/m diffractometer. Cell constants and an
orientation matrix were obtained from least squares refine-
ment of 30 reflections (13 e 2θ e 26°) for 2, 28 reflections (16
e 2θ e 29°) for 3, and 35 reflections (13 e 2θ e 29°) for 5.
Details of the crystal data for the three compounds are in Table
4. Data were collected by the ω-2θ method for 2 and 5 and
by the ω method for 3 in the 2θ ranges 5 e 2θ e 45° for 2 and
5 e 2θ e 50° for the other crystals. Three standard reflections
monitored every 100 reflections showed only small variations
in intensity. Lorentz and polarization corrections were applied
as was an empirical absorption correction (Ψ-scan method).
Maximum and minimum transmission coefficients: 1.000 and
0.798 for 2, 0.976 and 0.787 for 3, and 0.876 and 0.838 for 5.
Structures were solved by direct methods and refined using
difference Fourier techniques. All non-hydrogen atoms were
refined anisotropically, and H-atoms bonded to carbon were
included in idealized positions and allowed to ride on the C
atoms with C-H distances set at 0.96 Å and isotropic thermal
parameters at 0.08 Å3. The hydride ligand in 3 but not that
in 2 was located.
Some disorder was found for the 2-thienyl group of the Ph2-
PC4H3S ligand of 3 which was refined in two orientations, that
shown in Figure 2 and another with a 180° rotation about the
P(2)-C(5) bond. The sulfur atoms for the two orientations S(2)
and S(2A) were refined isotropically, and the corresponding
carbon atoms C(6) and C(6A), similarly with thermal param-
eters fixed to be the same as the sulfur atoms. The best refined
populations, 0.658 for S(2) and C(6) and 0.342 for S(2A) and
C(6A), were fixed in the final cycles of refinement.
Some disorder was also found for the C4H2S ligand in cluster
5 which was found with the orientation as shown in Figure 6
and the reverse orientation with atoms S and C(3) replaced
by atoms C(3A) and S(A). The refined populations of these
disordered orientations were 0.79(1) and 0.21(1), respectively,
and these values were fixed in the final cycles of refinement.
Atoms S and C(3a) were refined with the same positional and
thermal parameters and likewise atoms S(A) and C(3). No
hydrogen atoms were included for the disordered C4H3S group
of 3 or the C4H2S group of 5.
1
mass spectrum; H NMR (27 °C) δ 7.27 (dd, J ) 5.0, 1.6 Hz,
1H), 7.35 (d, J ) 5.0Hz, 1H), broad signals at 7.55 (4H), 7.96
(2H) and 7.25 (4H), -17.65 (d, J ) 18.4 Hz, 1H); (toluene-d8,
-20 °C): δ 7.83 (dd, J ) 7.6, 11.4 Hz,2H), 7.13 (dd, J ) 7.9,
11.2 Hz, 2H), 7.05-7.01 (m, 2H), 6.90-6.69 (m, 5H), 6.39 (d,
J ) 0.6 Hz, 1H); 13C{1H} NMR (toluene-d8, -70 °C) δ 175.5
(d, J ) 32.1 Hz), 143.5 (d, J ) 13.9 Hz), 134.9 (d, J ) 35.0
Hz), 134.3 (d, J ) 61.2 Hz), 133.8 (s), 133.2 (d, J ) 11.5 Hz),
131.6 (d, J ) 10.2 Hz), 131.1 (d, J ) 8.2 Hz), 81.5 (d, J ) 53.4);
31P{1H} NMR δ 44.0 (s); ν(CO) (cm-1) (cyclohexane) 2086 s,
2058 s, 2032 vs, 2021 s, 2005 m, 1998 s, 1972 m. Compound
3: Anal. Calcd for C40H26O8P2Ru3S2: C, 45.16; H, 2.46; P, 5.82;
S, 6.03. Found: C, 43.94; H, 2.28; P, 6.08; S, 5.79. The parent
molecular ion was observed in the FAB mass spectrum. 1H
NMR: δ 7.90 (m, 2H), 7.63 (m, 1H), 7.48 (m, 2H), 7.40 (m,
1H), 7.21 (m, 3H), 7.15-7.00 (m, 8H), 6.98 (d, J ) 5.1 Hz, 1H),
6.92 (m, 2H), 6.75-6.66 (m, 4H), 6.44 (d, J ) 3.7 Hz, 1H),
-17.19 (dd, J ) 20.1,10.0 Hz, 1H). 31P{1H} NMR: δ 31.4 (dd,
J PP ) 24.8, J PH ) 5.8 Hz), 39.9 (dd, J PP ) 24.9, J PH ) 12.0 Hz)
(residual coupling to the hydride ligand was observed). ν(CO)
(cm-1) (cyclohexane): 2071 s, 2067 sh, 2032 vs, 2018 s, 2000
m, 1991 m, 1968 m.
Su bstitu tion of 2 by Ter tia r y P h osp h in e 1. A solution
of the nonacarbonyl cluster 2 (0.0488 g, 5.93 × 10-5 mol) and
ligand 1 (0.0193 g, 7.19 × 10-5 mol) in hexane (25 mL) was
refluxed under nitrogen for 1 h leading to a color change from
orange to red. Removal of the solvent and preparative TLC
workup [SiO2, eluent dichloromethane-light petroleum (bp
30-40 °C) (v/v, 1:5)] gave one main orange band which yielded
the product 3 as orange crystals (0.0417 g, 3.92 × 10-5 mol,
66%), characterized analytically and spectroscopically as the
same compound described above.
Tr ea tm en t of Clu ster 2 w ith CO. A solution of the
cluster 2 (0.0840 g, 1.02 × 10-4 mol) in heptane (20 mL) was
saturated with CO gas (1 atm) and sealed in a glass tube which
was heated at 80 °C for 42 h. The tube was opened, the solvent
removed, and the residue treated by preparative TLC [SiO2,
eluent dichloromethane-light petroleum (bp 30-40 °C) (v/v,
1:20)] to give one main orange band which gave a red oil on
removal of the solvent. This was characterized by IR, 1H NMR,
and MS as [Ru3(CO)11(Ph2PC4H3S)] (4) (0.0706 g, 8.03 × 10-5
mol, 79%). ν(CO) (cm-1) (cyclohexane): 2098 s, 2048 s, 2033
m, 2026 m, 2017 vs, 2005 w, 1998 w, 1988 w, 1973 w. 1H
NMR: δ 7.64 (m, 1H), 7.48-7.39 (m, 10H), 7.35 (s, 1H) and
7.17 (m, 1H). 31P{1H} NMR: δ 21.0 (s). Compound 4 is
moderately unstable in solution and in refluxing heptane
under nitrogen converted quantitatively to cluster 2 in less
than 20 min. There was no indication of any other product.
All calculations were carried out on a MicroVax II computer
running SHELXTL-PLUS.38 The final refinement parameters
are in Table 4, selected bond lengths and angles for 2, 3, and
5 are in Tables 1-3, and atomic coordinates for these com-
pounds are in Tables 5-7. Anisotropic thermal parameters
and full sets of bond lengths and angles have been deposited
as Supporting Information.
Th er m olysis of Clu ster 2. Cluster 2 was prepared in situ
from [Ru3(CO)12] (0.258 g, 4.03 × 10-4 mol) and ligand 1 (0.109
g, 4.06 × 10-4 mol) in toluene (75 mL) as described above, and
the reflux was extended to 19 h. The solvent was removed
and the mixture separated by column chromatography [SiO2,
eluent dichloromethane-light petroleum (bp 30-40 °C) (v/v
1:7.5 and then 1:2.5)]. The main bands were further separated
by TLC [SiO2, eluent dichloromethane-light petroleum (bp
30-40 °C) (v/v 1:20)] to give four compounds: red crystals of
[Ru4(µ4-PPh)(µ4-C4H2S)(CO)11] (5) (0.0127 g, 1.41 × 10-5 mol,
4%), red crystals of [Ru4(µ4-PPh)(µ4-C6H4)(CO)11] (6) (0.0208
g, 2.32 × 10-5 mol, 6%), cluster 2 (0.031 g, 3.76 × 10-5 mol,
9%), and a partially characterized compound (0.0243 g).
Cluster 5: Anal. Calcd for C21H7O11PRu4S: C, 27.95; H, 0.78;
P, 3.43. Found: C, 28.02; H, 0.93; P, 3.15. 1H NMR: δ 7.27
(d, J ) 5.0 Hz, 1H), 7.21-7.14 (m, 3H), 6.97 (d, J ) 5.0 Hz,
1H), 6.59 (dd, J ) 6.7, 14.8 Hz, 2H). 31P{1H} NMR: δ -47.4
(s). ν(CO) (cm-1) (cyclohexane): 2085 w, 2052 s, 2040 vs, 2031
s, 2021 w, 2003 m, 1985 m, 1851 w. Cluster 6: 1H NMR: δ
7.50-7.41 (m, 5H), 6.93 (m, 2H), 6.33 (m, 2H). 13C{1H}
NMR: δ ca. 200 (broad singlet), 144.8 (d, J ) 5.4 Hz), 132.9
(d, J ) 13.9 Hz), 132.3 (s), 128.3 (m), 119.7 (d, J ) 3.8 Hz).
Ack n ow led gm en ts. We thank the SERC for fund-
ing toward the diffractometer, the University of London
Central Research Fund for the purchase of ruthenium
carbonyl, and the Royal Society, the British Council, and
CONICIT (Venezuela) for support for this collaboration.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, H atom positions and U values, anisotropic thermal
parameters, and bond distances and angles (25 pages). Order-
ing information is given on any current masthead page.
OM9503205
(38) Sheldrick, G. M. SHELXTL-PLUS, Package for crystal structure
determination, University of Go¨ttingen, Germany, 1986.