Synthesis of TiRu2 heterobimetallic and TiRuM (M = Rh, Ir, Pd, Pt) heterotrimetallic sulfido clusters from a hydrosulfido-bridged titanium-ruthenium complex

Article abstract of DOI:10.1021/ic0009324

Treatment of the hydrosulfido-bridged titanium-ruthenium heterobimetallic complex [Cp₂Ti(μ2-SH)₂RuCl (η⁵-C₅Me₅)] (1; Cp = η⁵-C₅H₅) with an excess of triethylamine followed by addition of [RuCl₂(PPh₃)₃] and [{(cod)M}₂-(μ₂-Cl)₂] (M = Rh, Ir; cod = 1,5-cyclooctadiene) led to the formation of the TiRu₂ and TiRuM mixed-metal sulfido clusters [(CpTi){(η⁵-C₅Me₅)Ru}{Ru (PPh₃)₂}(μ₃-S)₂ (μ₂-Cl)₂] (3) and [(CpTi){η⁵-C₅Me₅)Ru}{M(cod)}- (μ₃-S)₂(μ₂-Cl)] (M = Rh (4a), Ir (4b)), respectively. On the other hand, the reactions of 1 with [M(PPh₃)₄] (M = Pd, Pt) afforded the TiRuM trinuclear clusters [(CpTiCl){(η⁵-C₅Me₅)Ru}{M (PPh₃)₂}(μ₃-S)(μ₂-S) (μ₂-H)] (M = Pd (5a), Pt (5b)) with an unprecedented M₃(μ₃-S)(μ₂-S) core. The detailed structures of these triangular clusters 3-5 have been determined by X-ray crystallography. Crystal data: 3, triclinic, P1, a = 12.448(4) A, b = 12.773-(4) A, c = 17.270(4) A, α = 100. 16(2)°, β = 99.93(2)°, γ = 114.11(3)°, V = 2373(1) A³, Ζ = 2; 4a, triclinic, P1, a = 7.714(2) A, b = 11.598(3) A, c = 14.802(4) A, α = 80.46(2)°, β = 82.53(2)°, γ = 71.47(2)°, V = 1234.0(6) A³, Z = 2; 4b, triclinic, P1, a = 7.729(1) A, b = 11.577(2) A, c = 14.766(3) A, α = 80.14(1)°, β = 82.71(1)°, γ = 71.55(1)°, V = 1231.1(4) A³, Ζ = 2; 5a, monoclinic, P2₁/c, a = 11.259(4) A, b = 16.438(4) A, c = 26.092(5) A, β = 102.23(3)°, V = 4719(2) A³, Z = 4; 5b, monoclinic, P2₁/n, a = 11.369(2) A, b = 16.207-(3) A, c = 26.116(2) A, β = 102.29(1)°, V = 4701(1) A³, Ζ = 4.

Full text of DOI:10.1021/ic0009324

2034
Inorg. Chem. 2001, 40, 2034-2040
Synthesis of TiRu2 Heterobimetallic and TiRuM (M ) Rh, Ir, Pd, Pt) Heterotrimetallic
Sulfido Clusters from a Hydrosulfido-Bridged Titanium-Ruthenium Complex
Shigeki Kuwata,† Shin-ichiro Kabashima,† Nobuyuki Sugiyama,† Youichi Ishii,*,† and
Masanobu Hidai*,‡
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo,
Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, and Department of Materials Science and Technology,
Faculty of Industrial Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda,
Chiba 278-8510, Japan
ReceiVed August 14, 2000
Treatment of the hydrosulfido-bridged titanium-ruthenium heterobimetallic complex [Cp2Ti(µ2-SH)2RuCl(η5-
C5Me5)] (1; Cp ) η5-C5H5) with an excess of triethylamine followed by addition of [RuCl2(PPh3)3] and [{(cod)M}2-
(µ2-Cl)2] (M ) Rh, Ir; cod ) 1,5-cyclooctadiene) led to the formation of the TiRu2 and TiRuM mixed-metal
sulfido clusters [(CpTi){(η5-C5Me5)Ru}{Ru(PPh3)2}(µ3-S)2(µ2-Cl)2] (3) and [(CpTi){(η5-C5Me5)Ru}{M(cod)}-
(µ3-S)2(µ2-Cl)] (M ) Rh (4a), Ir (4b)), respectively. On the other hand, the reactions of 1 with [M(PPh3)4] (M )
Pd, Pt) afforded the TiRuM trinuclear clusters [(CpTiCl){(η5-C5Me5)Ru}{M(PPh3)2}(µ3-S)(µ2-S)(µ2-H)] (M )
Pd (5a), Pt (5b)) with an unprecedented M3(µ3-S)(µ2-S) core. The detailed structures of these triangular clusters
3-5 have been determined by X-ray crystallography. Crystal data: 3, triclinic, P1h, a ) 12.448(4) Å, b ) 12.773-
(4) Å, c ) 17.270(4) Å, R ) 100.16(2)°, â ) 99.93(2)°, γ ) 114.11(3)°, V ) 2373(1) Å3, Z ) 2; 4a, triclinic,
P1h, a ) 7.714(2) Å, b ) 11.598(3) Å, c ) 14.802(4) Å, R ) 80.46(2)°, â ) 82.53(2)°, γ ) 71.47(2)°, V )
1234.0(6) Å3, Z ) 2; 4b, triclinic, P1h, a ) 7.729(1) Å, b ) 11.577(2) Å, c ) 14.766(3) Å, R ) 80.14(1)°, â )
82.71(1)°, γ ) 71.55(1)°, V ) 1231.1(4) Å3, Z ) 2; 5a, monoclinic, P21/c, a ) 11.259(4) Å, b ) 16.438(4) Å,
c ) 26.092(5) Å, â ) 102.23(3)°, V ) 4719(2) Å3, Z ) 4; 5b, monoclinic, P21/n, a ) 11.369(2) Å, b ) 16.207-
(3) Å, c ) 26.116(2) Å, â ) 102.29(1)°, V ) 4701(1) Å3, Z ) 4.
Introduction
workers.7 A metal exchange reaction, i.e., replacement of one
metal vertex in a trinuclear cluster by its isolobal metal fragment,
gives an additional class of heterotrimetallic clusters.8-10
However, metals involved in these systematic studies have been
limited to group 6-11 metals.4
In the course of our extensive studies on sulfur-bridged
complexes of noble metals,11,12 our research group has estab-
lished the synthetic utility of the hydrosulfido-bridged homodi-
nuclear complexes [(η5-C5Me5)MCl(µ2-SH)2MCl(η5-C5Me5)]
(M ) Ru, Rh, Ir) for a variety of sulfido clusters.13-20 For
example, reactions of these hydrosulfido complexes with
Significant progress has been achieved in the methodology
of cluster synthesis during the last two decades. A substantial
part of this progress has been concerned with the development
of a rational strategy to control the structures and metal
composition of the clusters that are produced.1-3 Heterotrime-
tallic clusters with a triangular array of three distinct metal atoms
have been a major subject of systematic investigation to confirm
the efficiency of these rational approaches.4 Stone and co-
workers have demonstrated that stepwise accumulation of two
distinct metal fragments onto the mononuclear alkylidyne
complexes provides a general route to heterotrimetallic clusters
with a µ3-alkylidyne ligand.5,6 Substitution of an anionic ligand
in diphosphine-bridged heterodinuclear complexes by anionic
metal complexes has been developed by Braunstein and co-
(7) Braunstein, P.; de Me´ric de Bellefon, C.; Ries, M. Inorg. Chem. 1990,
29, 1181-1186 and references therein.
(8) Vahrenkamp, H. Comments Inorg. Chem. 1985, 4, 253-267.
(9) Vahrenkamp, H. AdV. Organomet. Chem. 1983, 22, 169-208.
(10) Waterman, S. M.; Lucas, N. T.; Humphrey, M. G. AdV. Organomet.
Chem. 2000, 46, 47-143.
(11) Hidai, M.; Mizobe, Y. In Transition Metal Sulfur Chemistry: Biologi-
cal and Industrial Significance; Stiefel, E. I., Matsumoto, K., Eds.;
American Chemical Society: Washington, DC, 1996; pp 310-323.
(12) Hidai, M.; Kuwata, S.; Mizobe, Y. Acc. Chem. Res. 2000, 33, 46-
52.
† The University of Tokyo.
‡ Science University of Tokyo.
(1) Adams, R. D. In ComprehensiVe Organometallic Chemistry II; Abel,
E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press: Oxford,
U.K., 1995; Vol. 10, pp 1-22.
(2) Adams, R. D. In The Chemistry of Metal Cluster Complexes; Shriver,
D. F., Kaesz, H. D., Adams, R. D., Eds.; VCH: New York, 1990; pp
121-170.
(3) Roberts, D. A.; Geoffroy, G. L. In ComprehensiVe Organometallic
Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W., Eds.;
Pergamon Press: Oxford, U.K., 1982; Vol. 6, pp 763-877.
(4) Farrugia, L. J. In ComprehensiVe Organometallic Chemistry II; Abel,
E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press: Oxford,
U.K., 1995; Vol. 10, pp 187-254.
(5) Stone, F. G. A. Pure Appl. Chem. 1986, 58, 529-536.
(6) Hill, A. F.; Marken, F.; Nasir, B. A.; Stone, F. G. A. J. Organomet.
Chem. 1989, 363, 311-323 and references therein.
(13) Kuwata, S.; Hidai, M. Coord. Chem. ReV. 2001, 213, 211-305.
(14) Hashizume, K.; Mizobe, Y.; Hidai, M. Organometallics 1996, 15,
3303-3309.
(15) Tang, Z.; Nomura, Y.; Ishii, Y.; Mizobe, Y.; Hidai, M. Organometallics
1997, 16, 151-154.
(16) Masui, D.; Ishii, Y.; Hidai, M. Chem. Lett. 1998, 717-718.
(17) Tang, Z.; Nomura, Y.; Kuwata, S.; Ishii, Y.; Mizobe, Y.; Hidai, M.
Inorg. Chem. 1998, 37, 4909-4920.
(18) Kochi, T.; Nomura, Y.; Tang, Z.; Ishii, Y.; Mizobe, Y.; Hidai, M. J.
Chem. Soc., Dalton Trans. 1999, 2575-2582.
(19) Kuwata, S.; Andou, M.; Hashizume, K.; Mizobe, Y.; Hidai, M.
Organometallics 1998, 17, 3429-3436.
10.1021/ic0009324 CCC: $20.00 © 2001 American Chemical Society
Published on Web 03/24/2001

Heterobimetallic and Heterotrimetallic Sulfido Clusters
Inorganic Chemistry, Vol. 40, No. 9, 2001 2035
crystals of 4a, which were collected by filtration and dried in vacuo
(128.6 mg, 40%). H NMR (C6D6): δ 6.48 (s, 5H, C5H5), 4.51, 4.35,
2.21, 2.06 (br s, 2H each, cod), 1.85 (s, 15H, C5Me5). The other
methylene resonances (4H) for the cod ligand are masked by the C5-
Me5 singlet. Anal. Calcd for C23H32ClRhRuS2Ti: C, 41.86; H, 4.89.
Found: C, 41.46; H, 5.01.
heterometallic compounds led to the formation of a series of
heterobimetallic sulfido clusters with triangular14-18 and pen-
tanuclear bow-tie cores.17 With the aim of extending this finding
to the chemistry of early transition metals, we have recently
synthesized the hydrosulfido-bridged heterodinuclear complex
[Cp2Ti(µ2-SH)2RuCl(η5-C5Me5)] (1) by the reaction of [Cp2-
Ti(SH)2] and [{(η5-C5Me5)Ru}4(µ3-Cl)4] (eq 1).21,22 Subsequent
1
Preparation of [(CpTi){(η5-C5Me5)Ru}{Ir(cod)}(µ3-S)2(µ2-Cl)]
(4b). Triethylamine (70 µL, 0.50 mmol) was added to a THF (5 mL)
solution of 1 (49.9 mg, 0.0967 mmol) at -78 °C. To the resultant deep
violet solution was added [{(cod)Ir}2(µ2-Cl)2] (31.9 mg, 0.0475 mmol)
at this temperature, and the mixture was slowly warmed to room
temperature with stirring. The resultant dark green solution was
evaporated to dryness and extracted with toluene (12 mL). Addition
of hexanes (18 mL) to the concentrated extract afforded dark brown
crystals of 4b, which were collected by filtration and dried in vacuo
1
self- or crossed-condensation reactions of 1 give rise to the
formation of the mixed-metal cubane-type sulfido clusters
[(CpTi)2{(η5-C5Me5)Ru}2(µ3-S)4] (2)21,22 and [(CpTi){(η5-C5-
Me5)Ru}3(µ3-S)4],23 which represent still rare examples of
mixed-metal sulfido clusters containing titanium.
(22.6 mg, 32%). H NMR (C6D6): δ 6.46 (s, 5H, C5H5), 4.33, 3.80,
2.25, 2.01 (br s, 2H each, cod), 1.81 (s, 15H, C5Me5). The other
methylene resonances (4H) for the cod ligand are masked by the C5-
Me5 singlet. Anal. Calcd for C23H32ClIrRuS2Ti: C, 36.87; H, 4.30.
Found: C, 36.69; H, 4.45.
Preparation of [(CpTiCl){(η5-C5Me5)Ru}{Pd(PPh3)2}(µ3-S)(µ2-
S)(µ2-H)] (5a). Triethylamine (1.4 mL, 10 mmol) was added to a THF
(100 mL) solution of 1 (1.039 g, 2.01 mmol) at -78 °C. To the resultant
deep violet solution was added [Pd(PPh3)4] (2.323 g, 2.01 mmol) at
this temperature, and the mixture was slowly warmed to room
temperature with stirring. The resultant violet solution was evaporated
to dryness. Extraction with benzene and subsequent recrystallization
from dichloromethane-hexanes (5 mL/45 mL) afforded deep violet
crystals of 5a along with an off-white powder; the latter was removed
by decantation with hexanes. Yield: 1.426 g (66%). 1H NMR (C6D6):
δ 7.7-6.7 (m, 30H, Ph), 6.11 (s, 5H, C5H5), 1.59 (s, 15H, C5Me5),
When attention is directed to the stepwise synthesis of
heterotrimetallic triangular sulfido clusters containing titanium,
the formation of 1 can be viewed as the first step of the cluster
synthesis by using hydrosulfido ligands as a template for
aggregation of three distinct metal fragments. The present study
addresses the final step of this bridge-assisted nuclearity
expansion to give trinuclear sulfido clusters containing the metal
atoms of the two extreme ends of the d block in the periodic
table. These trinuclear clusters have a TiRuMS2 core composi-
tion in common; however, the core structures depend strongly
upon the incoming metals M.
2
-11.92 (dd, 1H, JPH ) 114.7, 4.9 Hz, RuPdH). 31P{1H} NMR
(C6D6): δ 12.7, 8.2 (d, 1P each, 2JPP ) 64.9 Hz). Anal. Calcd for C51H51-
ClP2PdRuS2Ti: C, 56.67; H, 4.76. Found: C, 56.33; H, 4.85.
Preparation of [(CpTiCl){(η5-C5Me5)Ru}{Pt(PPh3)2}(µ3-S)(µ2-
S)(µ2-H)] (5b). A mixture of 1 (255.3 mg, 0.495 mmol) and [Pt(PPh3)4]
(615.6 mg, 0.495 mmol) in THF (40 mL) was stirred at room
temperature for 22 h. After removal of the solvent, the resultant dark
brown residue was recrystallized from dichloromethane-hexanes (5
mL/45 mL). Repeated recrystallization (three times) afforded 5b as
Experimental Section
General Considerations. All manipulations were carried out under
an atmosphere of nitrogen by using standard Schlenk techniques.
Solvents were dried by refluxing over Na/benzophenone ketyl (THF,
toluene, benzene, and hexanes) or P2O5 (dichloromethane) and distilled
before use. Triethylamine was distilled from KOH. Complex 1 was
prepared according to the literature.22 1H and 31P{1H} NMR spectra
were recorded on JEOL EX-270 and LA-400 spectrometers. Elemental
analyses were performed on a Perkin-Elmer 2400II CHN analyzer.
Preparation of [(CpTi){(η5-C5Me5)Ru}{Ru(PPh3)2}(µ3-S)2(µ2-
Cl)2] (3). Triethylamine (400 µL, 2.9 mmol) was added to a THF (20
mL) solution of 1 (277.5 mg, 0.538 mmol) at -78 °C. To the resultant
deep violet solution was added [RuCl2(PPh3)3] (516.1 mg, 0.538 mmol)
at this temperature, and the mixture was slowly warmed to room
temperature with stirring. After removal of the solvent in vacuo, the
resultant dark red residue was extracted with benzene (10 mL). The
extract was evaporated to dryness and recrystallized from THF-hexanes
(10 mL/40 mL). The dark brown crystals that formed were filtered
off, washed with hexanes (3 mL × 2), and dried in vacuo (378.4 mg,
1
dark brown crystals (23.7 mg, 4%). H NMR (C6D6): δ 7.7-6.7 (m,
30H, Ph), 6.20 (s, 5H, C5H5), 1.58 (s, 15H, C5Me5), -11.54 (dd with
2
1
195Pt satellites, 1H, JPH ) 119.6, 14.6 Hz, JPtH ) 666.2 Hz, RuPtH).
31P{1H} NMR (C6D6): δ 10.9 (d with 195Pt satellites, 1P, JPP ) 21.6
2
Hz, 1JPtP ) 3659.9 Hz), 8.1 (d with 195Pt satellites, 1P, 2JPP ) 21.6 Hz,
1JPtP ) 3415.3 Hz). Anal. Calcd for C51H51ClP2PtRuS2Ti: C, 52.38;
H, 4.40. Found: C, 52.03; H, 4.46.
X-ray Diffraction Studies. Single crystals suitable for X-ray
analyses were sealed in glass capillaries under an inert atmosphere and
mounted on a Rigaku AFC7R four-circle diffractometer equipped with
a graphite-monochromatized Mo KR source (λ ) 0.710 69 Å).
Orientation matrixes and unit cell parameters were determined by least-
squares treatment of 25 machine-centered reflections with 25° < 2θ <
40°. The data collection was performed at 294 K using the ω-2θ scan
(for 3, 4a, and 4b) or ω-scan (for 5a and 5b) technique at a rate of 32°
min-1 to a maximum 2θ value of 55°. The intensities of 3 check
reflections were monitored every 150 reflections during data collection,
which revealed no significant decay. Intensity data were corrected for
Lorentz-polarization effects and for absorption (ψ scans). Details of
crystal and data collection parameters are summarized in Table 1.
Structure solution and refinements were carried out by using the
teXsan program package.24 The heavy-atom positions were determined
by a Patterson method program (DIRDIF92-PATTY25), and the
remaining non-hydrogen atoms were found by subsequent Fourier
1
63%). H NMR (C6D6): δ 7.8-6.9 (m, 30H, Ph), 6.40 (s, 5H, C5H5),
1.48 (s, 15H, C5Me5). 31P{1H} NMR (C6D6): δ 33.6 (s). Anal. Calcd
for C51H50Cl2P2Ru2S2Ti: C, 55.19; H, 4.54. Found: C, 55.47; H, 4.75.
Preparation of [(CpTi){(η5-C5Me5)Ru}{Rh(cod)}(µ3-S)2(µ2-Cl)]
(4a). Triethylamine (340 µL, 2.45 mmol) was added to a THF (25 mL)
solution of 1 (249.0 mg, 0.483 mmol) at -78 °C. To the resultant deep
violet solution was added [{(cod)Rh}2(µ2-Cl)2] (119.9 mg, 0.243 mmol)
at this temperature, and the mixture was slowly warmed to room
temperature with stirring. The resultant dark green solution was
evaporated to dryness and extracted with toluene (30 mL). Addition
of hexanes (40 mL) to the concentrated extract afforded dark brown
(20) Kochi, T.; Tanabe, Y.; Tang, Z.; Ishii, Y.; Hidai, M. Chem. Lett. 1999,
1279-1280.
(24) teXsan: Crystal Structure Analysis Package; Molecular Structure
Corp.: The Woodlands, TX, 1985 and 1992.
(25) PATTY94: Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman,
W. P.; de Gelder, R.; Israel, R.; Smits, J. M. M. The DIRDIF-94
Program System; Technical Report of the Crystallography Laboratory,
University of Nijmegen, Nijmegen, The Netherlands, 1994.
(21) Kuwata, S.; Hidai, M. Chem. Lett. 1998, 885-886.
(22) Kabashima, S.; Kuwata, S.; Hidai, M. J. Am. Chem. Soc. 1999, 121,
7837-7845.
(23) Kabashima, S.; Kuwata, S.; Ueno, K.; Shiro, M.; Hidai, M. Angew.
Chem., Int. Ed. 2000, 39, 1128-1131.

2036 Inorganic Chemistry, Vol. 40, No. 9, 2001
Kuwata et al.
Table 1. X-ray Crystallographic Data for 3, 4a, 4b, 5a, and 5b
3
4a
4b
5a
5b
formula
fw
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
C51H50Cl2P2Ru2S2Ti
1109.97
P1h (No. 2)
12.448(4)
12.773(4)
17.270(4)
100.16(2)
99.93(2)
114.11(3)
2373(1)
2
1.553
1.56
10.95
0.045
0.045
0.044
C23H32ClRhRuS2Ti
659.95
C23H32ClIrRuS2Ti
749.27
C51H51ClP2PdRuS2Ti
1080.85
P21/c (No. 14)
11.259(4)
16.438(4)
26.092(5)
90
102.23(3)
90
4719(2)
4
1.521
1.53
11.06
0.023
0.042
0.046
C51H51ClP2PtRuS2Ti
1169.54
P21/n (No. 14)
11.369(2)
16.207(3)
26.116(2)
90
102.29(1)
90
4701(1)
4
1.652
1.64
36.87
0.094
0.050
0.054
P1h (No. 2)
7.714(2)
11.598(3)
14.802(4)
80.46(2)
82.53(2)
71.47(2)
1234.0(6)
2
1.776
1.78
18.65
0.016
P1h (No. 2)
7.729(1)
11.577(2)
14.766(3)
80.14(1)
82.71(1)
71.55(1)
1231.1(4)
2
F
calcd, g cm-3
obsd, g cm-3
2.021
F
µ(Mo KR), cm-1
66.15
0.018
0.038
0.053
Rint
Ra
0.042
0.054
b
Rw
2
2
a R ) ∑||Fo| - |Fc||/∑|Fo|. b Rw ) [∑w(|Fo| - |Fc|)2/∑wFo ]1/2, w ) [σc2(Fo) + p2Fo /4]-1 (p ) 0.020 (3 and 5b), 0.025 (4a), 0.030 (4b),
0.015(5a)) with σc(Fo) from counting statistics.
C5Me5)] and [CpTi(µ2-S)2Ru(η5-C5Me5)] is generated at this
syntheses. The C5Me5 carbon atoms in 4a, 4b, 5a, and 5b were found
to be disordered and refined isotropically as rigid groups with
stage. Formation of the corresponding coordinatively unsaturated
intermediates [(η5-C5Me5)M(µ2-S)2M(η5-C5Me5)] (M ) Ru, Ir)
occupancies of 60 and 40% (in 4a and 4b), or 55 and 45% (in 5a and
5b). All non-hydrogen atoms except for these carbon atoms were refined
from [(η5-C5Me5)MCl(µ2-SH)2MCl(η5-C5Me5)] and triethyl-
anisotropically by full-matrix least-squares techniques (based on F).
The hydrido hydrogen atoms in 5a and 5b were found in the final
difference Fourier maps. All other hydrogen atoms except for those in
the disordered C5Me5 groups in 4a, 4b, 5a, and 5b were placed at
calculated positions; these hydrogen atoms were included in the final
stages of refinements with fixed parameters. The atomic scattering
factors were taken from ref 26, and anomalous dispersion effects were
included; the values of ∆f′ and ∆f′′ were taken from ref 27.
1
amine is deduced from the H NMR spectrum of the reaction
mixture15,29 or a trapping experiment with alkynes.19 These
observations prompted us to examine the reaction of this violet
solution with mononuclear ruthenium complexes at -78 °C.
When the mixture of the violet solution and [RuCl2(PPh3)3] was
warmed to room temperature, the TiRu2 cluster [(CpTi){(η5-
C5Me5)Ru}{Ru(PPh3)2}(µ3-S)2(µ2-Cl)2] (3) was obtained in 63%
yield (eq 2). The 1H NMR spectrum of 3 exhibits signals
Results and Discussion
Synthesis and Structure of TiRu2 Cluster 3. We have
already demonstrated that the hydrosulfido-bridged homodi-
nuclear complexes [(η5-C5Me5)MCl(µ2-SH)2MCl(η5-C5Me5)]
(M ) Ru, Ir) react with [RuH2(PPh3)4] to afford the sulfido-
capped trinuclear clusters [{(η5-C5Me5)Ru}2(µ3-S)2(µ2-H)RuCl-
(PPh3)2]19 and [{(η5-C5Me5)Ir}2(µ3-S)2RuCl2(PPh3)],18 respec-
tively. On the basis of these findings, we first attempted the
reaction of the hydrosulfido-bridged titanium-ruthenium com-
plex 1 with [RuH2(PPh3)4]. Isolated from the reaction mixture
were, however, the cubane-type cluster [(CpTi)2{(η5-C5Me5)-
Ru}2(µ3-S)4] (2) and [CpRuH(PPh3)2].28 Although the detailed
reaction mechanism is obscure, formation of the latter complex
may be explained by the reaction of [RuH2(PPh3)4] with
cyclopentadiene, which is eliminated from 1. Indeed, base-
induced elimination of cyclopentadiene and HCl from 1 to give
2 has already been established.21,22 The reaction of 1 with
[RuCl2(PPh3)3] was also attempted, which afforded a complex
mixture containing [Cp2TiCl2] and unidentified products.
At this juncture, we turned our attention to a coordinatively
unsaturated species derived from the hydrosulfido complex 1.
We have previously observed that a dark reddish brown solution
of 1 turns deep violet upon treatment with triethylamine at -78
°C; the reaction gives the dark reddish brown Ti2Ru2 cubane-
type cluster 2 as the final product.21,22 Although this violet
species remains uncharacterized, it is probable that a coordi-
natively unsaturated species such as [Cp2Ti(µ2-S)(µ2-SH)Ru(η5-
ascribed to the Cp, C5Me5, and PPh3 protons in an intensity
ratio of 5:15:30, suggesting that a Ru(PPh3)2 fragment is
incorporated into the TiRuS2 core derived from 1. No signals
attributable to hydrosulfido or hydrido resonances are observed.
The integral ratio also indicates that one of the Cp ligands in 1
has been lost during the reaction, as in the transformation of 1
into the cubane-type cluster 2. On the other hand, the reaction
using [RuH2(PPh3)4] instead of [RuCl2(PPh3)3] afforded a
complex mixture containing [CpRuH(PPh3)2] and 2.
The trinuclear structure of 3 has been confirmed further by
an X-ray analysis (Figure 1); selected interatomic distances and
angles are listed in Table 2. The TiRu2 triangle is capped by
two µ3-sulfido ligands, and the Ti-Ru(1) and Ru(1)-Ru(2)
edges are bridged by a chloro ligand, which is almost coplanar
with the three metal atoms. It is noteworthy that the Cl(2) atom
is coordinated in a “semibridging” manner as substantiated by
the unusually long Ru(1)-Cl(2) (2.563(2) Å) and the normal
Ru(2)-Cl(2) (2.390(2) Å) distances. In contrast, the two capping
sulfido ligands are located closer to the Ru(1) atom than to the
Ru(2) atom: the Ru(1)-S distances (2.408 Å (mean)) are
significantly shorter than the Ru(2)-S distances (2.513 Å
(mean)).
(26) International Tables for X-ray Crystallography; Kynoch Press: Bir-
mingham, U.K., 1974; Vol. IV.
(27) International Tables for X-ray Crystallography; Kluwer Academic:
Boston, MA, 1992; Vol. C.
(28) Baird, G. J.; Davies, S. G.; Moon, S. D.; Simpson, S. J.; Jones, R. H.
J. Chem. Soc., Dalton Trans. 1985, 1479-1486.
(29) Tang, Z.; Nomura, Y.; Ishii, Y.; Mizobe, Y.; Hidai, M. Inorg. Chim.
Acta 1998, 267, 73-79.

Heterobimetallic and Heterotrimetallic Sulfido Clusters
Inorganic Chemistry, Vol. 40, No. 9, 2001 2037
sulfido complexes32-36 along with hydrosulfido,13-18,37-39
disulfido,40-43 and thiolato44 complexes as building blocks. In
the resultant MM′2 heterobimetallic clusters, however, the
ancillary ligands on the two M′ atoms are usually the same ones.
Stepwise incorporation of M′ typified by eqs 1 and 2 enables
the preparation of MM′2 heterobimetallic clusters with two site-
differentiated M′ centers.
Synthesis of TiRuM (M ) Rh, Ir) Heterotrimetallic
Clusters 4. According to the procedure for the synthesis of the
TiRu2 cluster 3, the TiRuM heterotrimetallic clusters [(CpTi)-
{(η5-C5Me5)Ru}{M(cod)}(µ3-S)2(µ2-Cl)] (M ) Rh (4a), Ir (4b))
were successfully obtained from the hydrosulfido-bridged
titanium-ruthenium complex 1 and [{(cod)M}2(µ2-Cl)2] with
the aid of triethylamine (eq 3). As in the preparation of 3,
Figure 1. Structure of 3. Thermal ellipsoids are shown at the 30%
probability level. Hydrogen atoms are omitted for clarity.
Table 2. Selected Interatomic Distances (Å) and Angles (deg) for 3
Ti-Ru(1)
Ti-Ru(2)
Ti-S(1)
3.032(1)
2.714(1)
2.266(2)
2.269(2)
2.357(2)
3.188(2)
2.408(2)
2.408(2)
Ru(1)-Cl(2)
Ru(2)-S(1)
Ru(2)-S(2)
Ru(2)-Cl(1)
Ru(2)-Cl(2)
Ru(2)-P(1)
Ru(2)-P(2)
2.563(2)
2.521(2)
2.504(2)
2.432(2)
2.390(2)
2.370(2)
2.343(2)
Ti-S(2)
Ti-Cl(1)
treatment of 1 with triethylamine prior to addition of the group
9 metal complexes proved to be essential, because the reaction
barely took place without triethylamine at room temperature.
The 1H NMR spectra of 4 indicate the presence of the Cp, C5-
Me5, and cod ligands in a ratio of 1:1:1, suggesting the TiRuM
core composition of 4.
The detailed structures of both 4a and 4b have been
determined by X-ray crystallography (Figure 2); selected bond
distances and angles are listed in Table 3. The structures of
these two clusters are essentially identical. Thus, clusters 4 have
a TiRuM (M ) Rh, Ir) triangular core with two capping sulfido
ligands. Furthermore, a semibridging Cl ligand attaches to the
Ti-Ru edge with long Ru-Cl distances of 2.574(2) Å (in 4a)
and 2.558(2) Å (in 4b); the Ti-Cl distances (4a, 2.344(2) Å;
4b, 2.350(2) Å) are comparable to that in 3 (2.357(2) Å). The
remarkably acute Ti-Cl-Ru angle (4a, 66.27(5)°; 4b, 66.86-
(5)°) as well as the Ti-Ru distances (4a, 2.695(1) Å; 4b, 2.710-
(2) Å) indicates the presence of a Ti-Ru bond. The Ti-Rh
distance in 4a (2.941(1) Å) falls in the range of those found in
Ru(1)-Ru(2)
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-Ti-Ru(2)
Ti-S(1)-Ru(1)
Ti-S(1)-Ru(2)
67.12(3) Ti-S(2)-Ru(2)
80.83(7) Ru(1)-S(2)-Ru(2)
68.85(6) Ti-Cl(1)-Ru(2)
69.12(6)
80.91(6)
69.04(5)
Ru(1)-S(1)-Ru(2) 80.56(6) Ru(1)-Cl(2)-Ru(2) 80.03(6)
Ti-S(2)-Ru(1) 80.76(7)
In the titanium-ruthenium heterobimetallic compounds re-
ported so far, the Ti-Ru bond distances are put into two
categories: one is found in complexes containing Ti-Ru bonds
without bridging ligands (2.503(1)-2.663(1) Å)30,31 and the
other in cubane-type sulfido clusters synthesized by our group
(2.904(2)-3.0158(8) Å).21-23 The Ti-Ru(2) distance of 2.714-
(1) Å in the present TiRu2 cluster 3 lies in the middle of these
two categories, and the remarkably acute Ti-Cl(1)-Ru(2) and
Ti-S-Ru(2) angles (69.0° (mean)) in 3 further support the
presence of a Ti-Ru bond. On the other hand, the Ti-Ru(1)
distance (3.032(1) Å) is much longer than the Ti-Ru(2)
distance. However, it is only slightly longer than those of the
latter category of Ti-Ru bond distances and still suggests the
presence of some bonding interaction. In contrast to these Ti-
Ru interactions, the Ru(1)-Ru(2) separation of 3.188(2) Å in
3 precludes any direct metal-metal bonding. The metal-metal
bonding scheme is apparently inconsistent with the effective
atomic number (EAN) rule, because the total electron count of
3 is 48 when the “semibridging” chloro ligand is treated as a
bridging ligand. This can be accounted by the weak tendency
of early transition metals to attain an 18e- configuration. If the
metal-metal interactions are neglected, the coordination ge-
ometry around the Ti and Ru(1) atoms is a three-legged piano-
stool geometry, whereas that around the Ru(2) atom is distorted
octahedral.
(32) Tatsumi, K.; Kawaguchi, H.; Inoue, Y.; Nakamura, A.; Cramer, R.
E.; Golen, J. A. Angew. Chem., Int. Ed. Engl. 1993, 32, 763-765.
(33) Lang, J.-P.; Tatsumi, K. J. Organomet. Chem. 1999, 579, 332-337.
(34) Eremenko, I. L.; Rosenberger, S.; Nefedov, S. E.; Berke, H.;
Novotortsev, V. M. Inorg. Chem. 1995, 34, 830-840.
(35) Ikada, T.; Kuwata, S.; Mizobe, Y.; Hidai, M. Inorg. Chem. 1999, 38,
64-69 and references therein.
(36) Fong, S.-W. A.; Hor, T. S. A. J. Chem. Soc., Dalton Trans. 1999,
639-651.
(37) Casado, M. A.; Pe´rez-Torrente, J. J.; Ciriano, M. A.; Edwards, A. J.;
Lahoz, F. J.; Oro, L. A. Organometallics 1999, 18, 5299-5310.
(38) Hernandez-Gruel, M. A. F.; Pe´rez-Torrente, J. J.; Ciriano, M. A.;
Lo´pez, J. A.; Lahoz, F. J.; Oro, L. A. Eur. J. Inorg. Chem. 1999,
2047-2050.
(39) Hernandez-Gruel, M. A. F.; Pe´rez-Torrente, J. J.; Ciriano, M. A.;
Lahoz, F. J.; Oro, L. A. Angew. Chem., Int. Ed. 1999, 38, 2769-
2771.
(40) Okazaki, M.; Yuki, M.; Kuge, K.; Ogino, H. Coord. Chem. ReV. 2000,
By virtue of the versatile coordination ability of sulfur, a
number of triangular sulfido clusters containing two distinct
metals have been synthesized by using terminal or bridging
198, 367-378.
(41) Pasynskii, A. A.; Kolobkov, B. I.; Nefedov, S. E.; Eremenko, I. L.;
Koltun, E. S.; Yanovsky, A. I.; Struchkov, Y. T. J. Organomet. Chem.
1993, 454, 229-236.
(42) Kuwata, S.; Mizobe, Y.; Hidai, M. J. Am. Chem. Soc. 1993, 115,
8499-8500.
(30) Gade, L. H.; Schubart, M.; Findeis, B.; Fabre, S.; Bezougli, I.; Lutz,
M.; Scowen, I. J.; McPartlin, M. Inorg. Chem. 1999, 38, 5282-5294.
(31) Friedrich, S.; Memmler, H.; Gade, L. H.; Li, W.-S.; Scowen, I. J.;
McPartlin, M.; Housecroft, C. E. Inorg. Chem. 1996, 35, 2433-2441
and references therein.
(43) Adams, R. D.; Babin, J. E.; Wang, J.-G.; Wu, W. Inorg. Chem. 1989,
28, 703-709.
(44) Ciriano, M. A.; Pe´rez-Torrente, J. J.; Lahoz, F. J.; Oro, L. A. J. Chem.
Soc., Dalton Trans. 1992, 1831-1837.

2038 Inorganic Chemistry, Vol. 40, No. 9, 2001
Kuwata et al.
of 2.878(1) Å in 4b is comparable to those found in [CpTi(µ3-
S)3Ir3(µ2-CO)(CO)3{P(OMe)3}3] (2.815 Å (mean of the shorter
distances)),48 [TiCl2(µ2-S)2Ir(PMe3)(η5-C5Me5)] (2.899(1) Å),49
and [CpTiCl(µ2-S)2Ir(PMe3)(η5-C5Me5)] (2.989(2) Å),49 in
which the presence of an Ir-Ti dative bond is suggested. On
the other hand, the Ru-Rh(Ir) distances of 3.018(1) and 2.9535-
(6) Å in 4 indicate that the interactions between these metal
atoms are relatively weak, when these distances are compared
with, for example, the Ru-Rh distances found in [{(η5-C5Me5)-
Ru}2(µ2-H)(µ3-S)2RhCl2(PPh3)] (2.773 Å (mean)).14 This is
partially because of the high-lying atomic pz orbital perpen-
dicular to the coordination plane of the Rh(Ir) atom.50 We also
note that the Ru-Ir distance in 4b is still close to those in [{(η5-
C5Me5)Ir}2(µ3-S)2RuMe(dppe)][PF6] (2.8695(8) and 2.978(1) Å;
dppe ) Ph2PCH2CH2PPh2).18 As a consequence of the electron-
deficient nature of titanium, clusters 4 have only 46 electrons.
With regard to a related reaction, the hydrosulfido-bridged
homodinuclear complexes [(η5-C5Me5)MCl(µ2-SH)2MCl(η5-C5-
Me5)] (M ) Rh, Ir) are known to react with [{(cod)Rh}2(µ2-
Cl)2] to afford the 48e- RhM2 clusters [{(η5-C5Me5)M}2(µ3-
S)2Rh(cod)]+ with three metal-metal bonds.15 Unlike the
formation of 4, these reactions take place without addition of
bases. Oro, Ciriano, and co-workers have recently prepared the
Zr-Rh-Ir heterotrimetallic triangular cluster [(Cptt Zr){Rh-
2
(cod)}{Ir(CO)2}(µ3-S)2] (Cptt ) η5-C5H3But2-1,3) by the salt-
elimination reaction of the sulfido-bridged zirconium-iridium
anion [Cptt Zr(µ2-S)2Ir(CO)2]- with [{(cod)Rh}2(µ2-Cl)2].39 This
2
ZrRhIr cluster has a Rh-Ir bond, whereas there seems to be
no significant interaction between the d0 zirconium center and
the d8 late-transition-metal centers. The heterotrimetallic trian-
gular cluster [PPN]2[CrMoW(µ3-S)(µ2-CO)3(CO)9] (PPN )
(Ph3P)2N+) has also been synthesized by a bridge-assisted
nuclearity expansion from the hydrosulfido complex [PPN]-
[W(SH)(CO)5].51 In contrast to 4, these clusters contain more
than two metals that belong to the same group in the periodic
table.
Synthesis and Structures of TiRuM (M ) Pd, Pt) Het-
erotrimetallic Clusters 5. Successful isolation of clusters 3 and
4 encouraged us to apply the same synthetic procedure to group
10 metals. As expected, complex 1 reacted with [Pd(PPh3)4]
and triethylamine to afford the TiRuPd cluster [(CpTiCl){(η5-
C5Me5)Ru}{Pd(PPh3)2}(µ3-S)(µ2-S)(µ2-H)] (5a), as shown in
eq 4. Although the reaction of 1 with [Pd(PPh3)4] alone also
Figure 2. Structures of (a) 4a and (b) 4b. Thermal ellipsoids are shown
at the 30% probability level. Hydrogen atoms and the minor component
of the disordered C5Me5 groups are omitted for clarity.
Table 3. Selected Bond Distances (Å) and Angles (deg) for
4a and 4b
4a (M ) Rh)
4b (M ) Ir)
Ti-Ru
2.695(1)
2.941(1)
2.275(2)
2.279(2)
2.344(2)
3.018(1)
2.427(2)
2.444(2)
2.574(2)
2.356(2)
2.355(2)
2.710(2)
2.878(1)
2.292(2)
2.283(2)
2.350(2)
2.9535(6)
2.445(2)
2.432(2)
2.558(2)
2.347(2)
2.352(2)
Ti-M
Ti-S(1)
Ti-S(2)
Ti-Cl
Ru-M
Ru-S(1)
Ru-S(2)
Ru-Cl
M-S(1)
M-S(2)
Ru-Ti-M
Ti-Ru-M
Ti-M-Ru
Ti-S(1)-Ru
Ti-S(1)-M
Ru-S(1)-M
Ti-S(2)-Ru
Ti-S(2)-M
Ru-S(2)-M
Ti-Cl-Ru
64.59(3)
61.66(3)
53.75(3)
69.85(5)
78.84(6)
78.24(5)
69.48(6)
78.77(6)
77.93(6)
66.27(5)
63.73(3)
60.91(3)
55.36(3)
69.69(7)
76.67(6)
76.06(6)
70.07(6)
76.75(6)
76.21(5)
66.86(5)
took place to give 5a, addition of triethylamine made isolation
of 5a easier. On the other hand, the reaction of 1 with [Pt-
(PPh3)4] was rather complicated. The reaction mixture was found
related Ti-Rh sulfido clusters such as [(CpTi)2{Rh(cod)}2(µ3-
S)4],45 [CpTi(µ3-S)3{Rh(tfbb)}3] (tfbb ) tetrafluorobenzobar-
relene),46 and [(CpTi)2{Rh(CO)}2{Rh(CO)[P(OPh)3]}2(µ4-O)-
(µ3-S)4] (2.8779(7)-3.056(1) Å).47 Similarly, the Ti-Ir distance
(48) Casado, M. A.; Ciriano, M. A.; Edwards, A. J.; Lahoz, F. J.; Oro, L.
A.; Pe´rez-Torrente, J. J. Organometallics 1999, 18, 3025-3034.
(49) Nagano, T.; Kuwata, S.; Ishii, Y.; Hidai, M. Organometallics 2000,
19, 4176-4178.
(50) Mingos, D. M. P.; May, A. S. In The Chemistry of Metal Cluster
Complexes; Shriver, D. F., Kaesz, H. D., Adams, R. D., Eds.; VCH:
New York, 1990; pp 11-119.
(51) Darensbourg, D. J.; Zalewski, D. J.; Sanchez, K. M.; Delord, T. Inorg.
Chem. 1988, 27, 821-829.
(45) Amemiya, T.; Kuwata, S.; Hidai, M. Chem. Commun. 1999, 711-
712.
(46) Atencio, R.; Casado, M. A.; Ciriano, M. A.; Lahoz, F. J.; Pe´rez-
Torrente, J. J.; Tiripicchio, A.; Oro, L. A. J. Organomet. Chem. 1996,
514, 103-110.
(47) Casado, M. A.; Ciriano, M. A.; Edwards, A. J.; Lahoz, F. J.; Pe´rez-
Torrente, J. J.; Oro, L. A. Organometallics 1998, 17, 3414-3416.

Heterobimetallic and Heterotrimetallic Sulfido Clusters
Inorganic Chemistry, Vol. 40, No. 9, 2001 2039
Table 4. Selected Interatomic Distances (Å) and Angles (deg) for
5a and 5b
5a (M ) Pd)
5b (M ) Pt)
Ti-Ru
2.821(1)
3.270(1)
2.338(2)
2.210(2)
2.349(2)
2.8972(5)
2.297(1)
2.356(2)
1.75
2.344(1)
2.378(1)
2.329(1)
1.77
2.836(2)
3.331(2)
2.355(3)
2.208(3)
2.336(3)
2.9043(8)
2.324(2)
2.361(3)
1.69
2.341(2)
2.324(2)
2.283(2)
1.79
Ti-M
Ti-S(1)
Ti-S(2)
Ti-Cl
Ru-M
Ru-S(1)
Ru-S(2)
Ru-H(36)
M-S(1)
M-P(1)
M-P(2)
M-H(36)
Ti-Ru-M
69.74(2)
74.98(4)
88.59(5)
77.25(4)
76.25(5)
70.93(4)
74.62(8)
90.34(9)
77.01(7)
76.65(9)
Ti-S(1)-Ru
Ti-S(1)-M
Ru-S(1)-M
Ti-S(2)-Ru
distances and angles are listed in Table 4. The structures of
both clusters are closely related to each other. The Ti-Ru
distances (5a, 2.821(1) Å; 5b, 2.836(2) Å) are slightly longer
than those found in 3 and 4 but still indicate the presence of a
metal-metal bond. In each complex, a hydrido ligand, which
has been found in the final difference Fourier map, bridges the
Ru-Pd and Ru-Pt edge to form a three-center-two-electron
bond (Ru-Pd, 2.8972(5) Å; Ru-Pt, 2.9043(8) Å). On the other
hand, the long Ti-Pd and Ti-Pt distances (3.270(1) and 3.331-
(2) Å) suggest the absence of direct Ti-Pd(Pt) interactions. If
these metal-metal interactions are neglected, the Ti and Ru
center have three-legged piano-stool geometries, whereas the
Pd and Pt centers lie in a square-planar environment.
The M3(µ3-S)(µ2-S) framework found in 5 is unprecedented
for clusters with M3S2 composition.53 Indeed, the long Pd-
S(2) and Pt-S(2) distances of 4.030(2) and 4.062(2) Å clearly
distinguish the TiRuPdS2 and TiRuPtS2 cores in 5 from the
typical M3(µ3-S)2 one. It is also to be noted that the Ti-(µ2-S)
distances (5a, 2.210(2) Å; 5b, 2.208(3) Å) are significantly
shorter than the Ti-(µ3-S) distances (5a, 2.338(2) Å; 5b, 2.355-
(3) Å) and are comparable to the TidS double-bond distances
(2.111-2.217(1) Å).54-57 In contrast, the Ru-(µ2-S) distances
(5a, 2.356(2) Å; 5b, 2.361(3) Å) are slightly longer than the
Ru-(µ3-S) distances (5a, 2.297(1) Å; 5b, 2.324(2) Å). The
chloro ligand is bonded to the Ti atom as a terminal ligand with
the Pd-Cl and Pt-Cl nonbonding contacts of 3.203(2) and
3.379(3) Å.
We have already demonstrated that the hydrosulfido-bridged
diiridium complex [(η5-C5Me5)IrCl(µ2-SH)2IrCl(η5-C5Me5)] re-
acts with [Pd(PPh3)4] to afford the Ir2Pd cluster [{(η5-C5Me5)-
Ir}2(µ3-S)2PdCl(PPh3)]Cl.15 Interestingly, the corresponding
reaction of the diruthenium complex [(η5-C5Me5)RuCl(µ2-SH)2-
RuCl(η5-C5Me5)] leads to the formation of the ruthenium-
palladium cluster [{(η5-C5Me5)Ru}2(µ3-S)2{Pd(PPh3)}2(µ2-
Cl)]Cl with a Ru2Pd2 composition.58 In these reactions, including
the formation of 5, the sum of the formal oxidation number of
Figure 3. Structures of (a) 5a and (b) 5b. Thermal ellipsoids are shown
at the 30% probability level. Hydrogen atoms, except for the hydrido
ligand, and the minor component of the disordered C5Me5 groups are
omitted for clarity.
to contain the Ti2Ru2 cubane-type cluster 2 and trans-[PtHCl-
(PPh3)2]52 along with the desired TiRuPt cluster, [(CpTiCl)-
{(η5-C5Me5)Ru}{Pt(PPh3)2}(µ3-S)(µ2-S)(µ2-H)] (5b). Fortu-
nately, we succeeded in isolating 5b by repeated recrystallization,
although the yield was low. Addition of triethylamine did not
improve the yield of 5b.
1
The H NMR spectra of 5 exhibit a hydrido resonance as a
doublet of doublets, and in the case of the platinum cluster 5b,
the signal is further accompanied by 195Pt satellites. The larger
2JPH values (5a, 114.7 Hz; 5b, 119.6 Hz) are ascribed to the
coupling with the phosphorus nucleus trans to the hydrido
ligand, whereas the smaller values (5a, 4.9 Hz; 5b, 14.6 Hz)
are ascribed to that with the cis ligand. The inequivalency of
the two phosphine ligands is also indicated by two mutually
coupled signals in the 31P{1H} NMR spectra of 5; Pt-P
(53) Dance, I.; Kisher, K. Prog. Inorg. Chem. 1994, 41, 637-803.
(54) Krug, V.; Koellner, G.; Mu¨ller, U. Z. Naturforsch., B 1988, 43, 1501-
1509.
1
couplings with the JPtP values of 3659.9 and 3415.3 Hz are
also observed for 5b.
(55) Hagadorn, J. R.; Arnold, J. Inorg. Chem. 1997, 36, 2928-2929.
(56) Sweeney, Z. K.; Polse, J. L.; Andersen, R. A.; Bergman, R. G.;
Kubinec, M. G. J. Am. Chem. Soc. 1997, 119, 4543-4544.
(57) Lundmark, P. J.; Kubas, G. J.; Scott, B. L. Organometallics 1996,
15, 3631-3633.
The structures of 5a and 5b determined by X-ray crystal-
lography are depicted in Figure 3, and selected interatomic
(52) Collamati, I.; Furlani, A.; Attioli, G. J. Chem. Soc. A 1970, 1694-
1696.
(58) Kuwata, S.; Hashizume, K.; Mizobe, Y.; Hidai, M. Unpublished results.

2040 Inorganic Chemistry, Vol. 40, No. 9, 2001
Kuwata et al.
the metals is increased by 2. If oxidation of the metal atoms
does not take place as in eqs 2 and 3, it would be expected that
[(CpTi){(η5-C5Me5)Ru}{M(PPh3)2}(µ3-S)2] (6) is formed. We
thus attempted the dehydrochlorination of 5a with strong bases
such as NaN(SiMe3)2. Being consistent with the formation of 6
(M ) Pd), the 1H NMR spectrum of the reaction mixture
exhibited new singlets at 6.18 and 1.49 ppm in an intensity ratio
of 5:15 along with the signals ascribed to the Ti2Ru2 cubane-
type cluster 2. However, further characterization of this new
species has been unsuccessful so far.
involved, however, the TiRuMS2 cores are significantly de-
formed from a symmetrical M3S2 trigonal bipyramid, depending
notably upon the incoming metal M. Such deformation leads
to the structural characteristics exemplified by the unprecedented
M3(µ3-S)(µ2-S) core in 5 and the “semibridging” chloro ligand
in 3 and 4. In addition, clusters 3-5 do not obey the EAN rule
because of the electron-deficient nature of titanium.
It is also to be emphasized that clusters 3-5 contain more
than two very different metal centers with labile chloro,
organophosphine, and olefinic coligands in close proximity. We
believe cooperative reactivities are elicited from these early-
late heterometallic centers.59 Further investigation will be
directed toward this line.
Concluding Remarks
We have systematically synthesized heterometallic triangular
sulfido clusters 3-5 bearing TiRu2 and TiRuM (M ) Rh, Ir,
Pd, Pt) cores by stepwise accumulation of two distinct metal
fragments onto the hydrosulfido complex [Cp2Ti(SH)2]. These
clusters have been added to the cluster library as a novel class
of compounds. It is of special note that, to the best of our
knowledge, clusters 4 and 5 represent the first examples of
heterotrimetallic triangular clusters containing titanium. All of
the clusters synthesized in the present study have a TiRuMS2
core composition in common, along with a chloro ligand bound
to the Ti atom. Owing to the different nature of the metals
Acknowledgment. This work was supported by a Grant-
in-Aid for Specially Promoted Research (09102004 and
12750755) from the Ministry of Education, Science, Sports, and
Culture of Japan.
Supporting Information Available: X-ray crystallographic files
in CIF format for 3, 4a, 4b, 5a, and 5b. This material is available free
of charge via the Internet at http://pubs.acs.org.
IC0009324
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