Reactions of the trinuclear cluster (μ2-H)Ru3 (CO)9(μ3,η2-SCNHPhNPh): Synthesis and molecular structure of Ru3(CO)6(PPh3)(μ 2,η2-C6H5)-(μ2PPh 2)(μ3-S),

Article abstract of DOI:10.1021/om9507383

Reactions of the previously isolated trinuclear cluster (μ₂-H)Ru₃(CO)₉(μ₃,η ²-SCNHPhNPh) (1) with excess diphenylthiourea result in cluster fragmentation to produce the mononuclear complex Ru(CO)₂(η²-SCNHPhNPh)₂ (2) containing two bidentate diphenylthioureato ligands. Room-temperature reactions of 1 with 1 or 2 equiv of triphenylphosphine result in substitution of one or two carbonyl groups, respectively, to give the clusters (μ₂-H)Ru₃(CO)₈-(PPh₃)(μ ₃,η²-SCNHPhNPh) (3) and (μ₂-H)Ru₃(CO)₇(PPh₃) ₂(μ₃,η²-SCNHPhNPh) (4). An X-ray crystal structure analysis shows 3 to represent a monosubstituted derivative of 1 with the PPh₃ ligand occupying an equatorial position on one of the two bridgehead ruthenium atoms; the crystal belongs to the triclinic space group P1?; Z = 2, a = 10.014(2) A?, b = 14.449(4) A?, c = 14.573(4) A?, α = 100.38(2)°, β = 98.70(2)°, and γ = 107.20(2)°. Thermolysis of either 1 in the presence of 2 equiv of PPh₃, or of 4 alone, gives the sulfur-capped, trinuclear cluster Ru₃(CO)₇(PPh₃)(μ₂,η ²-C₆H₅)(μ₂-PPh ₂)(μ₃-S) (5). X-ray structural analysis of 5 shows a diphenylphosphido bridge and a phenyl bridge resulting from P-C bond activation of a PPh₃ group and C-H activation of the aryl group; crystals of 5 are monoclinic, space group P2₁/n; Z = 4, a = 10.824(1) A?, b = 19.193(5) A?, c = 20.953(2) A?, and β = 97.44(1)°. Diphenylphosphinoethane (dppe) is found to replace two carbonyl ligands on two adjacent Ru atoms to give the cluster (μ₂-H)Ru₃(CO)₇(Ph₂PCH ₂CH₂PPh₂)- (μ₃,η²-SCNHPhNPh) (6) whose X-ray structural analysis shows a dppe ligand bound cis to the μ₂-8 of the diphenylthioureato ligand and cis to the μ₂-H ligand. Crystals of 6 are monoclinic, space group P2₁/n; Z = 4, a = 17.667(7) A?, b = 17.681(5) A?, c = 18.049(4) A?, and β = 108.06(2)°.

Full text of DOI:10.1021/om9507383

704
Organometallics 1996, 15, 704-712
Rea ction s of th e Tr in u clea r Clu ster
(µ2-H)Ru 3(CO)9(µ3,η2-SCNHP h NP h ): Syn th esis a n d
Molecu la r Str u ctu r e of Ru 3(CO)6(P P h 3)(µ2,η2-C6H5)-
(µ2-P P h 2)(µ3-S), a Com p lex Con ta in in g a P h en yl Liga n d
w ith a Ra r e σ,π-Coor d in a tion Mod e†
Lisa A. Hoferkamp, Gerd Rheinwald, Helen Stoeckli-Evans, and
Georg Su¨ss-Fink*
Institut de Chimie, Universite´ de Neuchaˆtel, Avenue de Bellevaux 51,
CH-2000 Neuchaˆtel, Switzerland
Received September 15, 1995X
Reactions of the previously isolated trinuclear cluster (µ2-H)Ru3(CO)9(µ3,η2-SCNHPhNPh)
(1) with excess diphenylthiourea result in cluster fragmentation to produce the mononuclear
complex Ru(CO)2(η2-SCNHPhNPh)2 (2) containing two bidentate diphenylthioureato ligands.
Room-temperature reactions of 1 with 1 or 2 equiv of triphenylphosphine result in
substitution of one or two carbonyl groups, respectively, to give the clusters (µ2-H)Ru3(CO)8-
(PPh3)(µ3,η2-SCNHPhNPh) (3) and (µ2-H)Ru3(CO)7(PPh3)2(µ3,η2-SCNHPhNPh) (4). An X-ray
crystal structure analysis shows 3 to represent a monosubstituted derivative of 1 with the
PPh3 ligand occupying an equatorial position on one of the two bridgehead ruthenium atoms;
the crystal belongs to the triclinic space group P1h; Z ) 2, a ) 10.014(2) Å, b ) 14.449(4) Å,
c ) 14.573(4) Å, R ) 100.38(2)°, â ) 98.70(2)°, and γ ) 107.20(2)°. Thermolysis of either 1
in the presence of 2 equiv of PPh3, or of 4 alone, gives the sulfur-capped, trinuclear cluster
Ru3(CO)7(PPh3)(µ2,η2-C6H5)(µ2-PPh2)(µ3-S) (5). X-ray structural analysis of 5 shows a
diphenylphosphido bridge and a phenyl bridge resulting from P-C bond activation of a PPh3
group and C-H activation of the aryl group; crystals of 5 are monoclinic, space group P21/n;
Z ) 4, a ) 10.824(1) Å, b ) 19.193(5) Å, c ) 20.953(2) Å, and â ) 97.44(1)°. Diphenylphos-
phinoethane (dppe) is found to replace two carbonyl ligands on two adjacent Ru atoms to
give the cluster (µ2-H)Ru3(CO)7(Ph2PCH2CH2PPh2)- (µ3,η2-SCNHPhNPh) (6) whose X-ray
structural analysis shows a dppe ligand bound cis to the µ2-S of the diphenylthioureato ligand
and cis to the µ2-H ligand. Crystals of 6 are monoclinic, space group P21/n; Z ) 4, a )
17.667(7) Å, b ) 17.681(5) Å, c ) 18.049(4) Å, and â ) 108.06(2)°.
In tr od u ction
(CO)9(µ2-H){(µ3-S)Ru(CO)3(η2-CH2CMe2NHCNHtBu)},
were isolated in which not only C-S bond breaking of
the thiourea is observed but also C-H activation of one
of the tert-butyl groups.1d Thus the nature of the
thiourea substituent R has a strong influence on the
type of cluster formed. This is most likely a result of
stabilization of one of the tautomeric forms of the
thiourea by the substituent R. Among the trinuclear
clusters containing the thiourea ligands in a µ3,η2-face-
capping mode, the cluster in which R ) Ph, (µ2-H)(Ru3-
(CO)9(µ3,η2-SCNPhNPhH) (1) could be isolated in a
The reactions of thioureas SC(NR1R2)2 with triruthe-
nium dodecacarbonyl were first studied in this labora-
tory and produced a series of new and unique cluster
complexes.1 Trinuclear complexes of the type (µ2-H)-
(Ru3(CO)9(µ3,η2-RNCSNRH) were obtained from the
reaction of Ru3(CO)12 with thiourea (R ) H) and its
dimethyl and diphenyl derivatives (R ) Me, Ph).1a In
the case of diethylthiourea, in addition to the analogous
trinuclear cluster Ru3(CO)9(µ2-H)(µ3,η2-EtNCSNHEt),
the tetranuclear clusters Ru4(CO)8-n(µ2-CO)3(µ4-S)2-
{C(NRH)}n (n ) 1, 2) (R ) Et) were isolated.1b With
diisopropylthiourea, the sole products were tetranuclear
clusters of the same type (R ) i-Pr).1c In the reaction
of Ru3(CO)12 with di-tert-butylthiourea, two complexes,
Ru3(CO)8(µ2-H)-(µ3-S)(η2-CH2CMe2NHCNHtBu) and Ru3-
† Dedicated to Professor Max Herberhold on the occasion of his 60th
birthday.
X Abstract published in Advance ACS Abstracts, December 15, 1995.
(1) (a) Bodensieck, U.; Stoeckli-Evans, H.; Su¨ss-Fink, G. Chem. Ber.
1990, 123, 1603. (b) Bodensieck, U.; Santiago, J .; Stoeckli-Evans, H.;
Su¨ss-Fink, G. J . Chem. Soc., Dalton Trans. 1992, 255. (c) Bodensieck,
U.; Stoeckli-Evans, H.; Su¨ss-Fink, G. J . Organomet. Chem. 1992, 433,
149. (d) Bodensieck, U.; Stoeckli-Evans, H.; Su¨ss-Fink, G. J . Chem.
Soc., Chem. Commun. 1990, 267. (e) Bodensieck, U.; Meister, G.;
Stoeckli-Evans, H.; Su¨ss-Fink, G. J . Chem. Soc., Dalton Trans. 1992,
2131. (f) Bodensieck, U.; Stoeckli-Evans, H.; Su¨ss-Fink, G. Angew.
Chem. 1991, 103, 1147; Angew. Chem., Int. Ed. Engl. 1991, 30, 1126.
relatively high yield (59%) and was found to be rela-
tively stable toward air. Given that thioureas are of
interest, owing to the proven catalytic activity of thio-
0276-7333/96/2315-0704$12.00/0 © 1996 American Chemical Society

Trinuclear Cluster (µ2-H)Ru3(CO)9(µ3,η2-SCNHPhNPh)
Organometallics, Vol. 15, No. 2, 1996 705
urea-palladium complexes,2 and investigations of the
substitution reactions of their cluster complexes can
often provide useful information regarding intermedi-
ates as well as mechanistic details of homogeneous
catalytic processes, a reactivity study of 1 was under-
taken.
nH2O. The chlorocarbonyl complex thus formed was
then allowed to react with the thione. However, at-
tempts at the same procedure to afford 2 were found to
give very low yields. The postulated mechanism in
the reaction with RuCl3‚nH2O proposes a six-coordinate
intermediate “Ru(CO)2(Cl)2(pySH)2”, wherein the pySH
ligand is sulfur-bound and a proton resides on the ring
nitrogen, that undergoes elimination of HCl via the
chloride ligands cis to the pySH ligands to give the
product. The less acidic nature of the NH protons of
thiourea relative to the pyridinium proton is probably
a contributing factor to the low yields obtained in
similar reactions using diphenylthiourea. Furthermore,
considering that formation of 2 occurs in better yields
from reactions of Ru3(CO)12 as well as of 1 with excess
diphenylthiourea, it follows that the trinuclear species
1 is a more productive precursor (as compared to the
six-coordinate intermediate suggested above) in the
formation of 2.
Resu lts a n d Discu ssion
Rea ction of (µ2-H)(Ru 3(CO)9(µ3,η2-SCNP h NP h H)
(1) w ith Excess Dip h en ylth iou r ea . Stirring a room-
temperature THF solution of 1 with excess diphenyl-
thiourea over an extended period (4 days) resulted in
formation of the mononuclear species Ru(CO)2(SCNH-
PhNPh)2 (2) in 15.4% yield. This compound could also
Rea ction s of (µ2-H)Ru 3(CO)9(µ3,η2-SCNHP h NP h )
(1) w it h Tr ip h en ylp h osp h in e. Stirring a THF
solution of 1 with 1 or 2 equiv of PPh3 over a period of
24 h resulted in substitution of one or two carbonyl
groups to produce the 48-electron trinuclear clusters (µ2-
H)Ru3(CO)8(PPh3)(µ3,η2-SCNHPhNPh) (3) and (µ2-H)-
be produced in long-term reactions of Ru3(CO)12 with
excess diphenylthiourea (yield 23.4%). The mononu-
clear complex 2 was isolated from the reaction mixture
by TLC as a colorless band and could be recrystallized
from mixed-solvent systems (CH2Cl2/hexane). IR and
1H NMR data are consistent with a mononuclear system
containing two intact diphenylthioureato ligands. The
presence of an M+ peak at 612 mass units in FAB mass
spectra of 2 further support this assignment. An
independently published, X-ray structural analysis of
the Os analogue, Os(CO)2(pySH)2,3 showed the CO
ligands to occupy cis positions and the sulfur ligands to
occupy trans positions on a central Os atom. The
appearance of two bands in the νCO region of the IR
spectrum of 2 indicates a species of C2 symmetry
requiring the two carbonyl ligands to be placed in a cis
orientation. The valence requirements of the central
Ru atom in 2 are fulfilled if the bidentate diphenyl-
thioureato fragment is considered as a four-electron
donor. This should result in decreased sp2 character
at the central C of the NCN portion of the ligand as
compared to the trinuclear cluster 1 wherein the ligand
serves as a five-electron donor. This aspect is supported
by the observed low-energy shift of the νNCN stretch in
Ru3(CO)7(PPh3)2(µ3,η2-SCNHPhNPh) (4), respectively.
If an excess of PPh3 was used, no further substitution
was observed. Clusters 3 and 4 could be separated from
the reaction mixture using preparative TLC, eluting as
two distinct orange bands. However, 1H NMR spec-
troscopy of the products isolated from the plates showed
the presence of 4 in samples of 3 and vice versa. Pure,
crystalline samples of 3 could be obtained by crystal-
lization from CH2Cl2/hexane solvent mixtures. Spectral
data for the clusters 3 and 4, as summarized in the
Experimental Section, provide important information
concerning the nature of the carbonyl substitutions
taking place on cluster 1. The upfield shifts of the
phosphorus signals in 31P NMR spectra of 3 and 4
indicate the phosphine ligand is bound to the metal
through a σ-bond. This conclusion is also corroborated
IR spectra of 2 as well as a high-energy shift for νNH
.
Mononuclear complexes analogous to 2 have also been
isolated from reactions of Ru3(CO)12 and pyridine-2-
thione (pySH), but in contrast to the diphenylthioureato
derivative described here, vigorous conditions were
required to produce the complex Ru(CO)2(η2-pySH)2.4 An
alternative synthesis was outlined for the pySH ana-
logue of 2 involving reductive carbonylation of RuCl3‚
1
by the integrals of the H NMR spectra, showing intact
PPh3 groups. The placement of the phosphine ligands
on the cluster adjacent to the bridging hydride can be
deduced from the presence of fine structure at the
signals of the hydride ligands; a doublet is observed in
spectra of 3 while a triplet is observed in spectra of 4.
Furthermore, the small values of the coupling constants
indicate a cis orientation of the coupling groups.5 From
the presence of NH and NCN bands in solid-state IR
(2) (a) Chiusoli, G. P.; Costa, M.; Pergreffi, P. L.; Reverberi, S.;
Salerno G. Gazz. Chim. Ital. 1985, 115, 691. (b) Chiusoli, G. P.; Costa,
M.; Masarati, E.; Salerno, G. J . Organomet. Chem. 1983, 255, C35.
(3) Deeming, A. J .; Meah, M. N.; Randle, N. P. J . Chem. Soc., Dalton
Trans. 1989, 2211.
1
spectra as well as the integrals of the H NMR spectra
in the phenyl region, it is clear that the diphenylthio-
(4) (a) Deeming, A. J .; Karim, M. Polyhedron 1991, 10, 837. (b)
Andreu, P. L.; Cabeza, J . A.; Ferna´ndez-Colinas, J . M.; Riera, V. J .
Chem. Soc., Dalton Trans. 1990, 2927.
(5) Aime, S.; Gobetto, R.; Osella, D.; Milone, L.; Rosenberg, E.
Organometallics 1982, 1, 640.

706 Organometallics, Vol. 15, No. 2, 1996
Hoferkamp et al.
Within the S-C-N base of the diphenylthioureato
ligand, substitution at the metal framework has little
effect; the bond distances and angles there remain
essentially unchanged. However, the Ru3-N1 bond is
approximately 0.02 Å shorter in 3 (Ru1-N1, 2.167(3)
Å in 1 vs Ru3-N1, 2.149(5) Å in 3). This shorter bond
length does not change the Ru3-N1-C1 bond angle,
nor does it influence the remaining structural features
of the diphenylthioureato ligand.
In the formation of the disubstituted cluster 4, the
second PPh3 ligand is assumed to coordinate to the
second sulfur-bonded Ru atom. The structure of the
disubstituted PPh3 ampy cluster, (µ2-H)Ru3(CO)7(PPh)2-
(µ3,η2-ampy), has been reported by Cabeza et al.8 There
the two phosphine groups occupy equatorial positions
on the nitrogen-bridged Ru atoms. The infrared data
given for the Cabeza cluster show a νCO structure
analogous to that of 4 as well as J (µ-H)-P coupling
constants of the same order (8.3 Hz) as those found in
spectra of 4. Based on these observations, the two
clusters can be assumed isostructural.
Cabeza et al. also presented a trinuclear complex
containing a µ3,η2-face-capping ligand derived from
2-mercaptobenzimidazolate (mbim) in which two car-
bonyl groups are substituted with PPh3 ligands.6a Like
the diphenylthioureato derivative, this compound was
prepared via room-temperature reaction of the starting
trinuclear cluster and PPh3. However, the disubstituted
mbim cluster proved impossible to separate from its
monosubstituted counterpart and was therefore never
fully characterized.
F igu r e 1. Molecular structure of 3; only the ipso-carbon
atoms of the PPh3 ligand are shown.
ureato ligand is undisturbed by substitution at the
metal skeleton. Cabeza et al. prepared several phos-
phine and phosphite derivatives of trinuclear clusters
containing the 2-amino-6-methylpyridinato (ampy) cap-
ping ligand,6 as well as the pyridine-2-thiol (pyS)
ligand.7 These reactions produced clusters similar to 3
and 4; however, no monosubstituted derivatives were
structurally characterized.
The structure of cluster 3 was determined by X-ray
structural analysis. The molecule crystallizes in the
triclinic crystal system, in the space group P1h with two
molecules per unit cell. The molecular structure of 3 is
shown in Figure 1. Crystal data are collected in Table
1, Table 2 gives the atomic coordinates, and Table 3
gives selected bond distances and angles for 3.
Refluxing a toluene solution of 1 with 2 equiv of PPh3
produced the trinuclear cluster Ru3(CO)7(µ2-Ph)(µ2-
PPh2)(PPh3)(µ3-S) (5). Similar results were obtained
The triangular metal framework of cluster 3, com-
pared to that of 1, is slightly perturbed by the presence
of the PPh3 ligand. In cluster 1 a mirror plane extends
through Ru1 and the midpoint of the Ru2-Ru2′ bond,
entailing equidistant Ru1-Ru2 and Ru1-Ru2′ bond
lengths. Not only does the presence of the phosphine
on only one side of the sulfur-bridged Ru-Ru bond
destroy this symmetry, but it also renders all of the
metal-metal bonds slightly unequal. Specifically, the
non-sulfur-bridged bonds are shown to shorten, the
shortest of which (Ru2-Ru3, 2.7642(10) Å) involves the
Ru atom associated with the PPh3 ligand. The Ru1-
Ru2 bond elongates (Ru1-Ru2, 2.8592(11) Å in 3 vs
2.8421(5) Å in 1). At the hydride ligand, the asymmetry
manifests itself in a noticeably shorter bond between
the hydride and the phosphine bonded Ru (Ru(1-H(1),
1.97(6) Å; Ru(2)-H(1), 1.69(6) Å). The atom H1 is found
to fall 0.89(7) Å below the M3 plane. Stated alterna-
tively, the Ru1-H-Ru2 plane forms an angle of 51°
from thermolysis reactions of 4. The product could be
separated from the reaction mixture as a red band on
Al2O3 TLC plates. Refluxing solutions of the reactants
in a lower boiling solvent (i.e., THF) over extended
periods of time resulted in formation of 5 but only in
very small quantities; the major product was the PPh3-
1
substituted cluster 3. According to infrared and H and
31P NMR spectroscopic data (see Experimental Section),
cluster 5 differs structurally from clusters 3 and 4. The
IR spectrum in the carbonyl region is simple, showing
only four strong bands and indicating extensive substi-
tution at the metal framework. The nature of these
substitutions becomes more apparent upon considering
1
with the M3 plane. As implied by the H NMR spec-
trum, the binding site of the PPh3 is an equatorial
position on one of the sulfur-bonded Ru atoms, cis to
the bridging hydride.
1
the NMR spectra. In the H NMR spectrum, a bridging
hydride group is no longer observed and the number
and nature of the phenyl groups has changed. The
phenyl region is more complex than that observed for
1. In addition, the characteristic IR stretches of the
diphenylthioureato ligand are absent. The presence of
(6) (a) Cabeza, J . A.; Franco, R. J .; Llamazares, A.; Riera, V.; Pe´rez-
Carreno, E.; Van der Maelen, J . F. Organometallics 1994, 13, 55. (b)
Andreu, P. L.; Cabeza, J . A.; Cuya´s, J . L.; Riera, V. J . Organomet.
Chem. 1992, 427, 363. (c) Andreu, P. L.; Cabeza, J . A.; Pellinghelli,
A.; Riera, V.; Tiripicchio, A. Inorg. Chem. 1991, 30, 4611. (d) Andreu,
P. L.; Cabeza, J . A.; Riera, V.; Bois, C.; J eannin, Y. J . Chem. Soc.,
Dalton Trans. 1990, 3347.
(7) Andreu, P. L.; Cabeza, J . A.; Ferna´ndez-Colinas, J . M.; Riera,
V. J . Chem. Soc., Dalton Trans. 1990, 2927.
(8) Andreu, P. L.; Cabeza, J . A.; Pellinghelli, A.; Riera, V.; Tiripic-
chio, A. Inorg. Chem. 1991, 30, 4611.
(9) Carty, A. J .; MacLaughlin, S. A.; Nucciarone, D. In Phosphorous-
31 NMR Spectroscopy in Stereochemical Analysis; Berkade, J . G., Quin,
L. D., Eds.; VCH Publishers Inc.: New York, 1987; Chapter 16.

Trinuclear Cluster (µ2-H)Ru3(CO)9(µ3,η2-SCNHPhNPh)
Organometallics, Vol. 15, No. 2, 1996 707
Ta ble 1. Cr ysta llogr a p h ic Da ta for 3, 5, a n d 6a
compound
3
5
6
mol formula
MW
Z
C
39H26N2O8PRu3S
C42H30O6P2Ru3S‚CH2Cl2
C46H36N2O7P2Ru3S2(CH2Cl2)2‚H2O
1313.85
4
1016.88
2
1112.8
4
cryst dimens/mm
cryst color/habit
cryst syst
space group
a/Å
0.34 × 0.27 × 0.23
orange/blocks
triclinic
P1h
10.014(2)
14.449(4)
14.573(4)
100.38(2)
98.70(2)
107.20(2)
1933.8(8)
1.746
2.56
193(1)
2003.75
6781
5278
0.68 × 0.53 × 0.42
black/blocks
monoclinic
P21/n
10.824(1)
19.193(5)
20.953(2)
90
97.44(1)
90
4316.2(13)
1.712
1.329
293(1)
2200
7595
7056
3/50
semiemp/ψ scans
0.2756/0.1875
0.99 × 0.65 × 0.61
orange-red/blocks
monclinic
P21/n
17.667(7)
17.681(5)
18.049(4)
90
108.06(2)
90
5360(3)
1.628
1.184
203(1)
2616
9410
5111
3/55
semiemp/ψ scans
0.1715/0.1176
b/Å
c/ Å
R/deg
â/deg
γ/deg
V/Å3
Dc/g cm-3
µ(Mo KR)/mm-1
T of data collctn (K)
F(000)
no. of unique data
no. of. data used [Fo > 2.5σ(Fo)]
2θmin/2θmax(deg)
absorptn correctn
max/min transmission
instrumental error factor kb
R(R′)c (3)
3/50
empirical
0.5936/0.4826
0.0005
0.036(0.055)
R(>2σF2)/R1(all) (5, 6)d,e
wR2(>2σF2)/wR2(all)f
wa
0.0506(0.0726)
0.1263 (0.1402)
0.0835
0.0754(0.1526)
0.1666(0.2044)
0.0964
resid el-density diff features
0.70, -0.55
1.247, -0.884
1.678, -1.133
(max, min)/e Å-3
a
Details in common: data collected on a Stoe-Siemens AED 2 four-circle diffractometer; graphite-monochromated Mo KR radiation, λ
) 0.710 73 Å; scan mode ω-θ. Refinement was by full-matrix least squares with a weighting scheme of the form w-1 ) σ2(Fo) + k(Fo2).
b
c Data refinement using NRCVAX, R ) ∑||Fo| - |Fc||/∑|Fo|, R′ ) [∑w(|Fo| - |Fc|)2/∑w(|Fo|)2]1/2
.
Data refinement using SHELXL 93. e R
d
) ∑||Fo| - |Fc||/∑|Fo|. f wR2 ) [{∑[w(Fo - Fc2)2]/∑[w(Fo)4]]1/2, w-1 ) [σ2(Fo2) + (waP)2], P ) (Fo + 2Fc2)/3.
2
2
1
a phosphido bridge is verified by the downfield shift of
one of the two peaks found in 31P NMR spectra of 5.9
The remaining peak occurs in the region normally
assigned to σ-bonded PPh3. On the basis of the coinci-
dence of spectral data with the crystallographically
characterized trinuclear cluster Ru3(CO)6(µ2-Ph)(µ2-
PPh2)2(µ3,η2-ampy),6a Cabeza identified a trinuclear
cluster containing two diphenylphosphido bridges, a
bridging aryl group, and a µ3,η2-methylbenzimidazole
ligand [Ru3(CO)6(µ2-C6H5)(µ2-PPh2)2(µ3,η2-mbim)]. The
agreement of the νCO region of IR spectra of 5 with this
mbim-based cluster at first suggested a second struc-
tural anologue to the ampy cluster; however, ambigu-
ities in the spectral and analytical data led to the
crystallographic characterization of this species, con-
firming the molecular formula Ru3(CO)7(µ2-η2-C6H4)(µ2-
PPh2)(PPh3)(µ3-S) (5).
Red, block crystals of 5 were found to crystallize in
the monoclinic space group P21/n with 4 molecules per
unit cell. One molecule of dichloromethane was associ-
ated with each molecule of 5. Relevant structural data
for 5 are summarized in Table 1. The crystallographi-
cally determined structure of 5 is presented in Figure
2. The atomic coordinates and relevant bond lengths
and angles for 5 are summarized in Tables 4 and 5,
respectively.
spheres of the Ru atoms. Consistent with the H NMR
spectrum, no hydride ligands are present in the struc-
ture of 5. Treating the µ3-S as a four-electron donor,
the µ2-PPh2 group as a three-electron donor, and the
aryl group as a three-electron donor, cluster 5 contains
a total of 48 electrons and is electronically saturated.
The ranges of metal-metal bond lengths are, on the
average, consistent with single bonds (5, average Ru-
Ru, 2.7706(7) Å); however, they have shortened relative
to those of 1. The Ru-S bonds show two typical Ru-S
bond lengths and one rather short Ru-S distance (Ru3-
S1, 2.365(2) Å). The bonding situation at the bridging
aryl group is somewhat unusual and is illustrated with
the associated bond lengths and atom orientations. The
C1 bridge itself is asymmetric (Ru1-C1, 2.130(6) Å;
Ru2-C1, 2.355(6) Å). The calculated distance between
the C2 atom of the bridging aryl group and Ru2
indicates a bonding interaction (Ru2-C2, 2.542(7) Å).
Since the presence of the phenyl hydrogen atom on C2
was verified in difference maps (and refined), the C2
atom, together with C1 most likely participate in a side-
on π-interaction with Ru2 while the Ru1-C1 represents
a σ-interaction. This σ,π-type interaction is also sug-
gested by the tilting of the plane of the aryl group
toward Ru2; the angle between the aryl plane and the
Ru3 plane is calculated as 67.97(14)°. Furthermore, the
double bonds of the C6H5 ligand are localized between
C3 and C4 (1.360(11) Å) and C5 and C6 (1.375(9) Å),
while the remaining C-C bond lengths indicate single-
bond character. The phosphido group bridges the Ru-
Ru vector in a relatively symmetric manner.
The molecular structure of 5 shows the original
trinuclear Ru framework where the only part of the
diphenylthioureato ligand that remains is a capping µ3-
S. Further bridging ligands include a diphenylphos-
phido group spanning the Ru2-Ru3 bond and an aryl
group wherein the C1 atom bridges the Ru1-Ru2
vector. One terminal PPh3 ligand is bound to Ru1 while
six terminal carbonyl groups complete the coordination
In assuming a µ2,η2-bridging mode, the aryl group of
5 is somewhat unique. The compounds of Cabeza et al.

708 Organometallics, Vol. 15, No. 2, 1996
Hoferkamp et al.
Ta ble 2. Atom ic Coor d in a tes a n d Biso (Å2) for
Refin ed Atom s of 3
x
y
z
Biso
Ru1
Ru2
Ru3
S1
0.22446(6)
0.21500(6)
0.14197(6)
0.03900(17)
0.30529(18)
-0.0735(6)
-0.2375(6)
-0.1022(7)
-0.2715(7)
-0.2525(9)
-0.2875(10)
-0.3400(10)
-0.3592(11)
-0.3256(9)
-0.1933(7)
-0.2585(8)
0.12269(4)
0.28756(4)
0.09788(4)
0.19799(13)
0.43234(14)
0.0771(4)
0.1111(4)
0.1211(5)
0.1742(6)
0.2725(7)
0.3315(7)
0.2941(9)
0.1962(10)
0.1343(7)
0.0157(5)
-0.0834(6)
-0.1427(6)
-0.1032(7)
-0.0043(7)
0.0558(6)
0.4867(5)
0.4317(6)
0.4772(7)
0.5742(6)
0.6295(6)
0.5856(6)
0.5398(5)
0.5610(6)
0.6449(6)
0.7088(6)
0.6883(6)
0.6051(6)
0.4172(5)
0.4148(6)
0.3972(7)
0.3814(7)
0.3816(6)
0.3993(6)
-0.0106(6)
-0.0902(5)
0.1574(6)
0.1698(5)
0.0797(6)
0.0523(5)
0.1293(6)
0.1477(5)
-0.0443(7)
-0.1269(5)
0.1297(6)
0.1492(5)
0.3170(6)
0.3324(5)
0.3380(6)
0.3701(5)
0.259(5)
0.16974(4)
0.30735(4)
0.33881(4)
0.16148(12) 1.91(8)
0.25007(13) 1.90(8)
1.94(3)
1.765(25)
1.96(3)
P1
N1
N2
C1
C2
C3
C4
C5
C6
C7
C8
C9
0.2691(4)
0.1594(4)
0.2022(5)
0.0991(5)
0.1377(6)
0.0804(8)
-0.0141(9)
-0.0536(7)
0.0035(6)
0.2995(5)
0.2520(6)
0.2818(7)
0.3602(7)
0.4086(6)
0.3772(5)
0.2782(5)
0.3043(6)
0.3315(6)
0.3342(6)
0.3080(6)
0.2817(5)
0.2984(5)
0.3959(5)
0.4372(5)
0.3829(6)
0.2859(6)
0.2440(5)
0.1208(5)
0.0624(5)
-0.0359(6)
-0.0767(6)
-0.0196(6)
0.0789(5)
0.1206(5)
0.0908(4)
0.0537(5)
-0.0154(4)
0.2006(5)
0.2164(4)
0.4629(6)
0.5388(4)
0.3210(6)
0.3091(5)
0.3915(5)
0.4256(4)
0.3715(5)
0.4074(4)
0.4212(5)
0.4927(4)
0.245(5)
2.0(3)
2.5(3)
1.8(3)
2.5(3)
3.9(4)
4.6(5)
5.2(6)
5.6(7)
3.8(5)
2.3(3)
3.0(4)
3.8(4)
4.2(5)
3.7(5)
2.7(4)
2.1(3)
2.9(4)
3.7(4)
3.3(4)
3.5(4)
2.8(4)
2.2(3)
2.6(4)
2.8(4)
3.3(4)
3.1(4)
2.7(4)
2.2(3)
2.8(4)
3.6(4)
4.0(5)
3.5(4)
2.7(4)
2.8(4)
4.1(3)
2.7(4)
4.5(3)
2.7(4)
3.8(3)
2.7(4)
4.3(3)
3.0(4)
5.4(4)
2.8(4)
4.0(3)
2.6(3)
4.3(3)
2.6(4)
4.3(3)
2.5(15
F igu r e 2. Molecular structure of 5.
C10 -0.3720(9)
C11 -0.4173(9)
C12 -0.3501(9)
C13 -0.2382(7)
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 3
C14
C15
C16
C17
C18
C19
C20
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
O32
C33
O33
C34
O34
C35
O35
C36
O36
C37
O37
C38
0.5015(7)
0.5874(8)
0.7368(8)
0.7997(8)
0.7154(8)
0.5684(8)
0.2544(7)
0.2522(7)
0.2261(8)
0.1991(8)
0.1998(8)
0.2267(8)
0.2564(7)
0.3543(8)
0.3091(9)
0.1681(10)
0.0692(8)
0.1134(8)
0.0975(8)
0.0229(6)
0.2776(8)
0.3116(6)
0.3812(8)
0.4766(6)
0.1009(8)
0.0853(6)
0.1012(8)
0.0815(8)
0.3379(8)
0.4562(6)
0.0800(8)
Bond Distances
Ru(1)-Ru(2)
Ru(1)-Ru(3)
Ru(1)-S(1)
Ru(1)-H(1)
Ru(2)-Ru(3)
Ru(2)-P(1)
Ru(2)-S(1)
Ru(2)-H(1)
Ru(3)-N(1)
2.8592(11)
2.7642(10)
2.4128(17)
1.97(6)
2.7614(11)
2.3726(19)
2.4138(20)
1.69(6)
Ru(3)-C(36)
P(1)-C(14)
P(1)-C(20)
P(1)-C(26)
S(1)-C(1)
N(1)-C(1)
N(1)-C(8)
N(2)-C(1)
N(2)-C(2)
1.933(9)
1.836(7)
1.830(7)
1.830(7)
1.775(6)
1.298(8)
1.448(8)
1.357(8)
1.451(9)
2.149(5)
Bond Angles
Ru(1)-Ru(2)-Ru(3)
Ru(1)-Ru(2)-P(1)
Ru(1)-Ru(3)-Ru(2)
Ru(1)-S(1)-Ru(2)
Ru(1)-S(1)-C(1)
58.89(3)
106.81(5)
62.32(3)
72.65(5)
Ru(3)-N(1)-C(1) 122.6(4)
Ru(3)-N(1)-C(8) 120.0(4)
S(1)-Ru(2)-P(1)
S(1)-C(1)-N(1)
94.16(7)
120.0(5)
116.6(5)
123.3(6)
117.4(5)
123.8(6)
106.16(22) S(1)-C(1)-N(2)
Ru(1)-H(1)-Ru(2) 102(3)
N(1)-C(1)-N(2)
C(1)-N(1)-C(8)
Ru(2)-Ru(1)-Ru(3)
Ru(2)-P(1)-C(14)
Ru(2)-P(1)-C(20)
Ru(2)-P(1)-C(26)
Ru(2)-S(1)-C(1)
58.79(3)
114.51(23) C(1)-N(2)-C(2)
116.03(23) C(14)-P(1)-C(20) 101.5(3)
116.08(23) C(14)-P(1)-C(26) 103.7(3)
103.00(22) C(20)-P(1)-C(26) 103.2(3)
σ,π-interaction exhibited in cluster 5 represents the first
example of an aryl ligand employing combined bridging
and side-on π-coordination in a ruthenium cluster.
The formation of 5 from thermolysis reactions of 1 in
the presence of PPh3 has interesting implications. The
thermolysis of 1 in the absence of PPh3 leads to an
entirely different group of products.13 This, in conjunc-
tion with formation of 5 in thermolysis reactions of 4,
suggests the intermediacy of a PPh3-substituted deriva-
tive. The degradation of PPh3 groups to give phosphido
bridges is not unfounded, and their formation in the
presence of a bridging hydride to provide for elimination
of benzene also occurs.14 The mechanism for the forma-
tion of the η2-aryl ligand in 5 has not been firmly
established but presumably results from orthometala-
tion of one of the PPh3 groups of 4 formed in situ which,
rather than eliminating benzene, forms the bridging
aryl group. Elimination of a diaminocarbene fragment
from the diphenylthioureato ligand may be responsible
for the absence of the hydride, implying priority to the
P-C bond activation.
O38 -0.0084(6)
C39
O39
H1
0.3545(8)
0.4361(6)
0.333(7)
mentioned above6a are the first examples of symmetrical
bridging phenyl groups across Ru-Ru bonds. Other
platinum group clusters with η1-phenyl groups are also
known.10 As for a σ,π-interaction of a vinyl ligand, the
ampy bridged cluster of Cabeza has been shown to add
diphenylacetylene in such a way that the resulting
alkenyl ligand employs a σ,π -interaction in bridging a
Ru-Ru bond, similar to the situation for 5.11 With
respect to phenyl rings serving as ligands, this type of
interaction has been observed only once in a trinuclear
cluster consisting of Mo, Rh, and Pt.12 However, the
(10) (a) Bradford, C. W.; Nyholm, R. S. J . Chem. Soc., Dalton Trans.
1973, 529. (b) Bender, R.; Braunstein, P.; Tiripicchio, A.; Tiripicchio-
Camellini, M. Angew. Chem. Int. Ed. 1985, 24, 861. (c) Garding, M.
M.; Nicholls, B. S.; Smith, A. K., J . Chem. Soc., Dalton Trans. 1983,
1479.
(11) Briard, P.; Cabeza, J . A.; Llamazares, A.; Ouahab, L.; Riera,
V. Organometallics 1993, 12, 1006.
(12) Farrugia, L. J .; Miles, A. D.; Stone, F. G. A. J . Chem. Soc.,
Dalton Trans. 1984, 2415.
(13) Bodensieck, U.; Hoferkamp, L.; Stoeckli-Evans, H.; Su¨ss-Fink,
G. J . Chem. Soc., Dalton Trans. 1993, 127
(14) Lugan, N.; Ibers, J . A.; Bonnet, J .-J . J . Am. Chem. Soc. 1985,
107, 4484.

Trinuclear Cluster (µ2-H)Ru3(CO)9(µ3,η2-SCNHPhNPh)
Organometallics, Vol. 15, No. 2, 1996 709
Ta ble 4. Atom ic Coor d in a tes(×104) a n d Ueq (×103)
Ta ble 5. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 5
(Å2) for Refin ed Atom s of 5
x
y
z
U(eq)
Bond Distances
Ru(1)-Ru(2)
Ru(1)-Ru(3)
Ru(1)-P(1)
Ru(1)-S(1)
Ru(1)-C(1)
Ru(2)-Ru(3)
Ru(2)-P(2)
Ru(2)-S(1)
Ru(2)-C(1)
Ru(2)-C(2)
Ru(3)-P(2)
Ru(3)-S(1)
2.7738(8)
2.7032(7)
2.381(2)
2.441(2)
2.130(6)
2.8348(7)
2.292(2)
2.413(2)
2.355(6)
2.542(7)
2.243(2)
2.365(2)
P(1)-C(7)
P(1)-C(13)
P(1)-C(19)
P(2)-C(25)
P(2)-C(31)
C(1)-C(2)
C(1)-C(6)
C(2)-C(3)
C(3)-C(4)
C(4)-C(5)
C(5)-C(6)
1.825(7)
1.836(6)
1.838(6)
1.820(7)
1.818(7)
1.415(9)
1.440(9)
1.414(10)
1.360(11)
1.398(11)
1.375(9)
Ru(1)
Ru(2)
Ru(3)
S(1)
P(1)
P(2)
C(1)
C(2)
C(3)
C(4)
1243(1)
2499(1)
-137(1)
1131(2)
1547(1)
1059(2)
3218(6)
3849(6)
5163(7)
5862(7)
5288(6)
4011(6)
1538(6)
1071(8)
1000(9)
1366(8)
1840(7)
1930(7)
341(6)
-376(7)
-1339(8)
-1589(7)
-878(7)
61(6)
3046(6)
3225(6)
4392(8)
5423(7)
5252(6)
4086(6)
911(6)
1654(1)
2488(1)
2400(1)
2923(1)
1267(1)
2920(1)
1742(3)
2359(4)
2416(4)
1860(5)
1232(4)
1175(4)
1905(4)
2572(4)
3025(4)
2845(5)
2194(5)
1726(4)
647(3)
758(4)
301(5)
-265(4)
-381(4)
70(3)
827(3)
123(4)
-175(4)
243(4)
4450(1)
5403(1)
5193(1)
4489(1)
3402(1)
6011(1)
4638(3)
4504(3)
4613(4)
4843(4)
4972(3)
4885(3)
2756(3)
2816(4)
2309(4)
1738(4)
1668(4)
2174(3)
3068(3)
2476(3)
2257(4)
2616(4)
3199(4)
3424(3)
3370(3)
3485(3)
3527(4)
3453(4)
3335(3)
3299(3)
6095(3)
6601(4)
6648(5)
6187(5)
5688(5)
5635(4)
6836(3)
7241(3)
7852(4)
8089(4)
7712(4)
7084(4)
4213(3)
4013(3)
4852(3)
5134(3)
5683(3)
5869(3)
6044(3)
6410(3)
5121(3)
5065(3)
5644(3)
5875(3)
4309(5)
3365(7)
4030(12)
32(1)
33(1)
36(1)
38(1)
34(1)
37(1)
40(2)
41(2)
56(2)
63(2)
53(2)
48(2)
40(2)
57(2)
73(3)
69(2)
62(2)
52(2)
39(2)
55(2)
72(2)
62(2)
58(2)
48(2)
36(1)
46(2)
59(2)
60(2)
50(2)
43(2)
44(2)
64(2)
94(3)
88(3)
77(3)
58(2)
45(2)
59(2)
82(3)
93(4)
79(3)
59(2)
45(2)
71(2)
44(2)
69(2)
44(2)
73(2)
44(2)
60(1)
46(2)
76(2)
47(2)
70(2)
476(9)
410(7)
366(24)
C(5)
C(6)
C(7)
C(8)
Bond Angles
Ru(1)-Ru(2)-Ru(3)
Ru(1)-Ru(3)-Ru(2)
Ru(1)-C(1)-Ru(2)
Ru(2)-S(1)-Ru(1)
Ru(2)-C(2)-H(2)
Ru(3)-Ru(1)-Ru(2)
Ru(3)-P(2)-Ru(2)
Ru(3)-S(1)-Ru(1)
Ru(3)-S(1)-Ru(2)
P(1)-Ru(1)-Ru(2)
P(1)-Ru(1)-Ru(3)
P(1)-Ru(1)-S(1)
P(2)-Ru(2)-S(1)
57.62(2) P(2)-Ru(2)-C(1)
155.0(2)
160.9(2)
C(9)
60.06(2) P(2)-Ru(2)-C(2)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(101)
O(101)
C(102)
O(102)
C(201)
O(201)
C(202)
O(202)
C(301)
O(301)
C(302)
O(302)
Cl(1)
76.2(2)
C(1)-Ru(1)-Ru(3) 117.9(2)
69.70(5) C(1)-Ru(1)-S(1)
98(4) C(1)-Ru(2)-C(2)
88.1(2)
33.3(2)
66.1(3)
122(4)
122.0(5)
80.6(4)
115.0(6)
122.3(7)
113(4)
62.32(2) C(1)-C(2)-Ru(2)
77.37(5) C(1)-C(2)-H(2)
68.43(5) C(2)-C(1)-Ru(1)
72.77(5) C(2)-C(1)-Ru(2)
136.93(4) C(2)-C(1)-C(6)
148.12(4) C(3)-C(2)-C(1)
110.82(6) C(3)-C(2)-H(2)
85.66(6) C(31)-P(2)-C(25) 103.1(3)
tional phosphine diphenylphosphinoethane (dppe) to
give the trinuclear cluster (µ2-H)Ru3(CO)7(Ph2PCH2CH2-
PPh2)(µ3,η2-SCNHPhNPh) (6) in high yield (80%). Clus-
942(4)
1237(4)
3859(3)
4133(4)
4850(5)
5299(5)
5021(4)
4312(4)
2611(3)
2663(4)
2399(5)
2099(5)
2054(5)
2304(4)
1525(4)
1371(3)
776(4)
362(8)
193(11)
572(10)
1083(9)
1261(7)
1148(7)
2270(8)
2399(10)
1429(13)
290(11)
164(8)
-554(6)
-1538(4)
1336(6)
1367(5)
3670(6)
4357(5)
3090(6)
3397(5)
-1461(6)
-2252(5)
-918(6)
-1444(5)
4875(17)
3065(8)
3579(26)
263(3)
3200(4)
3622(3)
1820(4)
1403(3)
3034(4)
3429(3)
1711(4)
1287(3)
4412(6)
4406(6)
4959(12)
ter 6 could only be isolated by crystallization from the
reaction solution; attempts to purify the compound with
preparative TLC resulted in almost complete decompo-
sition. The IR spectrum of 6 compares well with that
of the disubstituted PPh3 cluster 4, and the presence of
only a single peak in 31P NMR spectra indicates a
symmetrically bound dppe moiety. Combined, these
spectroscopic features suggest substitution of a single
carbonyl group on each of two adjacent Ru atoms. The
most likely binding site of the dppe is bridging the two
sulfur-bound Ru atoms, a condition that would allow
for retention of the mirror-plane symmetry of 1. The
triplet displayed by the bridging hydride in the 1H NMR
spectrum confirms this placement, and the small cou-
pling constant of that multiplet further implies a
hydride cis to the two phosphorus atoms. An intact
diphenylthioureato ligand is inferred from its charac-
teristic bands in the IR spectra. The doublet observed
Cl(2)
C(1S)
Both the ampy and mbim PPh3 clusters of Cabeza
underwent thermal activation of P-C bonds to form η1-
phenyl-bridged species. The disubstituted ampy clus-
ters required high temperatures and the presence of H2
to initiate P-C bond cleavage while for the mbim
clusters, refluxing a THF solution of the unsubstituted
species in the presence of 2 equiv of PPh3 gave a product
analogous to the ampy-aryl cluster. Cluster 1 shows
reactivity toward P-C bond activation intermediate
between that of the ampy and the mbim clusters in that
thermal activation is necessary but the presence of H2
is not required.
1
in the alkyl region of the H NMR spectrum of 6, which
originates from the ethylene grouping of the dppe
ligand, suggests either perfectly equivalent CH2 groups
or a certain degree of fluxionality. In contrast, a triplet
is observed in 1H NMR spectra of the unligated dppe.
Because no analogous structure was found in the
literature, a single-crystal X-ray structural analysis of
Rea ction s of (µ2-H)Ru 3(CO)9(µ3,η2-SCNHP h NP h )
(1) w ith Dip h en ylp h osp h in oeth a n e (d p p e). Com-
plex 1 reacts almost instantaneously with the difunc-

710 Organometallics, Vol. 15, No. 2, 1996
Hoferkamp et al.
Ta ble 6. Atom ic Coor d in a tes (×104) a n d Ueq (×103)
(Å2) for Refin ed Atom s of 6
x
y
z
U(eq)
Ru(1)
Ru(2)
Ru(3)
P(1)
P(2)
S(1)
N(1)
N(2)
C(1)
C(2)
C(3)
C(4)
C(5)
C(7)
C(6)
C(8)
C(9)
-374(1)
900(1)
895(1)
3762(1)
3309(1)
2923(1)
4443(2)
3880(2)
4544(2)
3979(5)
5272(5)
4583(7)
3985(6)
4079(8)
4026(8)
3890(8)
3878(6)
3807(7)
5971(6)
6585(7)
7264(7)
7355(7)
6732(8)
6035(8)
4308(7)
4610(7)
5475(7)
5882(7)
6674(7)
7040(7)
6658(7)
5876(7)
4175(6)
3500(9)
3290(11)
3683(9)
4313(9)
4553(9)
5170(7)
4405(7)
5542(8)
5151(9)
4356(10)
3982(8)
3303(6)
3493(7)
3094(7)
2500(8)
2292(8)
2709(7)
4249(7)
4515(5)
2994(7)
2546(6)
3351(7)
3420(6)
2305(7)
1690(5)
2413(8)
2094(6)
2863(7)
2762(6)
2036(8)
1494(5)
6278(15)
6155(3)
6553(7)
4805(11)
4302(4)
4807(4)
4601(22)
3358(52)
3066(1)
2514(1)
3994(1)
2016(2)
1277(2)
3014(2)
4405(5)
4249(6)
3990(6)
5153(6)
5168(7)
5866(8)
6546(8)
5836(7)
6528(7)
3828(7)
4100(7)
3743(8)
3114(8)
2831(8)
3191(7)
1073(6)
1082(6)
2057(6)
2699(7)
2731(7)
2120(8)
1474(8)
1449(7)
1805(6)
1421(9)
1294(9)
1540(8)
1967(11)
2089(9)
1158(7)
1129(6)
1070(8)
973(8)
30(1)
31(1)
32(1)
32(1)
31(1)
31(1)
36(2)
41(3)
35(3)
31(3)
47(3)
57(4)
58(4)
39(3)
54(4)
36(3)
46(3)
52(4)
54(4)
54(4)
50(4)
41(3)
39(3)
33(3)
42(3)
42(3)
46(3)
53(4)
42(3)
34(3)
69(5)
80(5)
61(4)
77(5)
73(5)
49(4)
36(3)
62(4)
59(4)
61(4)
48(3)
29(3)
38(3)
47(3)
48(3)
54(4)
43(3)
36(3)
57(3)
43(3)
64(3)
45(3)
62(3)
48(3)
79(4)
47(3)
61(3)
40(3)
58(3)
48(3)
69(3)
144(9)
107(2)
219(5)
118(8)
138(2)
130(2)
366(27)
33(29)
-1231(2)
574(2)
729(2)
1519(6)
1690(6)
1391(7)
2151(7)
2927(7)
3535(8)
3357(9)
1974(8)
2592(9)
1611(7)
1316(8)
1274(8)
1548(9)
1839(8)
1876(8)
-1041(7)
-197(7)
-1280(7)
-822(8)
-895(8)
-1430(8)
-1888(9)
-1807(7)
-2274(7)
-2558(10)
-3337(10)
-3845(9)
-3559(9)
-2779(9)
1460(9)
1400(7)
2110(10)
2725(9)
2688(9)
2025(7)
212(7)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(29)
C(28)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(37)
C(38)
C(39)
C(40)
O(40)
C(41)
O(41)
C(42)
O(42)
C(43)
O(43)
C(44)
O(44)
C(45)
O(45)
C(46)
O(46)
C(1S)
Cl(1S)
Cl(2S)
C(2S)
Cl(3S)
Cl(4S)
O(1W)
H(1RU)
F igu r e 3. Molecular structure of 6.
6 was undertaken. Crystals of 6 are monoclinic and
belong to the space group P21/n with four molecules per
unit cell. Other relevant crystal data are collected in
Table 1. The molecular structure of 6 is presented in
Figure 3, and atomic coordinates and selected bond
distances and angles are presented in Tables 6 and 7,
respectively.
Figure 3 shows a trinuclear cluster similar to 1 except
that substitution of two carbonyl ligands on adjacent
Ru atoms has occurred and those coordination sites
taken up in σ-bonds to the two P atoms of dppe. The
Ru-P bond lengths observed in 6 are typical for this
ligand in Ru clusters. As suggested by the spectroscopic
data, the dppe ligand is found spanning the S-bridged
edge of the trinuclear cluster in a position cis to the
bridging hydride and the bridging sulfur. In contrast
to the changes in Ru-Ru bond lengths brought on by
substitution with a single PPh3, the Ru-Ru bonds of
the cluster are little changed by the presence of the
dppe. The three Ru atoms and the two P atoms of the
dppe ligand form a pentagonal base which is planar to
within 0.053(1) Å. The bridging hydride (H1Ru) as-
sumes a position 0.75(7) Å below the M3P2 plane while
C14 and C15 are positioned respectively, 0.53(1) Å below
and 0.49(1) Å above. Within the standard deviations
of the determined bond lengths and angles, no changes
for the diphenylthioureato ligand are observed.
A pseudomirror plane containing Ru3, N1, C1, and
S1 bisects the Ru1-Ru2 and C14-C15 bonds. In the
solid state, the dppe ligand distorts this symmetry
element through the inequivalency of the methylene
groups. However, the presence of only a doublet in the
1H NMR spectrum indicates that these groups must be
considerably fluxional in solution. No symmetry re-
straints are presented by the phenyl groups of the
ligated dppe. Those groups are forced to adopt a single
orientation with respect to the metal cluster, which
renders them equivalent.
938(8)
1022(8)
408(6)
-302(6)
-972(7)
-971(7)
-294(8)
387(7)
354(7)
-4(8)
-490(8)
-666(8)
-277(8)
-593(7)
-727(6)
-1091(8)
-1556(6)
1992(9)
2696(5)
931(8)
3894(6)
4427(5)
3069(7)
3073(6)
2872(7)
3111(5)
2183(8)
1962(6)
4417(7)
4678(5)
4781(7)
5228(5)
3517(7)
3251(5)
5691(13)
5948(3)
4811(4)
2915(10)
2547(4)
3934(4)
-49(16)
2259(28)
957(7)
1884(8)
2482(6)
408(7)
61(5)
371(8)
75(7)
3627(14)
2810(3)
3540(4)
-5997(14)
-5368(4)
-5675(4)
-5541(19)
-127(18)
Two molecules of CH2Cl2 and one molecule of H2O
were found to cocrystallize in the unit cell. The CH2-
Cl2 originates from the crystallization solvent (CH2Cl2/
hexanes), while the source of the molecule of H2O is not
sure.
The dppe ligand typically takes on a bridging mode
in cluster complexes and in doing so lends a degree of
stability to the resulting cluster molecule.15 This was
the case with the trinuclear cluster (µ2-H)Ru3(CO)7(Ph2-
PCH2PPh2)(µ3,η2-ampy) prepared, but not structurally
(15) Braunstein, P. In Perspectives in Coordination Chemistry;
Williams, A. F., Floriani, C., Merbach, A. E., Eds.; VCH Publishers
Inc.: New York, 1992; p 78.

Trinuclear Cluster (µ2-H)Ru3(CO)9(µ3,η2-SCNHPhNPh)
Organometallics, Vol. 15, No. 2, 1996 711
Ta ble 7. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 6
of solvents was carried out under an N2 atmosphere; the inert
atmosphere over the solvent was maintained thereafter. The
cluster (µ2-H)Ru3(CO)9- (µ3,η2-SCNHPhNPh) (1) was prepared
according to a previously published procedure.1a Other chemi-
cals (N,N′-diphenylthiourea (Fluka, 98%), triphenylphosphine
(Merck, 98%), 1,2-bis(diphenylphosphino)ethane (Aldrich, 97%))
were purchased from the appropriate vendors and used as
received. Infrared spectra were obtained using a Perkin-Elmer
1720 X spectrometer; 1H, 13C, and 31P NMR spectra were
acquired with either a Bruker AMX 400 or a Varian Gemini
200 BB spectrometer and the measurement temperature
indicated. Elemental analyses were performed by the Mik-
roelementaranalytisches Laboratorium ETH, Zurich, Switzer-
land. FAB mass spectra were measured by Professor T. A.
J enny of the University of Fribourg, Fribourg, Switzerland,
using 3-nitrobenzyl alcohol (NBA) as the matrix.
X-ray structural data were collected on a Stoe-Siemens AED
2 four-circle diffractometer using graphite-monochromatized
Mo KR radiation (λ ) 0.710 73 Å). Low-temperature measure-
ments were carried out using controlled-temperature nitrogen
gas flow. Crystal structure data were solved with SHELXS-
8618 and refined with SHELXL-9319 or the NRCVAX20 program
packages of the VAX-Cluster of the De´partment de Calcul of
the Universite´ de Neuchaˆtel. Illustrations showing thermal
motion ellipsoids were drawn using either the PLATON21 or
ZORTEP22 program. Additional data for structures have been
deposited with the Cambridge Crystallographic Data Centre,
Union Road, GB-Cambridge CB2 1EW, U.K.
Bond Lengths
Ru(1)-Ru(2)
Ru(1)-Ru(3)
Ru(1)-P(1)
Ru(1)-S(1)
Ru(1)-H(1RU)
Ru(2)-Ru(3)
Ru(2)-P(2)
Ru(2)-S(1)
2.843(2)
2.776(2)
2.357(3)
2.413(3)
1.79(3)
2.7601(13)
2.353(3)
2.417(3)
1.73(3)
P(1)-C(16)
P(1)-C(22)
P(2)-C(15)
P(2)-C(28)
P(2)-C(34)
S(1)-C(1)
N(1)-C(1)
N(1)-C(2)
N(2)-C(1)
N(2)-C(8)
C(14)-C(15)
1.828(12)
1.826(12)
1.830(12)
1.817(12)
1.812(11)
1.788(12)
1.284(14)
1.460(14)
1.353(14)
1.435(14)
1.58(2)
Ru(2)-H(1RU)
Ru(3)-N(1)
P(1)-C(14)
2.178(9)
1.848(10)
Bond Angles
Ru(1)-S(1)-Ru(2)
Ru(2)-Ru(3)-Ru(1)
Ru(3)-Ru(1)-Ru(2)
Ru(3)-Ru(2)-Ru(1)
P(1)-Ru(1)-S(1)
P(2)-Ru(2)-S(1)
N(1)-C(1)-S(1)
N(1)-C(1)-N(2)
N(2)-C(1)-S(1)
C(1)-S(1)-Ru(1)
C(1)-S(1)-Ru(2)
C(1)-N(1)-Ru(3)
C(1)-N(1)-C(2)
C(1)-N(2)-C(8)
C(2)-N(1)-Ru(3)
72.13(9)
61.80(4)
58.82(4)
59.38(4)
C(14)-P(1)-Ru(1) 114.8(4)
C(14)-C(15)-P(2) 114.1(8)
C(15)-P(2)-Ru(2) 115.7(4)
C(15)-C(14)-P(1) 112.8(8)
90.08(11) C(16)-P(1)-Ru(1) 120.3(4)
86.88(10) C(16)-P(1)-C(14) 101.0(5)
119.1(9)
124.7(11)
116.2(9)
105.9(4)
106.5(4)
122.4(8)
118.6(10)
129.0(10)
118.8(7)
C(22)-P(1)-C(14) 103.5(5)
C(22)-P(1)-Ru(1) 113.0(4)
C(22)-P(1)-C(16) 102.1(5)
C(28)-P(2)-Ru(2) 112.8(4)
C(28)-P(2)-C(15) 101.3(5)
C(34)-P(2)-Ru(2) 119.7(4)
C(34)-P(2)-C(15) 100.9(5)
C(34)-P(2)-C(28) 104.2(5)
Syn th esis of Ru (CO)2(η2-SCNHP h NP h )2 (2) (a ) Dir ect
Syn th esis. A solution of Ru3(CO)12 (40.5 mg, 0.0633 mmol)
and (PhNH)2CS (86.4 mg, 0.39 mmol) in THF (20 mL) was
stirred at room temperature for 7 days. The solvent was
removed and the residue redissolved in CH2Cl2 and chromato-
graphed on Al2O3 TLC plates in 1:1 CH2Cl2/cyclohexane,
yielding in order of elution, 2 (26.6 mg, 23%) as a colorless
band (detected with a UV lamp) and 1 (5.6 mg, 11.3%) as an
orange band.
characterized, by Cabeza and co-workers.16 Contrary
to thermolysis of the disubstituted PPh3 analogue (recall
thermolysis under H2 pressure produced P-C bond
cleavage), exposure of the dppe/ampy cluster to elevated
temperatures had no effect. The stabilizing effect of the
dppe ligand is apparent. The behavior of cluster 6
under thermolytic conditions, however, does not suggest
a significant stabilization effect from the dppe ligand.
Refluxing a cyclohexane solution of 6 over a period of 1
h resulted in formation of at least five different carbonyl
clusters.
(b) Rea ction of 1 w ith (P h NH)2CS. A solution of 1 (36.2
mg, 0.046 mmol) and (PhNH)2CS (13.2 mg, 0.058 mmol) in
THF (20 mL) was stirred at room temperature for 4 days. After
the solvent was removed, 2 was isolated as a colorless band
by TLC (Al2O3, 1:1 CH2Cl2/cyclohexane) (13.1 mg, 15.4%): IR
Con clu sion s
(c-hex, 298 K) νCO (cm-1) 2039 s, 1973 s; IR (KBr) νNH (cm-1
)
3360 m, νNCN (cm-1) 1549 m; 1H NMR (CDCl3, 298 K, 400 MHz)
δ (ppm) 8.6 (s, br, 1H), 7.5-7.0 (m, 10H); FAB-MS (NBA) M+
) 612. Anal. Calcd for C28H22N4O2RuS2‚0.25CH2Cl2 (632.9):
C, 53.6; H, 3.58; N, 8.85. Found: C, 53.84; H, 3.58; N, 8.90.
Syn th esis of (µ2-H)Ru 3(CO)8(P P h 3)(µ3,η2-SCNHP h NP h )
(3). A solution of 1 (78.4 mg, 0.100 mmol) and PPh3 (27.6 mg,
0.105 mmol) in THF (20 mL) was stirred at room temperature
for 24 h. The solvent was removed and the residue dissolved
in CH2Cl2 and chromatographed on TLC plates (Al2O3, CH2-
Cl2/cyclohexane 30:70). Two major bands eluted. The first
band contained compound 4 (trace). The second band was
primarily compound 3 (69.9 mg, 69%) slightly contaminated
with 4. Orange-block crystals of 3 were obtained from CH2-
The added structural stability, originally perceived as
possible with the face-capping diphenylthioureato ligand,
has not always been shown to be the case. Exposure to
certain reagents has produced cluster fragmentation
even under extremely mild conditions, although it is
noted that the diphenylthioureato ligand itself remains
intact during this transformation. Other reagents, the
phosphine-based reagents specifically, result in substi-
tution of CO groups. While the phosphine-substituted
derivatives of 1 undergo ligand transformations upon
exposure to high temperatures, the original cluster
nuclearity is maintained.
Cl2 solutions at room temperature: IR (c-hex, 298 K) νCO (cm-1
)
2064 m, 2029 vs, 1998 ms, 1979 m, 1970 m, 1946 w,sh; IR
(KBr) νNH (cm-1) 3354 wm, νNCN (cm-1) 1572 m; 1H NMR
(CDCl3, 298 K, 200 MHz) δ (ppm) 7.50-6.90 (m, 25H), 6.08
(s, br, 1H), -12.52 (d, J ) 14 Hz, 1H); 31P NMR(CDCl3, 298
Exp er im en ta l Section
Manipulations were carried out using standard Schlenk
techniques under an N2 atmosphere. Thermolysis reactions
were performed in a high-pressure Schlenk tube able to
withstand 8 bar of internal pressure. TLC plates were
prepared by placing a uniform 0.5 mm layer of the appropriate
support (Al2O3 or SiO2; G or G/UV254, Macherey-Nagel) on 20
× 20 cm glass plates. Laboratory solvents were purified and
dried according to standard laboratory practices.17 Distillation
(18) Sheldrick, G. M. SHELXS-86, Program for Crystal Structure
Determination; University of Go¨ttingen, Go¨ttingen, Germany, 1986.
(19) Sheldrick, G. M. SHELXL-93, Program for Refinement of
Crystal Structure Data; University of Go¨ttingen, Go¨ttingen, Germany,
1993.
(20) Gabe, E. J .; Le Page, Y.; Charland, J .-P.; Lee, F. L. NRCVAX-
an Interactive Program System for Structure Analysis. J . Appl.
Crystallogr. 1989, 22, 384.
(16) Andreu, P. L.; Cabeza, J . A.; Ferna´ndez-Colinas, J . M.; Riera,
V. J . Chem. Soc., Dalton Trans. 1990, 2927.
(17) Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory
Chemicals, 3rd Ed.; Pergamon Press: Oxford, England, 1988.
(21) Spek, A. L. Acta Crystallogr. 1990, A46, C34.
(22) J ohnson, C. K. ORTEP, Oak Ridge National Laboratory, Oak
Ridge, TN, modified for PC (ZORTEP) by L. Zsolnai and H. Pritzkow,
University of Heidelberg, Heidelberg, Germany, 1994.

712 Organometallics, Vol. 15, No. 2, 1996
Hoferkamp et al.
K, 200 MHz) δ (ppm) 25.9 (s). Anal. Calcd for C39H27N2O8-
Ru3PS (1018): C, 46.0; H, 2.67; N, 2.75. Found: C, 45.7; H,
2.78; N, 2.46.
NMR (C6D6, 298 K, 200 MHz) δ (ppm) 7.8-6.2 (m); 31P NMR
(C6D6, 298 K, 200 MHz) δ (ppm) 215.0 (d, J ) 6.7 Hz), 40.6 (s,
br). Anal. Calcd for C43H29O7Ru3P2S‚0.5CH2Cl2 (1099.3): C,
47.5; H, 2.75. Found: C, 47.0; H, 2.94.
Syn t h esis of (µ2-H )R u 3(CO)7(P P h 3)2(µ3,η2-SCNH P h -
NP h ) (4). A solution of Ru3(CO)12 (50.0 mg, 0.064 mmol) and
PPh3 (35.2 mg, 0.134 mmol) in THF (20 mL) was stirred at
room temperature for 24 h. The solvent was removed and the
residue dissolved in CH2Cl2 and chromatographed on TLC
plates (Al2O3, 30:70 CH2Cl2/cyclohexane). Only one major band
migrated and consisted primarily of 4 (27mg, 34%) with traces
of 3: IR (c-hex, 298 K) νCO (cm-1) 2042 vs, 1996 s, 1986 w,
1970 s, 1936 m; IR (KBr) νNH (cm-1) 3366 wm, νNCN (cm-1) 1571
Syn th esis of (µ2-H)Ru 3(CO)7(µ2,η2-P h 2P CH2CH2P P h 2)-
(µ3,η2-SCNHP h NP h ) (6). A solution of 1 (30 mg, 0.038 mmol)
and (diphenylphosphino)ethane (16 mg, 0.040 mmol) in CH2-
Cl2 was stirred for 30 min. The solvent volume was reduced
to approximately 3 mL and an excess of hexanes layered on
top. After 24 h, the product could be collected as an orange
crystalline solid (35.3 mg, 82.5%): IR (c-hex, 298 K) νCO (cm-1
2043 s, 1997 vs, 1968 s, 1953 m, 1938 m; IR (KBr) νNH (cm-1
)
)
1
m; H NMR (CDCl3, 298 K, 200 MHz) δ (ppm) 7.60-6.70 (m,
3340 wm, νNCN (cm-1) 1573 m; 1H NMR (CDCl3, 298 K, 200
MHz) δ (ppm) 7.56-6.85 (m, 30H), 6.06 (s, 1H), 2.00 (d, J )
12.5 Hz, 4H), -12.94 (t, J ) 13.0 Hz, 1H); 31P NMR (CDCl3,
298 K, 200 MHz) δ (ppm) 18.53 (s). Anal. Calcd for C46H36N2O7-
Ru3P2S‚0.5CH2Cl2 (1168.5): C, 47.7; H, 3.19; N, 2.39. Found:
C, 47.7; H, 3.40; N, 1.91.
40H), 5.90 (s, br, 1H), -12.10 (t, J ) 9 Hz, 1H); 31P NMR
(CDCl3, 298 K, 200 MHz) δ (ppm) 29.0 (s). It was not possible
to obtain a pure sample of 4; a trace amount of 3 was
persistently present; therefore, no elemental analysis was
carried out on 4. However, FAB-mass spectral analysis (in
NBA) of a relatively pure sample shows an M+ peak at 1253
mass units.
Ack n ow led gm en t. We thank the Fonds National
Suisse pour la Recherche Scientifique for financial
support and the J ohnson Matthey Technology Centre
for a generous loan of ruthenium trichloride.
Syn th esis of Ru 3(CO)7(µ2,η2-C6H4)(µ2-P P h 2)(P P h 3)(µ3-S)
(5). A solution of 1 (48 mg, 0.061 mmol) and PPh3 (34 mg,
0.128 mmol) in toluene (20 mL) was refluxed for 2 h, forming
a deep red solution. The solvent was removed and the residue
dissolved in CH2Cl2 and chromatographed on TLC plates
(Al2O3, 30:70 CH2Cl2/cyclohexane). 5 was isolated from a major
red band located approximately half-way up the plate (20.5
mg, 32.0%). Alternatively, a refluxing, toluene solution of 4
produced 5 in approximately the same yield: IR (c-hex, 298
Su p p or tin g In for m a tion Ava ila ble: Tables of positional
and thermal parameters and complete tables of bond lengths
and angles and least-squares planes for 3, 5, and 6 (27 pages).
Ordering information available on any current masthead page.
1
K) νCO (cm-1) 2032 m, 2007 vs, 1982 s, 1952 s, 1939 vw; H
OM9507383