Stepwise formation of heterometallic cluster compounds (C5Me5)WRu5(μ6-C)(μ-CCH 2Ph)(μ-H)2(CO)13 and (C5Me 5)WRU5(μ4-C)(μ3-C

Article abstract of DOI:10.1021/om970211l

Treatment of the carbido cluster Ru₅(μ₅-C)(CO)₁₅ with Me₃NO followed by addition of the tungsten acetylide complexes LW(CO)₃(CCPh) (L = Cp, C₅Me₅) affords the two heterometallic

Full text of DOI:10.1021/om970211l

Organometallics 1997, 16, 3523-3530
3523
Step w ise F or m a tion of Heter om eta llic Clu ster
Com p ou n d s (C5Me5)WRu 5(µ6-C)(µ-CCH2P h )(µ-H)2(CO)13
a n d (C5Me5)WRu 5(µ4-C)(µ3-CCH2P h )(µ-H)4(CO)12 fr om
Ru 5(µ5-C)(CO)15. Rea ctivity Stu d ies of Ca r bid o Clu ster s
Bea r in g Acetylid e Liga n d s
Wen-J i Chao,† Yun Chi,*,† Ching-J uh Way,† Ipe J . Mavunkal,† Sue-Lein Wang,†
Fen-Ling Liao,† and Louis J . Farrugia*,‡
Departments of Chemistry, National Tsing Hua University, Hsinchu 30043, Taiwan, ROC,
and The University, Glasgow G12 8QQ, Scotland, U.K.
Received March 17, 1997X
Treatment of the carbido cluster Ru5(µ5-C)(CO)15 with Me3NO followed by addition of the
tungsten acetylide complexes LW(CO)3(CCPh) (L ) Cp, C5Me5) affords the two heterometallic
cluster complexes LWRu5(µ5-C)(CCPh)(CO)15 (1a , L ) Cp; 1b, L ) C5Me5) and LWRu5(µ5-
C)(CCPh)(CO)13 (2a , L ) Cp; 2b, L ) C5Me5). Thermolysis of 1 results in the irreversible
formation of 2. The reactivity of 2 was studied. Thus, hydrogenation of 2b furnishes the
two cluster compounds (C5Me5)WRu5(µ6-C)(µ-CCH2Ph)(µ-H)2(CO)13 (3) and (C5Me5)WRu5(µ4-
C)(µ3-CCH2Ph)(µ-H)4(CO)12 (4), generated via 1,1-addition of H2 to the ligated acetylide and
concurrent formation of two or four bridging hydrides. Treatment of 3 with CO gives the
octahedral cluster (C5Me5)WRu5(µ6-C)(µ-CCH2Ph)(CO)14 (5). The spectral and structural
properties of all species are presented and discussed.
There is a great deal of research focusing on struc-
tural and reactivity studies of high-nuclearity metal
carbido clusters.1 This is due to the belief that the
production of metal carbido intermediates is an impor-
tant initiation step in the Fischer-Tropsch catalytic
processes.2 Recently, investigation of the chemistry of
metal carbido clusters has become a rapidly expanding
reseach domain, as the interstitial carbido carbon tends
to confer high stability to the cluster, so that the
skeleton can sustain the severe reaction conditions
employed.3 As a result, many methods of building the
metal framework around the carbide atom have been
established,4 and the reactivity of these carbide clusters
with both organic and organometallic substrates has
also been studied in attempts to extend the scope of this
area.5
We surmised that the square-pyramidal cluster Ru5(µ5-
C)(CO)15 might also be an ideal precursor for the
purpose of building larger carbido clusters, because the
pyramidal core can undergo rearrangement by edge
cleavage to afford bridged-butterfly species on reactions
with donor molecules.7 The subsequent removal of a
CO ligand results in the regeneration of the original
square-pyramidal framework. Therefore, this reversible
rearrangement is useful in designing new strategies for
the incorporation of additional heterometal fragments.
In this paper we report studies on the reactions of
Ru5(µ5-C)(CO)15 with the tungsten acetylide complexes
LW(CO)3(CCPh) (L ) Cp, C5Me5) to form the octahedral
WRu5 carbido cluster derivatives. It appears that the
building of the cluster framework, which occurs via the
initial coordination of the acetylide C-C multiple bond
to the Ru5 platform, proceeds via a rearrangement
similar to the process described above.
Parallel to this research direction, Shriver and co-
workers have reported seminal work using ketenylidene
complexes to synthesize a variety of carbido clusters.6
(4) (a) Henly, T. J .; Shapley, J . R.; Rheingold, A. L.; Geib, S. J .
Organometallics 1988, 7, 441. (b) Bailey, P. J .; Blake, A. J .; Dyson, P.
J .; J ohnson, B. F. G.; Lewis, J .; Parisini, E. J . Organomet. Chem. 1993,
452, 175. (c) Fumagalli, A.; Martinengo, S.; Albano, V. G.; Braga, D.;
Grepioni, F. J . Chem. Soc., Dalton Trans. 1993, 2047. (d) Adatia, T.;
Curtis, H.; J ohnson, B. F. G.; Lewis, J .; McPartlin, M.; Morris, J . J .
Chem. Soc., Dalton Trans. 1994, 1109. (e) J ohnson, B. F. G.; Lewis,
J .; Curtis, H.; Adatia, T.; McPartlin, M.; Morris, J . J . Chem. Soc.,
Dalton Trans. 1994, 243. (f) Ralph, S. F.; Simerly, S. W.; Shapley, J .
R. Inorg. Chim. Acta 1995, 240, 615.
(5) (a) Braga, D.; Sabatino, P.; Dyson, P. J .; Blake, A. J .; J ohnson,
B. F. G. J . Chem. Soc., Dalton Trans. 1994, 393. (b) Adams, R. D.;
Falloon, S. B.; McBride, K. T. Organometallics 1994, 13, 4870. (c) Hsu,
G.; Wilson, S. R.; Shapley, J . R. Organometallics 1994, 13, 4159. (d)
Chihara, T.; Yamazaki, H. J . Chem. Soc., Dalton Trans. 1995, 1369.
(6) (a) Kolis, J . W.; Holt, E. M.; Hriljac, J . A.; Shriver, D. F.
Organometallics 1984, 3, 496. (b) Hriljac, J . A.; Swepston, P. N.;
Shriver, D. F. Organometallics 1985, 4, 158. (c) Hirljac, J . A.; Holt, E.
M.; Shriver, D. F. Inorg. Chem. 1987, 26, 2943. (d) J ensen, M. P.;
Henderson, W.; J ohnston, D. H.; Sabat, M.; Shriver, D. F. J . Organo-
met. Chem. 1990, 394, 121. (e) Karet, G. B.; Espe, R. L.; Stern, C. L.;
Shriver, D. F. Inorg. Chem. 1992, 31, 2658.
† National Tsing Hua University.
‡ The University of Glasgow.
X Abstract published in Advance ACS Abstracts, J une 15, 1997.
(1) (a) Horwitz, C. P.; Shriver, D. F. Adv. Organomet. Chem. 1984,
23, 219. (b) Chisholm, M. H.; Hammond, C. E.; J ohnston, V. J .; Streib,
W. E.; Huffman, J . C. J . Am. Chem. Soc. 1992, 114, 7056. (c) Dyson,
P. J .; J ohnson, B. F. G.; Lewis, J .; Martinelli, M.; Braga, D.; Grepioni,
F. J . Am. Chem. Soc. 1993, 115, 9062. (d) Bailey, P. J .; J ohnson, B. F.
G.; Lewis, J . Inorg. Chim. Acta 1994, 227, 197. (e) Ma, L.; Wilson, S.
R.; Shapley, J . R. J . Am. Chem. Soc. 1994, 116, 787. (f) Adams, R. D.;
Layland, R.; McBride, K. Organometallics 1996, 15, 5425. (g) Su, C.-
J .; Su, P.-C.; Chi, Y.; Peng, S.-M.; Lee, G.-H. J . Am. Chem. Soc. 1996,
118, 3289.
(2) (a) Wijeyesekara, S. D.; Hoffmann, R. Organometallics 1984, 3,
949. (b) Chisholm, M. H.; Clark, D. L.; Huffman, J . C.; Smith, C. A.
Organometallics 1987, 6, 1280. (c) Halet, J .-F.; Evans, D. G.; Mingos,
D. M. P. J . Am. Chem. Soc. 1988, 110, 87. (d) Shriver, D. F. J . Cluster
Sci. 1992, 3, 459.
(3) (a) Adams, R. D.; Wu, W. Organometallics 1993, 12, 1238. (b)
Haggitt, J . L.; J ohnson, B. F. G.; Blake, A. J .; Parsons, S. J . Chem.
Soc., Chem. Commun. 1995, 1263. (c) Izumi, Y.; Chihara, T.; Yamazaki,
H.; Iwasawa, Y. J . Am. Chem. Soc. 1993, 115, 6462. (d) Adams, R. D.;
Wu, W. Organometallics 1993, 12, 1243.
(7) J ohnson, B. F. G.; Lewis, J .; Nicholls, N. J .; Puga, J .; Raithby,
P. R.; Rosales, M. J .; McPartlin, M.; Clegg, W. J . Chem. Soc., Dalton
Trans. 1983, 277.
S0276-7333(97)00211-2 CCC: $14.00 © 1997 American Chemical Society

3524 Organometallics, Vol. 16, No. 15, 1997
Chao et al.
solution (30 mL) of Ru5(µ5-C)(CO)15 (100 mg, 0.106 mmol) over
30 min. After the addition of Me3NO was completed, the
solution faded from dark red to light red. The solvents were
removed under vacuum, the acetylide complex (C5Me5)W(CO)3-
(CCPh) (40 mg, 0.079 mmol) was added, and the mixture was
taken up in 30 mL of CH2Cl2. The solution was stirred at room
temperature for 10 min, during which time the color changed
to dark red. The solvent was removed, and the residue was
redissolved in the minimum amount of CH2Cl2 and separated
by thin-layer chromatography. Development with a 1:2 mix-
ture of dichloromethane and hexane produced two bands,
which were extracted from silica gel to yield 28 mg of brown
(C5Me5)WRu5(µ5-C)(CCPh)(CO)15 (1b; 0.020 mmol, 35%) and
3.4 mg of dark green (C5Me5)WRu5(µ5-C)(CCPh)(CO)13 (2b;
0.0026 mmol, 5%) in the order of elution.
Exp er im en ta l Section
Gen er a l In for m a tion a n d Ma ter ia ls. Infrared spectra
were recorded on a Perkin-Elmer 2000 FT-IR spectrometer.
1H and 13C NMR spectra were recorded on a Bruker AM-400
(400.13 MHz) or a Bruker AMX-300 (300.6 MHz) instrument.
Mass spectra were obtained on a J EOL HX110 instrument
operating in the fast atom bombardment mode (FAB). The
Ru5(µ5-C)(CO)15 carbido cluster was prepared using published
procedures.8 All reactions were performed under a nitrogen
atmosphere using solvents dried with an appropriate reagent.
Reactions were monitored by analytical thin-layer chroma-
tography (5735 Kieselgel 60 F254, E. Merck), and products
were separated on commercially available preparative thin-
layer chromatographic plates (Kieselgel 60 F254, E. Merck).
Elemental analyses were performed at the NSC Regional
Instrumentation Center at National Cheng Kung University,
Tainan, Taiwan.
Spectral data for 1b: MS spectrum (FAB, 102Ru, 184W) m/z
1362 (M+). IR (C6H12) ν(CO) 2083 (m), 2051 (s), 2035 (vs), 2029
(vs), 2015 (w), 2008 (w), 1993 (w), 1975 (w), 1970 (w), 1960
(w), 1932 (br, w) cm-1; 1H NMR (CD2Cl2, 294 K) δ 7.23 (t, 2H,
Rea ction of Ru 5(µ5-C)(CO)15 w ith Cp W(CO)3(CCP h ).
An acetonitrile solution (10 mL) of freshly sublimed Me3NO
(17.6 mg, 0.235 mmol) was added dropwise to a CH2Cl2
solution (30 mL) of Ru5(µ5-C)(CO)15 (100 mg, 0.106 mmol) over
J HH ) 7.0 Hz), 7.12 (t, 1H, J HH ) 7.0 Hz), 6.99 (d, 2H, J HH
)
7.0 Hz), 2.38 (s, 15H); 13C NMR (THF-d8, 313 K) δ 412.8 (µ5-
C), 217.9 (J WC ) 155 Hz, CO), 217.7 (J WC ) 176 Hz, CO), 208.6
(J WC ) 125 Hz, CCPh), 203.9 (CO), 202.6 (CO), 202.4 (2CO),
200.7 (CO), 200.0 (CO), 195.6 (3CO, br), 190.5 (CCPh), 145.1
(i C6H5), 129.9 (o,m C6H5), 129.0 (m,o C6H5), 127.6 (p C6H5),
104.5 (C5Me5), 11.8 (5Me). Anal. Calcd for C34H20O15Ru5W:
C, 30.08; H, 1.48. Found: C, 29.23; H, 1.56.
a
period of 30 min. After the addition of Me3NO was
completed, the color of solution faded from dark red to light
red. The solvents were removed under vacuum, the acetylide
complex CpW(CO)3(CCPh) (40 mg, 0.092 mmol) was added,
and the mixture was redissolved in 30 mL of CH2Cl2. The
solution was stirred at room temperature for 30 min until the
color changed back to dark red. The solution was concentrated
and separated by thin-layer chromatography. Development
with a 1:2 mixture of dichloromethane and hexane produced
two bands, which were extracted from silica gel to yield 24
mg of brown CpWRu5(µ5-C)(CCPh)(CO)15 (1a ; 0.018 mmol,
28%) and 2.7 mg of dark green CpWRu5(µ5-C)(CCPh)(CO)13
(2a ; 0.002 mmol, 3%) in order of elution.
Spectral data for 2b: MS spectrum (FAB, 102Ru, 184W), m/z
1306 (M+); IR (C6H12) ν(CO) 2071 (m), 2033 (vs), 2028 (s), 2012
(s), 1985 (w), 1975 (w), 1967 (vw), 1880 (vw, br), 1794 (w) cm-1
;
1H NMR (CD2Cl2, 294 K) δ 7.35-7.25 (m, 5H), 2.27 (s, 15H);
13C NMR (THF-d8, 294 K) δ 418.0 (µ5-C), 256.8 (µ-CO), 204.7
(CO), 203.8 (CO), 203.3 (CO), 202.3 (3CO), 198.5 (CO), 195.1
(CO), 194.6 (CO), 183.1 (CCPh), 138.8 (CCPh), 138.0 (i C6H5),
132.4 (o,m C6H5), 131.7 (p C6H5), 131.1 (m,o C6H5), 113.7
(C5Me5), 14.3 (5Me). Anal. Calcd for C32H20O13Ru5W: C,
29.53; H, 1.55. Found: C, 29.09; H, 1.60.
Spectral data for 1a : MS spectrum (FAB, 102Ru, 184W) m/z
1292 (M+); IR (C6H12) ν(CO) 2086 (m), 2052 (s), 2039 (s), 2033
(vs), 2018 (vw), 2011 (w), 1997 (w), 1984 (vw), 1976 (vw), 1970
Th er m olysis of (C5Me5)WRu 5(µ5-C)(CCP h )(CO)15
. A
1
(vw), 1948 (vw), 1931 (w), 1909 (vw) cm-1; H NMR (CD2Cl2,
toluene solution (30 mL) of 1b (50 mg, 0.037 mmol) was stirred
at reflux for 5 h, during which time the color changed from
brown to dark green. The solvent was removed in vacuo, and
the residue was taken up in CH2Cl2 and separated by thin-
layer chromatography (1:3 dichloromethane-hexane), afford-
ing 39 mg of 2b (0.030 mmol, 81%).
294 K) δ 7.15 (t, 2H, J HH ) 7.0 Hz), 7.04 (t, 1H, J HH ) 7.0 Hz),
6.88 (d, 2H, J HH ) 7.0 Hz), 5.89 (s, 5H); 13C NMR (CD2Cl2,
294 K) δ 412.7 (µ5-C), 216.0 (J WC ) 155 Hz, CO), 213.6 (J WC
)
176 Hz, CO), 206.4 (J WC ) 124 Hz, CCPh), 203.5 (CO), 203.4
(CO), 202.3 (CO), 201.5 (CO), 201.0 (CO), 200.0 (CO), 199.1
(CO), 196.7 (3CO, br), 190.4 (CCPh), 147.2 (i C6H5), 131.2 (o,m
C6H5), 130.3 (m,o C6H5), 129.0 (p C6H5), 90.8 (C5H5). Anal.
Calcd for C29H10O15Ru5W: C, 27.05; H, 0.78. Found: C, 26.99;
H, 0.83.
Hyd r ogen a tion of (C5Me5)WRu 5(µ5-C)(CCP h )(CO)13. A
toluene solution (30 mL) of 2b (50 mg, 0.038 mmol) was heated
at 80 °C under an H2 atmosphere for 3 h, during which time
the color changed from dark green to brown. After removal
of solvent, the residue was redissolved in CH2Cl2 and separated
by thin-layer chromatography (1:2 dichloromethane-hexane),
affording 23 mg of (C5Me5)WRu5(µ6-C)(µ-CCH2Ph)(µ-H)2(CO)13
(3; 0.022 mmol, 45%) and 14 mg of (C5Me5)WRu5(µ4-C)(µ3-
CCH2Ph)(µ-H)4(CO)12 (4; 0.011 mmol, 28%).
Spectral data for 2a : MS spectrum (FAB, 102Ru, 184W) m/z
1236 (M+); IR (C6H12) ν(CO) 2075 (m), 2037 (vs), 2017 (s), 1999
(vw), 1988 (vw), 1984 (w), 1877 (vw, br), 1808 (w) cm-1 1H
;
NMR (CDCl3, 294 K) δ 7.27-7.23 (m, 5H), 5.87 (s, 5H); 13C
NMR (CDCl3, 294 K) δ 411.4 (J WC ) 94 Hz, µ5-C), 251.7 (J WC
) 82 Hz, µ-CO), 201.7 (CO), 200.7 (CO), 200.6 (CO), 197.8
(3CO), 196.1 (CO, br), 192.6 (CO, br), 192.2 (CO), 178.2 (J WC
) 140 Hz, CCPh), 134.8 (i C6H5), 133.7 (CCPh), 130.6 (o,m
C6H5), 129.7 (p C6H5), 129.0 (m,o C6H5), 95.4 (C5H5). Anal.
Calcd for C27H10O13Ru5W: C, 26.33; H, 0.82. Found: C, 26.40;
H, 1.05.
Spectral data for 3: MS spectrum (FAB, 102Ru, 184W) m/z
1310 (M+); IR (C6H12) ν(CO) 2073 (m), 2046 (m), 2032 (vs), 2026
(s), 2010 (m), 1984 (br, vw), 1964 (br, vw), 1892 (br, w), 1853
(br, w) cm-1 1H NMR (CDCl3, 294 K) δ 7.24-7.21 (m, 3H),
;
6.65-6.61 (m, 2H), 4.10 (s, 2H, CH2), 2.43 (s, 15H), -17.15 (s,
2H, J WH ) 76 Hz); 13C NMR (CDCl3, 294 K) δ 421.9 (µ6-C),
338.3 (µ3-CCH2Ph), 235.8 (2CO), 219.5 (CO), 210.1 (3CO), 202.9
(CO), 198.1 (2CO), 196.4 (4CO), 137.9 (i C6H5), 129.3 (o,m
C6H5), 127.8 (p C6H5), 127.5 (m,o C6H5), 105.7 (C5Me5), 63.4
(CH2), 14.1 (Me). Anal. Calcd for C32H24O13Ru5W: C, 29.44;
H, 1.85. Found: C, 29.23; H, 1.56.
Spectral data for 4: MS spectrum (FAB, 102Ru, 184W) m/z
1284 (M+); IR (C6H12) ν(CO) 2091 (m), 2066 (s), 2032 (vs), 2018
(s), 2013 (m), 2002 (m), 1992 (m), 1973 (w), 1957 (vw), 1929
(w), 1880 (br, vw), 1794 (vw) cm-1; 1H NMR (CDCl3, 294 K) δ
7.43 (d, 2H, J HH ) 7.3 Hz), 7.36 (t, 2H, J HH ) 7.3 Hz), 7.27 (t,
1H, J HH ) 7.3 Hz), 5.08 (d, 1H, CH2, J HH ) 16.2 Hz), 4.28 (d,
Th er m olysis of Cp WRu 5(µ5-C)(CCP h )(CO)15. A toluene
solution (20 mL) of CpWRu5(µ5-C)(CCPh)(CO)15 (22 mg, 0.017
mmol) was stirred at reflux temperature for 70 min, during
which time the color changed from brown to dark green. After
solvent was removed in vacuo, the residue was taken up in
CH2Cl2 and separated by thin-layer chromatography (1:2
dichloromethane-hexane), affording 17 mg of CpWRu5(µ5-C)-
(CCPh)(CO)13 (0.013 mmol, 78%) as the only isolable product.
Reaction of Ru 5(µ5-C)(CO)15 with (C5Me5)W(CO)3(CCP h ).
An acetonitrile solution (10 mL) of freshly sublimed Me3NO
(17.6 mg, 0.235 mmol) was added dropwise into a CH2Cl2
1H, CH2, J HH ) 16.2 Hz), 2.19 (s, 15H), -13.58 (d, 1H, J HH
2.0 Hz), -13.90 (s, 1H, J WH ) 83 Hz), -14.73 (d, 1H, J HH
)
)
(8) Nicholls, J . N.; Vargas, M. D. Inorg. Synth. 1989, 26, 280.

WRu5 Carbido Clusters Bearing Acetylide Ligands
Organometallics, Vol. 16, No. 15, 1997 3525
Ta ble 1. X-r a y Str u ctu r a l Da ta of Com p lexes 1a , 2a , 3, a n d 4
1a
2a
3
4
formula
mol wt
C30H12Cl2O15Ru5W
1372.50
C27H10O13Ru5W
1231.55
C32H22O13Ru5W
1303.7
C31H22O12Ru5W
1275.7
cryst syst
space group
a (Å)
b (Å)
c (Å)
orthorhombic
Pbca
12.361(2)
18.833(1)
31.887(4)
monoclinic
P21/ n
11.0988(7)
16.038(1)
17.335(1)
monoclinic
P21/c
21.8452(2)
18.4710(1)
18.4647(2)
triclinic
P1h
10.6645(2)
19.1823(4)
20.0186(4)
102.794(1)
99.908(1)
94.378(1)
3906(1)
R (deg)
â (deg)
90.847(5)
99.039(1)
γ (deg)
V (Å3)
7423(1)
3085.3(4)
7358(1)
Z
8
4
8
4
Dc (g/cm3)
F(000)
2.456
5120
2.651
2280
2.354
4896
2.169
2392
instrument
2θ(max) (deg)
hkl ranges
Enraf-Nonius CAD4
47.3
-13 to 0, 0-21,
-35 to 0
0.53 × 0.27 × 0.10
52.80
1.00, 0.506
5579
457
Enraf-Nonius CAD4
50
Siemens SMART CCD
51.4
-22 to +25, -21 to +22,
-19 to +21
0.41 × 0.10 × 0.05
51.76
0.957, 0.634
7976 with I g 3σ(I)
920
Siemens SMART CCD
51.2
-12 to +12, -23 to +23,
-24 to +23
0.09 × 0.11 × 0.31
48.71
0.962, 0.556
8906 with I g 3σ(I)
883
-13 to +13, 0-19,
0-20
cryst size (mm)
0.40 × 0.33 × 0.20
61.63
µ(Mo KR) (cm-1
)
transmissn: max, min
no. of data in refinement
no. of params
0.696, 0.488
5413
395
max ∆/σ ratio
0.068
0.034; 0.071
1.02
0.001
0.024; 0.058
1.047
0.001
0.050; 0.043
1.37
0.0001
0.059; 0.069
1.57
RF; Rw
GOF
D map, max/min (e/Å3)
+1.15/-1.31
+0.79/-0.62
+1.13/-1.28
+4.34/-1.44
Ta ble 2. Selected Bon d Dista n ces (Å) a n d Bon d
An gles (d eg) of 1a (Esd ’s in P a r en th eses)
2.0 Hz), -23.40 (s, 1H); 13C NMR (CDCl3, 294 K) δ 380.7 (µ4-
C, J WC ) 114 Hz), 325.0 (µ3-CCH2Ph, J WC ) 126 Hz), 198.1
(CO), 197.2 (CO), 196.5 (CO), 194.0 (2CO), 193.3 (CO), 192.0
(CO), 190.6 (CO), 188.8 (3CO), 186.8 (CO), 146.1 (i C6H5), 130.7
(o,m C6H5), 128.3 (m,o C6H5), 126.7 (p C6H5), 106.5 (C5Me5),
65.5 (CH2Ph), 12.1 (5Me). Anal. Calcd for C31H26O12Ru5W:
C, 29.14; H, 2.05. Found: C, 29.05; H, 2.11.
W(1)-Ru(1)
Ru(1)-Ru(2)
Ru(1)-Ru(5)
Ru(2)-Ru(4)
Ru(4)-Ru(5)
Ru(1)-C(1)
Ru(3)-C(2)
C(1)-C(2)
2.9113(8)
2.851(1)
2.7431(9)
2.871(1)
2.945(1)
2.145(8)
2.208(8)
1.34(1)
W(1)-Ru(5)
Ru(1)-Ru(3)
Ru(2)-Ru(3)
Ru(3)-Ru(4)
W(1)-C(1)
Ru(5)-C(1)
Ru(5)-C(2)
Ru(1)-C(5)
Ru(3)-C(5)
Ru(5)-C(5)
Ru(3)-C(31)
2.9000(8)
2.806(1)
2.845(1)
2.814(1)
2.019(8)
2.165(8)
2.371(8)
1.955(8)
2.125(8)
2.061(8)
1.95(1)
Rea ction of (C5Me5)WRu 5(µ6-C)(µ-CCH2P h )(µ-H)2(CO)13
w ith CO. A toluene solution (20 mL) of 3 (52 mg, 0.039 mmol)
was heated at reflux under a CO atmosphere for 45 min. After
removal of solvent, the residue was redissolved in CH2Cl2 and
separated by thin-layer chromatography (1:3 dichloromethane-
hexane), affording 21 mg of (C5Me5)WRu5(µ6-C)(µ-CCH2Ph)-
(CO)14 (5; 0.016 mmol, 40%).
Ru(2)-C(5)
Ru(4)-C(5)
Ru(2)-C(31)
2.037(8)
1.986(8)
2.55(1)
W(1)-C(1)-C(2) 152.5(6)
C(1)-C(2)-C(111) 125.1(7)
Spectral data for 5: MS spectrum (FAB, 102Ru, 184W) m/z
1336 (M+); IR (C6H12) ν(CO) 2073 (m), 2041 (s), 2028 (vs), 2009
(m), 1980 (w), 1971 (w), 1962 (vw), 1887 (br, w), 1842 (br, w),
factors embedded in the SHELXL93 program were used, with
corrections applied for anomalous dispersion.
Crystal data for complexes 3 and 4 were collected on a
Siemens Smart-CCD diffractometer equipped with a normal-
focus, 3 kW sealed-tube X-ray source. Unit cell dimensions
were determined by collecting reflections within angles 5° <
2θ < 50°, followed by spot integration and least-squares
refinement. Data were collected in frames with increasing ω
(0.30° per frame) and with the scan speed at 10.0 s per frame.
Frame data were integrated using the SAINT program.
Absorption correction was performed using the XPREP pro-
gram.11 The structures of 3 and 4 were solved by using the
SHELXTL-PC package and refined by block-matrix and full-
matrix least squares, respectively. All non-hydrogen atoms
were given anisotropic thermal parameters, while hydrogen
atoms were placed in idealized positions with fixed isotropic
temperature factors.
1
1781 (w) cm-1; H NMR (CDCl3, 294 K) δ 7.32-7.23 (m, 3H),
6.96-6.90 (m, 2H), 3.95 (s, 2H, CH2), 2.37 (s, 15H); 13C NMR
(CDCl3, 294 K) δ 137.8 (i C6H5), 129.4 (o,m C6H5), 128.8 (m,o
C6H5), 127.8 (p C6H5), 107.9 (C5Me5), 64.6 (CH2Ph), 13.2 (5Me).
Anal. Calcd for C33H22O14Ru5W: C, 29.76; H, 1.67. Found:
C, 29.82; H, 1.74.
X-r a y Cr ysta llogr a p h y. Diffraction measurements on
complexes 1a and 2a were carried out on an Enraf-Nonius
Turbo CAD-4 diffractometer, running under CAD4-Express
software. Unit cell dimensions were determined by refinement
of the setting angles of 25 optimal high-angle reflections, which
were flagged during data collection. Standard reflections were
measured every 2 h during data collection. Decay in intensi-
ties was noted for both complexes, and an interpolated
correction was applied. All reflections were corrected for
Lorentz, polarization, and absorption effects. The structures
were solved by direct methods (SIR92)9 for all non-hydrogen
atoms. The non-hydrogen atoms were allowed anisotropic
thermal motion. Hydrogen atoms were placed in calculated
positions with C-H ) 0.96 Å. An extinction correction was
then applied. Refinement was by full-matrix least squares
using the program SHELXL93.10 The neutral atom scattering
The crystallographic refinement parameters of complexes
1a , 2a , 3, and 4 are given in Table 1, while their selected bond
distances and angles are presented in Tables 2-5, respectively.
Resu lts
Syn th esis a n d Ch a r a cter iza tion of 1 a n d 2. The
carbido cluster Ru5(µ5-C)(CO)15 reacts with 2 equiv of
the oxidative decarbonylation reagent Me3NO in aceto-
nitrile solution at room temperature to afford an un-
(9) Altomare, A.; Cascarno, G.; Giacovazzo, C.; Gualiardi, A. J . Appl.
Crystallogr. 1994, 27, 435.
(10) A program for crystal structure refinement: Sheldrick, G. M.,
University of Go¨ttingen, Go¨ttingen, Germany, 1993.
(11) Sheldrick, G. M. SHELXTL PC, version 5; Siemens Analytical
X-ray Instruments, Madison, WI, 1994.

3526 Organometallics, Vol. 16, No. 15, 1997
Chao et al.
Ta ble 3. Selected Bon d Dista n ces (Å) a n d Bon d
An gles (d eg) of 2a (Esd ’s in P a r en th eses)
W(1)-Ru(2)
W(1)-Ru(5)
Ru(2)-Ru(3)
Ru(2)-Ru(5)
Ru(3)-Ru(4)
Ru(4)-Ru(5)
Ru(2)-C(1)
Ru(2)-C(2)
C(1)-C(2)
2.7841(4)
2.9780(5)
2.8534(6)
2.6958(6)
2.8185(6)
2.6623(6)
2.203(5)
2.270(5)
1.347(7)
2.178(5)
2.057(5)
W(1)-Ru(4)
W(1)-Ru(6)
Ru(2)-Ru(4)
Ru(2)-Ru(6)
Ru(3)-Ru(6)
W(1)-C(1)
Ru(5)-C(1)
Ru(5)-C(2)
W(1)-C
2.9735(5)
2.8685(5)
2.7953(6)
2.8535(6)
2.8319(6)
1.950(5)
2.181(5)
2.100(5)
2.026(5)
2.020(5)
2.073(5)
Ru(2)-C
Ru(3)-C
Ru(4)-C
Ru(6)-C
W(1)-C(1)-C(2) 154.2(4)
C(1)-C(2)-C(111) 138.2(4)
Ta ble 4. Selected Bon d Dista n ces (Å) a n d Bon d
An gles (d eg) of 3 (Esd ’s in P a r en th eses)
W(1)-Ru(1)
W(1)-Ru(3)
Ru(1)-Ru(2)
Ru(1)-Ru(5)
Ru(2)-Ru(4)
Ru(3)-Ru(5)
W(1)-C(14)
Ru(2)-C(14)
Ru(4)-C(14)
W(1)-C(15)
3.216(1)
2.872(1)
2.929(2)
2.898(2)
2.861(2)
2.894(2)
2.11(1)
2.08(1)
2.09(1)
1.90(2)
W(1)-Ru(2)
W(1)-Ru(5)
Ru(1)-Ru(4)
Ru(2)-Ru(3)
Ru(3)-Ru(4)
Ru(4)-Ru(5)
Ru(1)-C(14)
Ru(3)-C(14)
Ru(5)-C(14)
Ru(3)-C(15)
3.039(1)
3.015(1)
2.816(2)
2.895(2)
2.785(2)
2.858(1)
2.01(1)
2.08(1)
2.06(1)
2.19(1)
F igu r e 1. Molecular structure and atomic labeling scheme
of the complex CpWRu5(µ5-C)(CCPh)(CO)15 (1a ), with
thermal ellipsoids shown at the 30% probability level.
pairs of carbido cluster complexes were fully character-
ized by spectroscopic methods and, for the Cp deriva-
tives 1a and 1b, by single-crystal X-ray diffraction
studies.
W-C(15)-Ru(3)
Ru(3)-C(15)-C(16) 120.4(11) C(15)-C(16)-C(17) 114.0(13)
88.8(5)
W(1)-C(15)-C(16) 150.5(11)
Ta ble 5. Selected Bon d Dista n ces (Å) a n d Bon d
An gles (d eg) of 4 (Esd ’s in P a r en th eses)
The molecular geometry established for complex 1a
is shown in Figure 1 together with the atomic number-
ing scheme. Select bond angles and distances are
presented in Table 2. The Ru5 metal fragment forms a
wingtip-bridged butterfly or a distorted square-base-
pyramidal geometry, where the Ru(3)-Ru(5) bond is too
long to be considered bonding (3.367(1) Å), which is
similar to what is observed in several Ru5(µ5-C) and
Os5(µ5-C) derivatives.13,14 The Ru(1)-Ru(5) edge is
symmetrically bridged by the W atom. The carbide
carbon C(5) is almost coplanar, with the best plane
defined by atoms Ru(1), Ru(2), Ru(3), and Ru(5), and is
displaced by 0.056(8) Å toward the apical atom Ru(3).
All carbonyl ligands apart from the unique CO(31)
ligand are terminally bonded, the latter being very
asymmetrically linked to the Ru(2)-Ru(3) hinge. The
metal-metal distances are in the range 2.7431(9)-
2.945(1) Å, with the W-Ru bonds being slightly longer
than the Ru-Ru bond. The shortest Ru-Ru bond
length of 2.7431(9) Å is that assigned to the Ru-Ru
vector bridged by the unique CpW(CO)2 vertex. The
acetylide ligand, which adopts a µ4-η2 bonding mode,
resides above the W(1)-Ru(1)-Ru(5) triangle (W(1)-
C(1) ) 2.019(8) Å, Ru(1)-C(1) ) 2.145(8) Å, and Ru(5)-
C(1) ) 2.165(8) Å), and the â-carbon is coordinated to
the Ru(3) and Ru(5) atoms (Ru(3)-C(2) ) 2.208(8) Å
and Ru(5)-C(2) ) 2.371(8) Å). The acetylide ligand in
this molecule represents an example in which the
R-carbon is linked to a triangular face on the pseudo-
spiked triangular metal arrangement (A), while the
â-carbon is coordinated to the metal pendant which is
perpendicular to the M3 face (Chart 1). In contrast,
tetranuclear metal complexes with the acetylide ligand
coordinated to M3 face via the µ3-η2( ) interaction and
W(1)-Ru(2)
W(1)-Ru(4)
Ru(1)-Ru(2)
Ru(2)-Ru(3)
Ru(2)-Ru(5)
Ru(4)-Ru(5)
Ru(1)-C(13)
Ru(5)-C(13)
Ru(4)-C(14)
C(14)-C(15)
2.880(1)
2.873(1)
2.908(2)
2.798(2)
2.924(1)
2.773(1)
2.04(1)
2.18(2)
2.13(1)
1.50(2)
W(1)-Ru(3)
W(1)-Ru(5)
Ru(1)-Ru(5)
Ru(2)-Ru(4)
Ru(3)-Ru(4)
W(1)-C(13)
Ru(2)-C(13)
W(1)-C(14)
Ru(5)-C(14)
3.078(1)
2.849(1)
2.880(2)
2.986(2)
2.673(2)
1.91(1)
2.12(1)
2.01(2)
2.17(2)
W(1)-C(13)-Ru(1) 174.0(9)
Ru(2)-C(13)-Ru(5) 85.6(5)
stable light red complex which is tentatively assigned
to have the empirical formula Ru5(µ5-C)(CO)13(NCMe)2.12
It is also possible that this uncharacterized intermediate
adopts an alternative edge-bridged butterfly geometry
with the formula Ru5(µ5-C)(CO)13(NCMe)3. This is due
to the fact that dissolution of the parent carbido cluster
Ru5(µ5-C)(CO)15 in acetonitrile results in the instanta-
neous formation of the cluster Ru5(µ5-C)(CO)15(NCMe).13
Thus, the further addition of 2 equiv of Me3NO would
replace two more CO ligands, affording the proposed
Ru5(µ5-C)(CO)13(NCMe)3. No attempt was made to
isolate and characterize this unstable material.
However, upon the addition of excess tungsten acetyl-
ide complex CpW(CO)3(CCPh) to this solution, the two
heterometallic clusters CpWRu5(µ5-C)(CCPh)(CO)15 (1a )
and CpWRu5(µ5-C)(CCPh)(CO)13 (2a ) were generated in
moderate yields. The reaction of Ru5(µ5-C)(CO)15 with
Me3NO and (C5Me5)W(CO)3(CCPh) afforded the corre-
sponding complexes (C5Me5)WRu5(µ5-C)(CCPh)(CO)15
(1b ) and (C5Me5)WRu5(µ5-C)(CCPh)(CO)13 (2b ) under
similar conditions. Complexes 1 appear to be the
precursors, because thermolysis of 1 afforded the re-
spective complexes 2a and 2b in high yields. These two
(12) Way, C.-J .; Chi, Y.; Mavunkal, I. J .; Wang, S.-L.; Liao, F.-L.;
Peng, S.-M.; Lee, G.-H. J . Cluster Sci. 1997, 8, 61.
(13) J ohnson, B. F. G.; Lewis, J .; Nelson, W. J . H.; Nicholls, J . N.;
Vargas, M. D. J . Organomet. Chem. 1983, 249, 255.
(14) (a) J ohnson, B. F. G.; Lewis, J .; Raithby, P. R.; Rosales, M. J .;
Welch, D. A. J . Chem. Soc., Dalton Trans. 1986, 453. (b) J ohnson, B.
F. G.; Lewis, J .; Raithby, W. P. R.; Saharan, V. P.; Wong, W. T. J .
Organomet. Chem. 1992, 434, C10.

WRu5 Carbido Clusters Bearing Acetylide Ligands
Organometallics, Vol. 16, No. 15, 1997 3527
Ch a r t 1
with the R-carbon spanning the extended metal spike
(see B) or with the acetylide coordinated to the butterfly
framework, which is represented by the structure C,
have been reported in the literature.15
The overall molecular structure of 2a is shown in
Figure 2, and the selected distances are presented in
Table 3. The cluster core is based on a WRu4 square-
pyramidal geometry, with an additional Ru atom oc-
cupying one of the WRu2 metal triangles. All metal-
metal distances are indicative of single bonds, of which
the distances (Ru(4)-Ru(5) ) 2.6623(6) Å and Ru(2)-
Ru(5) ) 2.6958(6) Å) are significantly shorter than the
remaining metal-metal separations (2.7841(4)
Å-2.9780(5) Å). This molecule possesses 13 CO ligands.
Three carbonyl ligands act as semibridging or bridging
ligands, while the remaining CO ligands are considered
terminal. The ligand CO(32) is very asymmetrically
bonded to the two Ru atom (Ru(3)-C(32) ) 1.919(7) Å
and Ru(6)-C(32) ) 2.608(7) Å), while the other two
bridging carbonyl ligands CO(42) and CO(61) are much
more symmetrical. The carbide atom resides in the
cavity of the central WRu4 square pyramid. The metal-
carbide distances are approximately equal, with W(1)-C
) 2.026(5) Å and Ru-C distances within the range
2.020(5)-2.178(6) Å, which places the carbide atom
0.292(5) Å below the square base away from the apical
site. The acetylide ligand is bonded to a WRu2 face in
the typical µ3-η2( ) fashion, similar to those detected in
trinuclear metal complexes.16
F igu r e 2. Molecular structure and atomic labeling scheme
of the complex CpWRu5(µ5-C)(CCPh)(CO)13 (2a ), with
thermal ellipsoids shown at the 30% probability level.
µ3-mode is consistent with the trend observed in the
iron-group polynuclear acetylide complexes.17
Con ver sion to Ca r bid o-Alk ylid yn e Clu ster s.
Treatment of 2 with H2 was carried out in an attempt
to study its reactivity. Reaction of 2a with H2 has failed
to provide any stable product, but the gentle heating of
2b in toluene (80 °C, 3 h) under 1 atm of H2 afforded
two hexanuclear complexes (C5Me5)WRu5(µ6-C)(µ-CCH2-
Ph)(µ-H)2(CO)13 (3, 45%) and (C5Me5)WRu5(µ4-C)(µ3-
CCH2Ph)(µ-H)4(CO)12 (4, 28%). The identification was
made using both spectroscopic and X-ray diffraction
methods. These complexes are produced by two com-
peting independent pathways, as no interconversion
between 3 and 4 was noted by heating the solution of
either 3 or 4 under nitrogen or dihydrogen or even under
a carbon monoxide atmosphere.
The 13C NMR spectra of both complexes 1 and 2 are
in good agreement with the X-ray structure established.
All these complexes exhibited a characteristic signal in
the downfield region δ 412.8-418.0, which is assigned
to the carbide carbon. The assignments for CO ligands
are deceptive, as we only observed 12 CO signals for 1
and 10 CO signals for 2, out of the expected 15 and 13
CO signals, respectively. We believe that it is due to
the rapid exchange of CO in solution. On the other
hand, the 13C NMR spectra show signals at δ 206.4 (1a )
and 208.6 (1b) for the R-carbons of the acetylide ligand
and at δ 190.4 (1a ) and 190.5 (1b) for the â-carbons,
while the corresponding signals of 2 appeared at the
high-field region of δ 178.2 (2a ) and 183.1 (2b) and δ
133.7 (2a ) and 133.8 (2b). The high-field shift of these
13C NMR signals on changing from the µ4-mode to the
For complex 3, the 1H NMR spectrum exhibits two
sharp signals at δ 4.10 and -17.15 (J WH ) 76 Hz) in
the ratio 2:2, in addition to the signals assigned to
C5Me5 and the phenyl groups, showing the presence of
two chemically equivalent hydride signals and the
conversion of the acetylide ligand CCPh into the alkyl-
idyne fragment CCH2Ph. Further evidence in favor of
this assignment is derived from the subsequent 13C
NMR study: one signal at δ 338.3 falls in the range
expected for the doubly bridging alkylidyne ligand,18
while the signals at δ 63.4 and 421.9 are assigned to
the methylene and carbide fragments, respectively.
Complex 3 was found to crystallize within an asym-
metric unit possessing two crystallographically distinct
but structurally similar molecules. A perspective view
of one of these molecules is depicted in Figure 3 (see
also Table 4 for selected bond distances). The molecule
contains a significantly distorted octahedral WRu5
cluster core, with an idealized mirror plane passing
through the metal atoms W(1), Ru(1), Ru(3), and Ru(4)
of the cluster core. The Ru(4) atom is unique, as it is
coordinated by four bridging CO ligands and one
terminal CO ligand. Each of the remaining four Ru
(15) (a) Roland, E.; Vahrenkamp, H. Organometallics 1983, 2, 1048.
(b) Weatherell, C.; Taylor, N. J .; Carty, A. J .; Sappa, E.; Tiripicchio,
A. J . Organomet. Chem. 1985, 291, C9. (c) Seyferth, D.; Hoke, J . B.;
Rheingold, A. L.; Cowie, M.; Hunter, A. D. Organometallics 1988, 7,
2163. (d) Bernhardt, W.; Vahrenkamp, H. J . Organomet. Chem. 1988,
355, 427. (e) Ewing, P.; Farrugia, L. J . Organometallics 1989, 8, 1246.
(f) Farrugia, L. J . Organometallics 1990, 9, 105. (g) Akita, M.; Terada,
M.; Tanaka, M.; Moro-oka, Y. Organometallics 1992, 11, 3468. (h) Su,
P.-C.; Chiang, S.-J .; Chang, L.-L.; Chi, Y.; Peng, S.-M.; Lee, G.-H.
Organometallics 1995, 14, 4844.
(16) (a) Sappa, E.; Tiripicchio, A.; Braunstein, P. Chem. Rev. 1983,
83, 203. (b) Hwang, D.-K.; Chi, Y.; Peng, S.-M.; Lee, G.-H. Organo-
metallics 1990, 9, 2709. (c) Sappa, E. J . Cluster Sci. 1994, 5, 211.
(17) Carty, A. J .; Cherkas, A. A.; Randall, L. H. Polyhedron 1988,
7, 1045.
(18) Chi, Y.; Shapley, J . R. Organometallics 1985, 4, 1900.

3528 Organometallics, Vol. 16, No. 15, 1997
Chao et al.
F igu r e 4. Molecular structure of Cp*WRu5(µ4-C)(µ-CCH2-
Ph)(µ-H)4(CO)12 (4), showing the atomic labeling scheme
and thermal ellipsoids at the 30% probability level.
F igu r e 3. Molecular structure of Cp*WRu5(µ6-C)(µ-CCH2-
Ph)(µ-H)2(CO)13 (3), showing the atomic labeling scheme
and thermal ellipsoids at the 30% probability level.
ening of the W(1)-carbide distance (W(1)-C(14) )
2.11(1) Å) with respect to other Ru-carbide distances
(2.01(1)-2.09(1) Å) is also subject to the same kind of
competing effect.
atoms is linked to one bridging and two terminal CO
ligands. The Ru-Ru distances span the narrow range
2.785(2)-2.929(2) Å. The W-Ru separations range
from 2.872(1) to 3.216(1) Å, with the shortest W-Ru
bond linking to a bridging alkylidyne ligand and the
longest one located opposite to the alkylidyne ligand.
The longest W-Ru distances of ∼3.2 Å for both inde-
pendent molecules indicate a rather weak metal-metal
interaction, but since the overall electron count of 86 is
normal for an octahedral cluster, this may arise from
steric factors such as the bulk of the C5Me5 ligand or
from the trans effect exerted by the bridging alkylidyne
fragment (vide infra).
The bridging hydrides of 3 are found to associate with
the W(1)-Ru(2) and W(1)-Ru(5) edges. Although these
hydride ligands were not directly observed, their posi-
tions were independently confirmed using HYDEX
potential energy calculations.23 In addition, this pro-
posal is entirely consistent with the expansion of the
W(1)-Ru-CO angles associated with these edges and
with the 1H NMR data, which show a large J WH coupling
constant for the hydride resonance at δ -17.15.
The spectroscopic and structural properties of complex
1
4 differ greatly from those of 3. The H NMR spectrum
The W(1)-C(15) distance (1.90(2) Å) of the alkylidyne
ligand is substantially shorter than the Ru(3)-C(15)
distance (2.19(1) Å), while the W(1)-C(15)-C(16) angle
(150.5(11)°) is larger than the respective Ru(3)-C(15)-
C(16) angle (120.4(11)°). These data indicate that the
alkylidyne ligand is unsymmetrically coordinated to the
W-Ru(3) edge and that a substantial WtC bonding
character is retained. The unusually short W-C sepa-
ration compares well with that in the mononuclear
alkylidyne complex CpW(CO)2(tCTol) (1.82(2) Å)19 and
the ionic carborane complex [(C2B9H9Me2)W(CO)2(tCPh)]-
[PPh4] (1.82(3)-1.84(3) Å).20 Mixed-metal complexes
with an alkylidyne ligand forming an unsymmetrical
bridge on the W-Pt, W-Rh, and W-Re edges have been
reported by Stone and co-workers21 and by us.22 In
addition, the elongation of the opposite W(1)-Ru(1)
distance seems to complement the short W-C multiple
bond and is presumably due to the poor competition for
bonding vs the bridging alkylidyne ligand. The length-
of 4 is more complicated, showing two doublets at δ 5.08
and 4.28 (2J HH ) 16.2 Hz), an indication of the formation
of a methylene fragment, and four high-field signals at
δ -13.58 (J HH ) 2.0 Hz), -13.90 (J WH ) 83 Hz), -14.73
(J HH ) 2.0 Hz), and -23.40 in the ratio 1:1:1:1, sug-
gesting the formation of four hydride ligands. From
these NMR data we can assume that one H2 molecule
is now added to the acetylide ligand to give the bridging
CCH2Ph ligand, while the other two H2 molecules are
coordinated to the cluster core, forming four inequiva-
lent hydrides. These features were confirmed by a
single-crystal X-ray diffraction study.
The metal core arrangement of 4 is based on a WRu4
trigonal-bipyramidal configuration, with the W(1) atom
occupying an equatorial position (Figure 4). The Ru(2)-
Ru(5) edge is further bridged by the Ru(1) metal atom,
giving the observed edge-bridged trigonal-bipyramidal
geometry with 12 terminal CO ligands. The alkylidyne
ligand caps a WRu2 face of the central trigonal bipyra-
mid, having a short W-C distance (2.01(2) Å) and two
longer Ru-C distances (2.13(1) and 2.17(2) Å). The
carbide is located in the butterfly cavity constituted by
the four metal atoms W(1), Ru(1), Ru(2), and Ru(5). The
M(hinge)-C(carbide) distances (Ru(2)-C(13) ) 2.12(1)
Å and Ru(5)-C(13) ) 2.18(2) Å) are slightly longer,
compared to the other M(wingtip)-C(carbide) distances
(19) Fischer, E. O.; Lindner, T. L.; Huttner, G.; Friedrich, P.; Kreissl,
F. R.; Besenhard, J . O. Chem. Ber. 1977, 110, 3397.
(20) Baumann, F. E.; Howard, J . A. K.; Musgrove, R. J .; Sherwood,
P.; Stone, F. G. A. J . Chem. Soc., Dalton Trans. 1988, 1879.
(21) (a) Byers, P. K.; Carr, N.; Stone, F. G. A. J . Organomet. Chem.
1990, 384, 315. (b) Devore, D. D.; Howard, J . A. K.; J effery, J . C.; Pilotti,
M. U.; Stone, F. G. A. J . Chem. Soc., Dalton Trans. 1989, 303. (c) Green,
M.; Howard, J . A. K.; J elfs, A. N. d. m.; Nunn, C. M.; Stone, F. G. A.
J . Chem. Soc., Dalton Trans. 1987, 2219.
(22) Peng, J .-J .; Peng, S.-M.; Lee, G.-H.; Chi, Y. Organometallics
1995, 14, 626.
(23) Orpen, A. G. J . Chem. Soc., Dalton Trans. 1980, 2509.

WRu5 Carbido Clusters Bearing Acetylide Ligands
Organometallics, Vol. 16, No. 15, 1997 3529
Sch em e 1
Sch em e 2
(W(1)-C(13) ) 1.91(1) Å and Ru(1)-C(13) ) 2.04(1) Å).
This pattern of M-C distances has been observed in
other butterfly carbide cluster complexes24 and was
described in a theoretical study.25
a µ4 to a µ3 bonding mode. Most importantly, the W
atom also exchanges position with one adjacent Ru atom
and occupies an equatorial site of the central square
pyramid. We suggest that the formation of such a
closely packed geometry in 2 results in a considerably
higher chemical stability. This is confirmed by the fact
that no regeneration of 1 was observed by treatment of
both 2a and 2b with a CO atmosphere.
Another very interesting structural feature for 4 is
the position of the hydride ligands. These four hydride
ligands were not directly located, but on the basis of
potential energy calculations using the HYDEX pro-
gram,23 we propose that they are associated with the
edges W(1)-Ru(3), Ru(1)-Ru(2), and Ru(1)-Ru(5) and
the face Ru(2)-Ru(4)-Ru(5). This proposal is consist-
1
ent with the H NMR data, which show three signals
Hydrogenation of complexes 2 was also investigated
(Scheme 2), but the results were dependent on the
ancillary ligand on the W atom. Thus, only decomposi-
tion was observed for the Cp derivative 2a . When the
C5Me5 derivative 2b was utilized as the starting mate-
rial, two cluster products, one with a µ6-carbide ligand
and the second with a µ4-carbide and four hydride
ligands, were obtained in 45% and 28% yields, respec-
tively.
The efficient formation of the bridging CCH2Ph alkyl-
idyne ligands in 3 and 4 can be compared with the
hydrogenation of butterfly acetylide complexes
LWOs3(CCR)(CO)11 (L ) Cp, C5Me5; R ) Bun, CH2OMe)
and (C5Me5)WRu3(µ-NPh)(CCPh)(CO)9, also reported by
us.27 For the WOs3 clusters, the hydrogenation reaction
afforded alkylidyne complexes LWOs3(µ3-CCH2R)(CO)11
with transfer of hydrogen atoms only to the â-carbon of
the acetylide ligand. It was speculated that these
reactions proceeded via the stepwise formation of a
dihydride-acetylide intermediate (2H + CCR), followed
by formation of a hydride-vinylidene ligand (H +
CCHR), and finally the alkylidyne ligand (µ3-CCH2R).28
No incorporation of another H2 molecule as hydrides
was detected in these cases. In contrast, hydrogenation
of the second WRu3 cluster gave the cluster compound
(C5Me5)WRu3(µ-NPh)(CHCHPh)(µ-H)2(CO)8 with the
formation of a pair of hydrides as well as one trans-
vinyl fragment, formed by 1,2-addition of H2 to the
acetylide ligand. In the present system, the formation
of 3 and 4 involves both the 1,1-addition of hydrogen to
acetylide and the generation of two or four more hydride
in the range δ -13.58 to -14.73, which may be assigned
to edge-bridging hydrides, and a lower frequency signal
at δ -23.40 ascribable to the face-bridging hydride.26
Discu ssion
As shown in Scheme 1, the combination of Ru5(µ5-
C)(CO)15 with LW(CO)3(CCPh) (L ) Cp, C5Me5) in the
presence of Me3NO at room temperature initially gave
the WRu5 complexes 1 with 15 CO ligands. It is possible
that the reaction proceeds through the coordination of
the acetylide C-C triple bond to the Ru5 framework,
which links the LW(CO)3 pendant in the vicinity of the
Ru5 framework, and then promotes the formation of two
W-Ru bonds via CO elimination. The isolation of the
alkyne complex Ru5(µ5-C)[C2(CO2Me)2](CO)15 from ad-
dition of dimethyl acetylenedicarboxylate to the parent
carbido cluster Ru5(µ5-C)(CO)15 serves as evidence in
favor of this postulate.12
Although complexes 1 are the initial products of these
cluster-building reactions, they undergo thermally in-
duced transformation to afford cluster products 2 in
refluxing toluene solution. The whole transformation
involves the elimination of two CO ligands, the forma-
tion of two new metal-metal bonds compared with the
precursors 1, and conversion of the acetylide ligand from
(24) (a) Chi, Y.; Chuang, S.-H.; Chen, B.-F.; Peng, S.-M.; Lee, G.-H.
J . Chem. Soc., Dalton Trans. 1990, 3033. (b) Gong, J .-H.; Tsay, C.-W.;
Tu, W.-C.; Chi, Y.; Peng, S.-M.; Lee, G.-H. J . Cluster Sci. 1995, 6, 289.
(c) Whitmire, K. H.; Shriver, D. F. J . Am. Chem. Soc. 1981, 103, 6754.
(d) Kolis, J . W.; Holt, E. M.; Drezdzon, M.; Whitmire, K. H.; Shriver,
D. F. J . Am. Chem. Soc. 1982, 104, 6134.
(25) Harris, S.; Bradley, J . S. Organometallics 1984, 3, 1086.
(26) (a) Freeman, M. J .; Green, M.; Orpen, A. G.; Salter, I. D.; Stone,
F. G. A. J . Chem. Soc., Chem. Commun. 1983, 1332. (b) Lin, R.-C.;
Chi, Y.; Peng, S.-M.; Lee, G.-H. Inorg. Chem. 1992, 31, 3818. (c) Adams,
R. D.; Barnard, T. S.; Li, Z.; Wu, W.; Yamamoto, J . Organometallics
1994, 13, 2357. (d) Su, C.-J .; Chi, Y.; Peng, S.-M.; Lee, G.-H. Organo-
metallics 1995, 14, 4286.
(27) (a) Chi, Y.; Hwang, D.-K.; Chen, S.-F.; Liu, L.-K. J . Chem. Soc.,
Chem. Commun. 1989, 1540. (b) Chi, Y.; Lee, G.-H.; Peng, S.-M.; Wu,
C.-H. Organometallics 1989, 8, 1574.
(28) (a) Chi, Y.; Wu, C.-H.; Peng, S.-M.; Lee, G.-H. Organometallics
1991, 10, 1676. (b) Farrugia, L. J .; MacDonald, N.; Peacock, R. D. J .
Chem. Soc., Chem. Commun. 1991, 163.

3530 Organometallics, Vol. 16, No. 15, 1997
Chao et al.
ligands, respectively. Furthermore, although both com-
plexes 3 and 4 contain hydride ligands, only the hy-
drides in 3 can be removed without inducing the
unwanted cluster fragmentation. Thus, treatment of 3
with a CO atmosphere at elevated temperature pro-
duced the new octahedral cluster compound
(C5Me5)WRu5(µ6-C)(µ-CCH2Ph)(CO)14 (5) in 40% yield,
which can react with H2 to re-form the parent WRu5
cluster compound 3 in approximately 60% yield. The
characterization of 5 was achieved by comparing the
spectroscopic data with those of the derivatives
LWRu5(µ6-C)(µ-CPh)(CO)14 (L ) Cp, C5Me5), which have
been identified by X-ray structural analysis.29
hydrides and the second possessing a µ4-carbide and
four hydride ligands. Treatment of 3 with CO removed
the hydrides and gave 5 reversibly. Thus, this sequence
of reactions has provided an alternative method to the
preparation of octahedral WRu5 carbido-alkylidyne
derivatives related to complex 5. An independent
synthesis of the phenyl derivatives has been achieved
by combining (C5Me5)WRu2(CCPh)(CO)8 and Ru3(CO)12
through the direct cleavage of an acetylide ligand.
Finally, the carbide atom of these cluster compounds
has failed to react with an acetylide ligand or hydrogen
molecules but serves as an anchor to hold together the
metal atoms. Such a pattern of reactivity is in sharp
contrast to those observed in the WOs3 system, where
the carbide has shown a higher tendency in forming
C-C bonding with ligated alkylidyne or alkyne frag-
ments.30
Su m m a r y
The mononuclear acetylide complexes CpW(CO)3-
(CCPh) and (C5Me5)W(CO)3(CCPh) were used to prepare
the WRu5 carbido-alkylidyne cluster complexes. We
have shown that the acetylide ligand can link to the Ru5
framework through its unsaturated C-C π-bonding,
followed by formation of the W-Ru linkages. The
subsequent skeletal rearrangement led to the genera-
tion of the face-bridged square-pyramidal core in 2, with
the W atom located at a basal position. This cluster
core configuration is relatively more stable compared
with the precursors 1. Conversion of an acetylide to an
alkylidyne ligand can be easily achieved through hy-
drogenation. Complexes 3 and 4 were isolated in
moderate yields: one with a µ6-carbide and two bridging
Ack n ow led gm en t. We thank the National Science
Council of the Republic of China for financial support
(Grant No. NSC 86-2113-M007-035).
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates and the corresponding anisotropic thermal pa-
rameters for complexes 1a , 2a , 3, and 4 (15 pages). Ordering
information is given on any current masthead page.
OM970211L
(30) (a) Chi, Y.; Su, P.-C.; Peng, S.-M.; Lee, G.-H. Organometallics
1995, 14, 5483. (b) Chi, Y.; Chung, C.; Chou, Y.-C.; Su, P.-C.; Chiang,
S.-J .; Peng, S.-M.; Lee, G.-H. Organometallics 1997, 16, 1702.
(29) Chiang, S.-J .; Chi, Y.; Su, P.-C.; Peng, S.-M.; Lee, G.-H. J . Am.
Chem. Soc. 1994, 116, 11181.