Alkynethiolato and alkyneselenolato ruthenium half-sandwich complexes: Synthesis, structures, and reactions with (η5-C5H5)2Zr

Article abstract of DOI:10.1021/ic010826h

Alkynethiolato and alkyneselenolato complexes of ruthenium, CpRu(PPh₃)₂(EC≡CR) (Cp = η⁵-C₅H₅; E = S, R = Ph (1a), SiMe₃ (1b), ^tBu (1c); E = Se, R = Ph (2a), SiMe₃ (2b)), were synthesized by the reactions of CpRuCl-(PPh₃)₂ with corresponding lithium alkynechalcogenolates in THF. An analogous reaction of Cp*RuCl(PEt₃)₂ (Cp* = η⁵-C₅Me₅) with LiSC≡CPh produced Cp*Ru(PEt₃)₂(SC≡CPh) (3). Complexes 1a and 2a were allowed to react in THF with Cp₂Zr , generated in situ from CP₂ZrCl₂ and 2 equiv of n-BuLi, from which the S-bridged Ru-Zr dinuclear complexes CpRu(PPh₃)(C≡CPh)(μ-S)ZrCp₂ (4a) and CpRu(PPh₃)(C≡CPh)(μ-Se)ZrCp₂ (4b) were isolated, respectively. In these complexes, C-S(Se) bond cleavage of the alkynechalcogenolate ligands was promoted by Cp₂Zr , and the Zr atom was oxidized from II to IV. Treatment of 4a and 4b in THF under 1 atm CO gave rise to CpRu(CO)(C≡CPh)(μ-E)ZrCp₂ (E = S (5a), Se (5b)), while addition of tert-butyl isocyanide to a THF solution of 4b afforded CpRu(CN^tBu)(C≡CPh)(μ-Se)ZrCp₂ (6). The crystal structures of 1a, 1c, 2a, 2b, 3, 4a, 4b, and 5b were determined by X-ray diffraction analysis.

Full text of DOI:10.1021/ic010826h

7072
Inorg. Chem. 2001, 40, 7072-7078
Alkynethiolato and Alkyneselenolato Ruthenium Half-Sandwich Complexes: Synthesis,
Structures, and Reactions with (η5-C5H5)2Zr
Yusuke Sunada,† Yuji Hayashi,† Hiroyuki Kawaguchi,‡ and Kazuyuki Tatsumi*,†
Research Center for Materials Science, and Department of Chemistry, Graduate School of Science,
Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan, and Coordination Chemistry
Laboratories, Institute for Molecular Science, Myodaiji, Okazaki 444-8595, Japan
ReceiVed August 2, 2001
Alkynethiolato and alkyneselenolato complexes of ruthenium, CpRu(PPh3)2(ECtCR) (Cp ) η5-C5H5; E ) S, R
) Ph (1a), SiMe3 (1b), tBu (1c); E ) Se, R ) Ph (2a), SiMe3 (2b)), were synthesized by the reactions of CpRuCl-
(PPh3)2 with corresponding lithium alkynechalcogenolates in THF. An analogous reaction of Cp*RuCl(PEt3)2
(Cp* ) η5-C5Me5) with LiSCtCPh produced Cp*Ru(PEt3)2(SCtCPh) (3). Complexes 1a and 2a were allowed
to react in THF with “Cp2Zr”, generated in situ from Cp2ZrCl2 and 2 equiv of n-BuLi, from which the S-bridged
Ru-Zr dinuclear complexes CpRu(PPh3)(CtCPh)(µ-S)ZrCp2 (4a) and CpRu(PPh3)(CtCPh)(µ-Se)ZrCp2 (4b)
were isolated, respectively. In these complexes, C-S(Se) bond cleavage of the alkynechalcogenolate ligands was
promoted by “Cp2Zr”, and the Zr atom was oxidized from II to IV. Treatment of 4a and 4b in THF under 1 atm
CO gave rise to CpRu(CO)(CtCPh)(µ-E)ZrCp2 (E ) S (5a), Se (5b)), while addition of tert-butyl isocyanide to
a THF solution of 4b afforded CpRu(CNtBu)(CtCPh)(µ-Se)ZrCp2 (6). The crystal structures of 1a, 1c, 2a, 2b,
3, 4a, 4b, and 5b were determined by X-ray diffraction analysis.
Introduction
tion metal fragment, viz zirconocene(II) generated in situ.3-6
Zirconocene(II), Cp2Zr, is known to activate alkynes and
alkenes, affording various metallacycles via C-C bond forming
reactions.4 The reaction between Cp2Zr(CO)2 and R2S2 has been
employed in the synthesis of thiolato complexes, Cp2Zr(SR)2
(R ) Ph, Et),5 and [Cp2Zr(µ-E)]2 (E ) S, Se) were prepared
by the reaction between Cp2Zr and elemental sulfur or sele-
nium.6 Thus, we report in this paper the preparation of a series
of ruthenium(II) alkynechalcogenolato complexes, CpRu(PPh3)2-
(ECtCR) (E ) S, R ) Ph (1a), SiMe3 (1b), tBu (1c); E ) Se,
R ) Ph (2a), SiMe3 (2b)) and Cp*Ru(PEt3)2(SCtCPh) (3). The
reactions of CpRu(PR3)2Cl with LiSCtCR′ were reported to
generate η1-(S)-alkynethiolate complexes (R ) Ph; R′ ) Ph,
SiMe3) and an η1-(C)-thioketenyl complex (R ) Me; R′ ) Ph);
their X-ray structures have not been determined.7 We also report
We recently began to investigate the chemistry of transition
metal alkynethiolato and alkyneselenolato complexes.1 Our
interest in these complexes stem primarily from the two aspects.
One is the unique ability of the ligands to be bound to a single-
or multi-metal center at both chalcogen and alkyne portions,
and a variety of unusual coordination geometries would be
created. The other aspect is that having a reactive carbon-
carbon triple bond adjacent to the chalcogen atom coordinated
at a transition metal, new types of chemical transformations
would be observed at the ligands. Previously, we reported
syntheses and reactions of alkynethiolato and alkyneselenolato
complexes of titanocene(IV) and samarocene(III). For example,
the reaction of preformed Cp2Ti(SCtCPh)2 with Ni(η4-C8H12)2
gave rise to a trinuclear cluster [Cp2Ti(µ-SCtCPh)2]2Ni having
a linear Ti2Ni spine.1 Independent from us, Delgado and Lalinde
reported the synthesis of (C5H4R′)(C5H4SiMe3)Ti(SCtCR)2 (R
) tBu, Ph; R′ ) SiMe3, PPh2), and the reactions with Mo(CO)3-
(CH3CN)3, Mo(CO)4(nbd), and M(C6F5)2(thf)2 (M ) Pd, Pt) to
afford (C5H4SiMe3)2Ti(µ-SCtCR)2MLn (MLn ) Mo(CO)4, Pd-
(C6F5)2, Pt(C6F5)2) and (C5H4SiMe3)Ti(µ-η5:κ-P-C5H4PPh2)-
(SCtCtBu)(µ-SCtCtBu)MLn (MLn ) Mo(CO)3, Pd(C6F5)2, Pt-
(C6F5)2).2 In these dinuclear structures, two metal atoms are
bridged by thiolato sulfurs, and the alkyne portion remains intact.
To develop the chemistry of heterobimetallic alkynechalco-
genolato complexes, we planned to combine late transition metal
complexes of alkynechalcogenolates and a reactive early transi-
(3) (a) Peulecke, N.; Ohff, A.; Tillack, A.; Baumann, W.; Kempe, R.;
Burlakov, V. V.; Rosenthal, U. Organometallics 1996, 15, 1340-
1344. (b) Baranger, A. M.: Bergman, R, G. J. Am. Chem. Soc. 1994,
116, 3822-3835.
(4) (a) Negishi, E.; Kondakov, D, Y.; Choueiry, D.; Kasai, K.; Takahashi,
T. J. Am. Chem. Soc. 1996, 118, 9577-9588. (b) Rosenthal, U.; Ohff,
A.; Baumann, W.; Kempe, R.; Tillack, A.; Burlakov, V. V. Angew.
Chem., Int, Ed. Engl. 1994, 33, 1605-1607. (c) Pellny, P.-M.;
Burlakov, V. V.; Baumann, W.; Spannenberg, A.; Kempe, R.;
Rosenthal, U. Organometallics 1999, 18, 2906-2909. (d) Kemp, M.
I.; Whitby, R. J.; Coote, S. J. Synthesis 1998, 552-556. (e) Takahashi,
T.; Xi, Z.; Obora, Y.; Suzuki, N. J. Am. Chem. Soc. 1995, 117, 2665-
2666. (f) Jemmis, E. D.; Giju, K. T.; J. Am. Chem. Soc. 1998, 120,
6952-6964.
(5) Fochi, G.; Guidi, G.; Floriani, C. J. Chem. Soc., Dalton Trans. 1984,
1253-1256.
* To whom correspondence should be addressed. E-mail: i45100a@
nucc.cc.nagoya-u.ac.jp. Fax: +81-52-789-2943.
† Nagoya University.
(6) (a) Erker, G.; Mu¨hlenbernd, T.; Benn, R.; Rufinska, A.; Tainturier,
B.; Gautheron, B. Organometallics 1986, 5, 1620-1625. (b) Erker,
G.; Mu¨hlenbernd, T.; Nolte, R.; Petersen, J. L.; Tainturier, B.;
Gautheron, B. J. Organomet. Chem. 1986, 314, C21 -C24.
(7) (a) Weigand, W. Z. Naturforsch., Teil B 1991, 46, 1333-1337. (b)
Weigand, W.; Robl, C. Chem. Ber. 1993, 126, 1807-1809. (c)
Weigand, W.; Weisha¨upl, M.; Robl, C. Z. Naturforsch., Teil B 1996,
51, 501-505.
‡ Institute for Molecular Science.
(1) Sugiyama, H.; Hayashi, Y.; Kawaguchi, H.; Tatsumi, K. Inorg. Chem.
1998, 17, 6773-6779.
(2) Ara, I.; Delgado, E.; Fornie´s, J.; Herna´ndez, E.; Lalinde, E.; Mansilla,
N.; Moreno, M. T. J. Chem. Soc., Dalton Trans. 1998, 3199-3208.
10.1021/ic010826h CCC: $20.00 © 2001 American Chemical Society
Published on Web 11/14/2001

Ruthenium Half-Sandwich Complexes
Inorganic Chemistry, Vol. 40, No. 27, 2001 7073
C5H5). 31P{1H} NMR (CDCl3): δ 42.5. 77Se NMR (CDCl3): δ -364
the reactions of 1a and 2a with Cp2Zr, which generated the
intriguing sulfido(selenido) bridged heterobimetallic complexes,
CpRu(PPh3)(CtCPh)(µ-E)ZrCp2 (E ) S (4a), Se (4b)). These
heterobimetallic complexes were readily transformed into CpRu-
(CO)(CtCPh)(µ-E)ZrCp2 (E ) S (5a), Se (5b)) and CpRu-
(CNtBu)(CtCPh)(µ-Se)ZrCp2 (6) by treatment with CO and
CNtBu.
2
(t, J
) 21.0 Hz). IR (Nujol mull, KBr): 2110 (s, νC≡C) cm-1
.
Se-P
Anal. Calcd for C49H40SeP2Ru: C, 67.58; H, 4.63. Found: C, 67.88;
H, 4.84.
Synthesis of CpRu(PPh3)2(SeC≡CSiMe3) (2b). Again, the proce-
dure used for the isolation of 1a was applied to the synthesis of 2b.
Thus, reaction of LiSeCtCSiMe3 (0.45 mmol) with CpRuCl(PPh3)2
(0.32 g, 0.45 mmol) in THF (40 mL) afforded 0.24 g of 2b as dark-red
1
crystals in 63% yield. H NMR (CDCl3): δ 7.16-7.28 (m, 30H, Ph),
Experimental Section
4.22 (s, 5H, C5H5), 0.24 (s, 9H, SiMe3). 31P{1H} NMR (CDCl3): δ
2
42.7. 77Se NMR (CDCl3): δ -362 (t, J
) 20.7 Hz). IR (Nujol
Se-P
General. All reactions and manipulations of air-sensitive compounds
were performed under an inert atmosphere using standard Schlenk
techniques. Solvents such as THF, toluene, diethyl ether, and hexane
were distilled from sodium/benzophenone ketyl under N2. Lithium
alkynethiolates and alkyneselenolates,1,8 CpRuCl(PPh3)2, Cp*RuCl-
(PEt3)2, and Cp2ZrCl2,9 were prepared according to the literature
procedures.
NMR spectra were recorded on a Varian INOVA 500 spectrometer
operating at 500 MHz for 1H, at 202 MHz for 31P, and at 96 MHz for
77Se. 1H NMR chemical shifts were quoted in ppm relative to the
residual protons of deuterated solvents. 31P{1H} and 77Se NMR chemical
shifts were referenced to signals of external 85% H3PO4 and Me2Se,
respectively. IR spectra were recorded on a Perkin-Elmer 2000 FT-
IR spectrometer. For UV-visible spectra, a JASCO V-500 spectrometer
was used. Elemental analyses were performed on a LECO CHNS-932
microanalyzer.
mull, KBr): 2037 (s, νC≡C) cm-1. Anal. Calcd for C46H44SiSeP2Ru:
C, 63.72; H, 5.12. Found: C, 63.35; H, 5.10.
Synthesis of Cp*Ru(PEt3)2(SC≡CPh) (3). A mixture of Cp*RuCl-
(PEt3)2 (0.20 g, 0.39 mmol) and LiSCtCPh (0.39 mmol) in THF (40
mL) was treated as described for the synthesis of 1a. The resulting
residue was recrystallized from Et2O to yield 0.23 g of 3 as orange
1
crystals (68%). H NMR (C6D6): δ 7.60 (m, 2H, Ph), 7.08 (m, 2H,
Ph), 6.97 (m, 1H, Ph), 1.78-1.95 (m, 12H, PCH2CH3), 1.67 (s, 15H,
C5Me5), 0.96-1.06 (m, 18H, PCH2CH3). 31P{1H} NMR (C6D6): δ 23.8.
IR (Nujol mull, KBr): 2120 (s, νC≡C) cm-1. Anal. Calcd for C30H50-
SP2Ru: C, 59.47; H, 8.32; S, 5.29. Found: C, 58.64; H, 8.59; S, 5.05.
Synthesis of CpRu(PPh3)(C≡CPh)(µ-S)ZrCp2 (4a). To a solution
of Cp2ZrCl2 (65.4 mg, 0.22 mmol) in 20 mL of THF was added 0.29
mL of a 1.57 M hexane solution of n-BuLi (0.44 mmol) at -78 °C.
The solution turned yellow, to which 1a (0.18 g, 0.22 mmol) in THF
(20 mL) was immediately added at -78 °C. After warming the reaction
mixture to room temperature, the solution was stirred for 1 day. The
solvent was removed in vacuo, and the resulting solid was treated with
toluene (20 mL). An insoluble material was removed by centrifugation,
and the supernatant was evaporated to dryness. The residue was
recrystallized from THF/hexane (5 mL, 15 mL) to give 4a as red crystals
Synthesis of CpRu(PPh3)2(SC≡CPh) (1a). Addition of LiSCtCPh
(0.28 mmol) in THF (10 mL) to CpRu(PPh3)2Cl (0.20 g, 0.28 mmol)
in THF (30 mL) gave a dark red solution. The mixture was stirred
overnight at room temperature, and the solvent was removed in vacuo.
The residue was treated with toluene (50 mL) and centrifuged to remove
LiCl. The toluene solution was evaporated to dryness. The resulting
solid was dissolved in THF (5 mL) and layered with hexane (15 mL).
By standing the solution at room temperature, 1a was obtained as dark-
red crystals in 67% yield. 1H NMR (C6D6): δ 4.46 (s, 5H, C5H5), 6.95-
1
(0.12 g, 70%). H NMR (C6D6): δ 7.91-7.94 (m, 6H, Ph), 7.71 (m,
2H, Ph), 7.34 (m, 2H, Ph), 6.97-7.05 (m, 10H, Ph), 5.71 (s, 5H, Zr-
(C5H5)), 5.23 (s, 5H, Zr(C5H5)), 4.67 (s, 5H, Ru(C5H5)). 13C NMR
(C6D6): δ 88.27 (d, 2J C-P ) 2.9 Hz, Ru(C5H5)), 107.80 (s, Zr(C5H5)),
109.71 (s, Zr(C5H5)), 115.79 (s, Ru-C≡Câ), 126.38 (s, Ph), 129.32
7.04 (m, 19H, Ph), 7.1 (m, 2H, Ph), 7.5 (m, 12H, Ph), 7.6 (m, 2H, Ph).
2
13C NMR (C6D6): δ 74.40 (s, S-C≡Câ), 85.85 (t, J
) 1.9 Hz,
C-P
(s, Ph), 129.87 (m, Ph), 131.87 (s, Ph), 135.67(m, Ph), 138.76(s, Ph),
C5H5), 102.99 (t, 3JC-P ) 3.9 Hz, S-CR≡C), 125.53 (s, Ph), 128.91 (m,
Ph), 129.78 (s, Ph), 132.39 (s, Ph), 132.85 (s, Ph), 132.93(s, Ph), 134.75-
(m, Ph), 139.61(m, Ph). 31P{1H} NMR (C6D6): δ 42.1. IR (Nujol mull/
KBr): 2110 (s, νC≡C) cm-1. UV-visible (λmax, nm (ꢀ, M-1cm-1),
THF): 346 (15600). Anal. Calcd for C49H40SP2Ru: C, 71.42; H, 4.89;
S, 3.89. Found: C, 69.70; H, 5.04; S, 3.97.
2
139.10 (s, Ph), 188.65 (d, J
) 19.6 Hz, Ru-CR≡C). IR (Nujol
C-P
mull, KBr): 1926 (s, νC≡C) cm-1. Anal. Calcd for C41H35SPRuZr‚
1/2THF: C, 63.04; H, 4.80; S, 3.91. Found: C, 62.60; H, 5.11; S,
3.75.
Synthesis of CpRu(PPh3)(C≡CPh)(µ-Se)ZrCp2 (4b). This com-
pound was synthesized starting from Cp2ZrCl2 (0.038 g, 0.13 mmol),
n-BuLi (1.54 M, 0.16 mL, 0.25 mmol), and 2a (0.11 g, 0.13 mmol),
according to the procedure described for the synthesis of 4a. Compound
Synthesis of CpRu(PPh3)2(SC≡CSiMe3) (1b). Reaction of CpRuCl-
(PPh3)2 (0.32 g, 0.44 mmol) and LiSCtCSiMe3 (0.44 mmol) in THF
(30 mL) followed by a workup similar to that described above yielded
1
4b was obtained as brown crystals (0.09 g) in 84% yield. H NMR
1
dark-red crystals of 1b (0.23 g, 64%). H NMR (C6D6): δ 7.5 (m,
(C6D6): δ 7.90-7.94 (m, 6H, Ph), 7.72 (m, 2H, Ph), 7.36 (m, 2H, Ph),
7.18 (m, 1H, Ph), 6.98-7.04 (m, 9H, Ph), 5.66 (s, 5H, Zr(C5H5)), 5.18
12H, Ph), 6.95-7.00 (m, 18H, Ph), 4.40 (s, 5H, C5H5), 0.44 (s, 9H,
SiMe3). 31P{1H} NMR (C6D6): δ 42.2. IR (Nujol mull, KBr): 2033
(s, νC≡C) cm-1. Anal. Calcd for C46H44SP2SiRu: C, 67.37; H, 5.41; S,
3.91. Found: C, 67.83; H, 5.32; S, 3.84.
(s, 5H, Zr(C5H5)), 4.66 (s, 5H, Ru(C5H5)). 13C NMR (C6D6): δ 87.88
2
(d, J
) 2.9 Hz, Ru(C5H5)), 107.26(s, Zr(C5H5)), 109.10 (s, Zr-
C-P
(C5H5)), 116.98 (s, Ru-C≡Câ), 126.14 (s, Ph), 129.34 (s, Ph), 129.84
(m, Ph), 131.78 (s, Ph), 135.77(m, Ph), 138.92(s, Ph), 139.26 (s, Ph),
193.68 (d, 2J C-P ) 20.1 Hz, Ru-CR≡C). 31P{1H} NMR (C6D6): δ 50.9
(s). 77Se NMR (C6D6): δ 522 (br). IR (Nujol mull, KBr): 1920 (s,
Synthesis of CpRu(PPh3)2(SC≡CtBu) (1c). Reaction of CpRuCl-
(PPh3)2 (0.25 g, 0.34 mmol) and LiSCtCtBu (0.34 mmol) in THF (40
mL), and the subsequent workup similar to that used for isolation of
1
1a and 1b, provided 1c as dark-red crystals (0.15 g, 56%). H NMR
ν
C≡C) cm-1. Anal. Calcd for C41H35SePRuZr: C, 59.33; H, 4.25.
(C6D6): δ 7.7 (m, 4H, Ph), 6.9 (m, 26H, Ph), 4.44 (s, 5H, C5H5), 1.48
(s, 9H, CMe3). 31P{1H} NMR (C6D6): δ 42.5. IR (Nujol mull, KBr):
2127 (s, νC≡C) cm-1. Anal. Calcd for C47H44SP2Ru: C, 70.21; H, 5.52;
S, 3.99. Found: C, 70.28; H, 4.84; S, 3.76.
Synthesis of CpRu(PPh3)2(SeC≡CPh) (2a). Addition of a THF (0.6
mL) solution of LiSeCtCPh (0.30 mmol) to CpRuCl(PPh3)2 (0.21 g,
0.29 mmol) in THF (40 mL) followed by a workup similar to that
described above yielded dark-red crystals of 2a (0.16 g, 64%). 1H NMR
(CDCl3): δ 7.4 (m, 2H, Ph), 7.13-7.25 (m, 33H, Ph), 4.27 (s, 5H,
Found: C, 59.91; H, 4.56.
Synthesis of CpRu(CO)(C≡CPh)(µ-S)ZrCp2 (5a). A THF (20
mL) solution of 4a (0.20 g, 0.26 mmol) was stirred overnight under 1
atm of CO at room temperature. The solvent was removed in vacuo to
leave an orange solid. Washing the solid with hexane (3 × 20 mL)
1
gave 0.12 g of 5a as an orange powder (83%). H NMR (C6D6): δ
7.53 (m, 2H, Ph), 7.24 (m, 2H, Ph), 7.11 (m, 1H, Ph), 5.82 (s, 5H,
Zr(C5H5)), 5.46 (s, 5H, Zr(C5H5)), 4.83 (s, 5H, Ru(C5H5)). IR (Nujol
mull, KBr): 1965 (s, νC≡O), 1926 (s, νC≡C) cm-1
.
Synthesis of CpRu(CO)(C≡CPh)(µ-Se)ZrCp2 (5b). A THF (15
mL) solution of 4b (0.11 g, 0.13 mmol) was treated under 1 atm of
CO, as described for the synthesis of 5a. The solution was concentrated
to 2 mL in vacuo, and slow addition of hexane resulted in the depositing
of 5b as reddish brown crystals (0.05 g, 63%). H NMR (C6D6): δ
7.53 (m, 2H, Ph), 7.20 (m, 2H, Ph), 7.13 (m, 1H, Ph), 5.76 (s, 5H,
(8) (a) Raap, R.; Micetich, R, G. Can. J. Chem. 1967, 46, 1057-1062.
(b) M, Schmidt.; V, Potschka. Naturwissenschaften 1963, 50, 302.
(9) (a) Reid, A, F.; Wailes, P, C. Aust. J. Chem. 1966, 19, 309-312. (b)
Bruce, M, I.; Windsor, N, J. Aust. J. Chem. 1977, 30, 1601-1604.
(c) Coto, A.; Tenorio, M. J.; Puerta, M. C.; Valerga, P. Organo-
metallics 1998, 17, 4392-4399.
1

7074 Inorganic Chemistry, Vol. 40, No. 27, 2001
Sunada et al.
Table 1. Crystal Data for CpRu(PPh3)2(SCtCPh) (1a), CpRu(PPh3)2(SCtCtBu) (1c), CpRu(PPh3)2(SeCtCPh) (2a),
CpRu(PPh3)2(SeCtCSiMe3) (2b), Cp*Ru(PEt3)2(SCtCPh) (3), CpRu(PPh3)(CtCPh)(µ-S)ZrCp2 (4a), CpRu(PPh3)(CtCPh)(µ-Se)ZrCp2 (4b),
and CpRu(CO)(CtCPh)(µ-Se)ZrCp2 (5b)
1a
1c
2a
2b
3
4a
4b
5b
formula
mol wt
C49H40P2SRu C47H44P2SRu C52H40P2SeRu C46H44SiP2- C30H50P2SRu C41H35PSZr- C41H35PSe-
C24H20OSe-
ZrRu
895.67
SeRu
RuC4H8O
831.14
ZrRuC4H8O
902.06
823.93
803.94
906.87
866.92
605.80
(g mol-1
)
cryst syst
space group P21/n
(No. 14)
cryst color
cryst size
monoclinic
triclinic
P-1
(No. 2)
dark red
monoclinic
P21/n
(No. 14)
dark red
monoclinic
P21/n
(No. 14)
dark red
monoclinic
P21/n
(No. 14)
orange
triclinic
P-1
(No. 2)
red
triclinic
P-1
(No. 2)
brown
monoclinic
P21/n
(No. 14)
dark red
reddish brown
0.20 × 0.4
× 0.10
0.50 × 0.50
0.03 × 0.02
0.20 × 0.40
0.70 × 0.55 0.35 × 0.20
0.40 × 0.10
0.50 × 0.10
× 0.10
× 0.01
× 0.50
× 0.30
15.959(5)
15.207(5)
17.67(1)
× 0.15
11.3623(3)
14.1584(2)
18.4452(3)
111.9925(6)
95.9407(8)
92.0565(9)
2951.38(9)
4
× 0.05
× 0.01
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
14.4564(7)
18.6851(3)
18.1251(2)
99.030(5)
105.5330(4)
100.284(2)
3959.8(2)
4
10.2855(8)
13.976(2)
14.583(2)
16.007(4)
15.255(3)
18.023(4)
8.1073(6)
13.635(1)
18.153(1)
112.416(3)
97.3595(8)
91.569(9)
1837.7(2)
2
8.198(3)
13.851(5)
18.253(7)
16.400(5)
8.240(3)
16.908(4)
108.290(2)
108.62(2)
105.94(4)
97.215(7)
113.93(2)
1906.8(3)
2
4170(1)
4
4123(2)
4
1894(1)
2
2088(1)
4
Fcalc
1.382
1.400
1.444
1.396
1.363
1.545
1.581
1.894
(g cm-3
)
µ (Mo KR)
5.64
5.83
13.61
14.01
7.28
8.30
17.11
29.77
(cm-1
)
abs range
2θmax
(deg)
0.74-1.00
55
0.66-1.02
55
0.86-1.00
50
0.86-1.00
50
0.83-1.00
55
0.68-1.01
55
0.50-1.01
55
0.91-1.00
50
no. of meas
rflns
23579
8332
478
12987
8724
460
7940
4069
490
7856
5625
460
19867
5835
307
11922
5169
420
11004
3065
413
3824
2422
253
no. of obs
dataa
no. param
residuals
Rb
0.047
0.062
3.30
0.062
0.062
1.28
0.040
0.041
1.33
0.029
0.037
1.68
0.029
0.042
2.37
0.056
0.076
2.08
2
0.044
0.052
1.58
0.040
0.041
1.64
Rwc
GOFd
a Observation criterion I > 3σ(I). b R ) ∑|Fo| - |Fc|/∑ |Fo|. c Rw ) [{∑w (|Fo| - |Fc|)2}/∑wFo ]1/2
.
d GOF ) [{∑w(|Fo| - |Fc|)2}/(No - Np)]1/2
,
where No and Np denote the number of data and parameters.
Zr(C5H5)), 5.55 (s, 5H, Zr(C5H5)), 4.82 (s, 5H, Ru(C5H5)). 77Se NMR
(C6D6): δ 411(br). IR (Nujol mull, KBr): 1970 (s, νC≡O), 1925 (s,
at 0.5 ° increments of ω, to assess the crystal quality, and preliminary
unit cell parameters were calculated. The intensity images were
measured at 0.5 ° intervals of ω for a duration of 35 s for 1a, 152 s for
1c, 35 s for 3, 100 s for 4a, and 35 s for 4b. The frame data were
integrated using a d*TREK program package, and the data sets were
corrected for absorption using a REQAB program.
ν
C≡C) cm-1. Anal. Calcd for C18H20OSeRuZr: C, 48.38; H, 3.38.
Found: C, 48.72; H, 3.33.
Synthesis of CpRu(CNtBu)(C≡CPh)(µ-Se)ZrCp2 (6). To a THF
t
(5 mL) solution of 4b (0.063 g, 0.076 mmol) was added BuNC (8.5
µL, 0.076 mmol). After stirring the reaction mixture overnight at room
All calculations were performed with a TEXSAN program package.
All structures were solved by direct methods, and then, the structures
were refined by full-matrix least squares. Anisotropic refinement was
applied to all non-hydrogen atoms, and all the hydrogen atoms were
put at calculated positions. In the case of 4a and 4b, crystal solvents
(THF) were defined as constrained groups. Additional information is
available as Supporting Information.
temperature, the solution was concentrated to 2 mL. Addition of hexane
1
led to the formation of 6 as reddish brown crystals (0.03 g, 62%). H
NMR (C6D6): δ 7.73 (m, 2H, Ph), 7.28 (m, 2H, Ph), 7.14 (m, 1H, Ph),
5.83 (s, 5H, Zr(C5H5)), 5.67 (s, 5H, Zr(C5H5)), 4.95 (s, 5H, Ru(C5H5)),
0.97 (s, 9H, CMe3). IR (Nujol mull, KBr): 2120 (s, νC≡N), 1910 (s,
ν
C≡C) cm-1. Anal. Calcd for C28H29NSeRuZr: C, 51.67; H, 4.49; N,
2.15. Found: C, 51.01; H, 4.33; N, 1.86.
Results and Discussion
X-ray Crystal Structure Determination. Crystallographic data are
summarized in Table 1. Crystals of 2a, 2b, and 5b suitable for X-ray
analysis were mounted in glass capillaries and sealed under argon.
Diffraction data were collected at room temperature on a Rigaku
AFC7R diffractometer, employing graphite-monochromated Mo KR
radiation (λ ) 0.710 690 Å) and the ω - 2θ scan technique. Refined
cell dimensions and their standard deviations were obtained by least-
squares refinements of 25 randomly selected centered reflections. Three
standard reflections, monitored periodically for crystal decomposition
or movement, did not show intensity decay over the course of the data
collections. The raw intensities were corrected for Lorentz and
polarization effects. Empirical absorption corrections based on ψ scans
were successfully applied.
Synthesis of Ruthenium(II) Alkynethiolato and Alkyne-
selenolato Complexes. The alkynechalcogenolato complexes,
CpRu(PPh3)2(ECtCR) (E ) S, R ) Ph (1a), SiMe3 (1b), Bu
t
(1c); E ) Se, R ) Ph (2a), SiMe3 (2b)) and Cp*Ru(PEt3)2-
(SCtCPh) (3), were prepared by the reactions of CpRuCl-
(PPh3)2 and Cp*RuCl(PEt3)2 with 1 equiv of the corresponding
lithium alkynechalcogenolates, respectively, Scheme 1. After
standard workup, these complexes were isolated in 56-68%
yields as dark-red crystals for 1a, b, c, and 2a, b, and as orange
crystals for 3. These alkynechalcogenolato complexes were
characterized by elemental analysis, IR, and H, 31P{1H}, and
1
Crystals of 1a, 1c, 3, 4a, and 4b were mounted on top of quartz
fibers using perfluoro(polyoxypropylene ethyl ether) and were set on
a Rigaku AFC7 equipped with a MSC/ADSC Quantum1 CCD detector.
The measurements were made using Mo KR radiation at -80 °C under
a cold nitrogen stream. Four preliminary data frames were measured
77Se NMR spectra.
The presence of S- or Se-coordinated alkynechalcogenolato
ligands in 1-3 was indicated by strong IR bands in the 2037-
2127 cm-1 region assignable to the CtC stretching vibrational

Ruthenium Half-Sandwich Complexes
Inorganic Chemistry, Vol. 40, No. 27, 2001 7075
Scheme 1
Figure 1. Structure of CpRu(PPh3)2(SCtCPh) (1a) showing 50%
probablity ellipsoids.
Table 2. Comparison of the CtC Stretching Bands
CtC stretching band
complex
(cm-1
)
CpRu(PPh3)2(SCtCPh) (1a)
2110
2033
2127
2110
2037
2120
1926
1920
1926
1925
1910
CpRu(PPh3)2(SCtCSiMe3) (1b)
CpRu(PPh3)2(SCtCtBu) (1c)
CpRu(PPh3)2(SeCtCPh) (2a)
CpRu(PPh3)2(SeCtCSiMe3) (2b)
Cp*Ru(PEt3)2(SCtCPh) (3)
CpRu(PPh3)(CtCPh)(µ-S)ZrCp2 (4a)
CpRu(PPh3)(CtCPh)(µ-Se)ZrCp2 (4b)
CpRu(CO)(CtCPh)(µ-S)ZrCp2 (5a)
CpRu(CO)(CtCPh)(µ-Se)ZrCp2 (5b)
CpRu(CNtBu)(CtCPh)(µ-Se)ZrCp2 (6)
Figure 2. Structure of Cp*Ru(PEt3)2(SCtCPh) (3) showing 50%
probablity ellipsoids.
Table 3. Selected Bond Distances (Å) and Angles (deg) for
CpRu(PPh3)2(SCtCPh) (1a), CpRu(PPh3)2(SCtCtBu) (1c),
CpRu(PPh3)2(SeCtCPh) (2a), CpRu(PPh3)2(SeCtCSiMe3) (2b),
and Cp*Ru(PEt3)2(SCtCPh) (3)
mode. The νC≡C values of the coordinated alkynechalcogenolates
vary notably depending on the R substituents; interestingly,
choice of the chalcogen atom does not affect νC≡C very much,
as shown in Table 2. Among the three substituents, trimethysilyl
1a
1c
2a
2b
3
Ru-E
Ru-P1
Ru-P2
E-C1
2.4216(7) 2.4207(9) 2.5469(8) 2.5390(5) 2.4206(5)
2.3174(7) 2.3298(9) 2.317(2) 2.329(1) 2.3101(5)
2.3440(8) 2.317(1) 2.326(2) 2.3284(9) 2.3242(6)
1.668(3) 1.664(4) 1.828(7) 1.833(4) 1.676(2)
1
gives the lowest νC≡C value. The H NMR data for 1-3 are
C1-C2 (CtC) 1.207(5) 1.211(6) 1.196(9) 1.213(5) 1.214(3)
consistent with their formulations, and each of the 31P{1H} NMR
spectra exhibit a single resonance. In the 13C NMR spectra of
1a, the alkynyl R carbon resonance appears at 74.40 ppm with
a coupling with the 31P nuclei. In addition, the alkyneselenolato
complexes of 2a and 2b were characterized by the triplet signals
of 77Se NMR at -364 ppm (2JSe-P ) 21.0 Hz) and -362 ppm
(2JSe-P ) 20.7 Hz), respectively. These alkynethiolato and
alkyneselenolato complexes are air- and moisture-sensitive, but
are thermally robust. They show no sign of decomposition in
boiling THF and toluene for 4 days under argon.
Ru-E-C1
E-Ru-P1
E-Ru-P2
P1-Ru-P2
E-C1-C2
109.5(1) 112.9(1) 102.2(2) 105.7(1) 105.21(8)
89.49(2) 84.81(3) 93.28(4) 91.30(2) 89.83(2)
90.15(3) 90.58(3) 89.70(5) 91.74(2) 90.12(2)
103.17(3) 103.37(3) 102.31(6) 102.04(3) 91.32(2)
175.5(3) 173.3(4) 178.3(7) 176.6(4) 178.1(2)
P1-Ru-E-C1 165.7(1) 165.3(2) 156.7(2) 91.9(1)
P2-Ru-E-C2 91.1(1) 91.4(2) 101.0(2) 166.0(1) 58.33(9)
149.64(9)
are 0.117-0.126 Å longer than the Ru-S bonds of 1a and 1c,
which may reflect the increase in ionic radius from sulfur to
selenium.13 For 1a, 1c, 2a, and 2b, the alkyne groups bend up
toward Cp, thus orienting away from the phosphine ligands in
order to avoid steric congestion. On the other hand, the alkyne
group of 3 lies between the PEt3 and Cp* ligands, because the
bulkiness of Cp* comes into play. The Ru-E-C1 angles fall
in the normal range found in thiolato and selenolato com-
plexes.10-12,13b The Ru-S-C1 angles of 1a and 1c are larger
by 4-10° when compared with the Ru-Se-C1 angles of 2a
and 2b, the trend of which is normal for chalcogenolato
complexes.1,14 The CtC distances of 1a, 1c, 2a, 2b, and 3 are
essentially the same irrespective of substituents, and they are
Crystals of 1a, 1c, 2a, 2b, and 3 were subject to X-ray
crystallographic analysis. Because their molecular structures are
very much alike, only the ORTEP views of 1a and 3 are
presented in Figures 1 and 2, respectively. Selected bond
distances and angles of 1a, 1c, 2a, 2b, and 3 are summarized
in Table 3. These complexes assume a common three-legged
piano stool geometry with one chalcogen and two phosphorus
atoms, and alkynethiolato and alkyneselenolato ligands coor-
dinate at Ru from the S(Se) sites regardless of the substituents.
The Ru-S bond lengths of 2.4206(5)-2.4216(7) Å for 1a,
1c, and 3 are slightly shorter than those of the known Ru(II)
thiolato complexes, e.g., Ru(SC6H3Me2-2,6)2(CNtBu)4 (av. 2.463
Å),10 Ru(SPh)2(dmpe)2 (2.469 Å),11 and Ru(SC6H4Me-4)2(CO)2-
(PPh3)2 (2.460 Å).12 The Ru-Se bond distances of 2a and 2b
(11) Field, L. D.; Hambley, T. W.; Yau, B. C. K. Inorg. Chem. 1994, 33,
2009-2017.
(12) Jessop, P. G.; Retting, S. J.; Lee, C. L.; James, B. R. Inorg. Chem.
1991, 30, 4617-4627.
(13) (a) Shannon, R. D. Acta Crystallogr. 1976, A32, 751-767. (b) Millar,
M. M.; O’Sullivan, T.; de Vries, N.; Koch, S. A. J. Am. Chem. Soc.
1985, 107, 3714-3715.
(10) Mashima, K.; Kaneyoshi, H.; Kaneko, S.; Mikami, A.; Tani, K.;
Nakamura, A. Organometallics 1997, 16, 1016-1025.

7076 Inorganic Chemistry, Vol. 40, No. 27, 2001
Sunada et al.
Scheme 2
Figure 3. Structure of CpRu(PPh3)(CtCPh)(µ-S)ZrCp2 (4a) showing
50% probablity ellipsoids.
comparable to those of organic alkynes.15 The S-C1-C2 and
Se-C1-C2 spines are nearly linear. The S-C and Se-C
distances are similar to those of Cp2Ti(SCtCPh)2 (av. 1.686
Å) and (C5H4Me)2Ti(SeCtCPh)2 (av. 1.848 Å),1 and fall in
the normal range of S(Se)-C single bond lengths. These
geometric parameters clearly show that the alkynethiolates
and alkyneselenolates coordinate at Ru as ordinal thiolate
ligands,1,2,7b,16 and that there is no contribution of the thioketenyl
and selenoketenyl resonance forms in their structures as was
proposed for CpRu(PMe3)2(η1-C(Ph)dCdS).7
Table 4. Selected Bond Distances (Å) and Angles (deg) for
CpRu(PPh3)(CtCPh)(µ-S)ZrCp2 (4a),
CpRu(PPh3)(CtCPh)(µ-Se)ZrCp2 (4b), and
CpRu(CO)(CtCPh)(µ-Se)ZrCp2 (5b)
4a
4b
5b
Ru-Zr
3.161(1)
2.414(2)
2.444(3)
2.285(2)
1.976(8)
2.418(7)
2.550(7)
1.22(1)
3.219(2)
2.527(2)
2.598(2)
2.282(4)
1.99(1)
2.43(1)
2.53(1)
1.20(2)
3.1420(9)
2.494(1)
2.588(1)
Ru-E
Zr-E
Ru-P
Ru-C1
1.959(7)
2.424(7)
2.529(8)
1.22(1)
Zr-C1
Reactions of Ruthenium(II) Alkynechalcogenolato Com-
plexes with Zirconocene(II). It is known that treatment of 2
equiv of n-BuLi with Cp2ZrCl2 at low temperature produces a
highly reactive zirconocene(II) complex via formation of Cp2-
Zr(n-Bu)2 and then Cp2Zr(η2-CH2dCHCH2CH3).17 We exam-
ined the reaction of CpRu(PPh3)2(SCtCPh) (1a) with Cp2Zr,
which was generated in situ at -78 °C in THF. The consequence
was isolation of a hetero-bimetallic complex, CpRu(PPh3)-
(CtCPh)(µ-S)ZrCp2 (4a), as red crystals in 70% yield (Scheme
2). During this reaction, one phosphine molecule was liberated
from 1a, and C-S bond cleavage of the alknyethiolato ligand
took place, presumably via oxidation of the zirconium atom from
II to IV. Thus generated are alkynyl and sulfide moieties
bridging the ruthenium and zirconium atoms. A similar C-S
bond cleavage was reported to occur in the reaction of
RCtCSC2H5 (R ) CH3, Ph) with Fe2(CO)9, generating Fe2-
(CO)6(µ-SC2H5)(µ-CtCR).18 The reaction of CpRu(PPh3)2-
(SeCtCPh) (2a) with Cp2Zr gave rise to an analogous alkynyl-
selenido complex CpRu(PPh3)(CtCPh)(µ-Se)ZrCp2 (4b) as
brown crystals in 84% yield. Complexes 4a and 4b are air- and
moisture-sensitive, but are thermally stable. No decomposition
occurred in C6D6 at 80 °C for 1 day in the absence of air, as
Zr-C2
C1-C2 (CtC)
Ru-C24
CtO
1.84(1)
1.128(9)
76.35(3)
91.0(3)
103.3(2)
88.8(2)
117.1(2)
28.4(2)
170.9(7)
154.9(8)
177.8(9)
Ru-E-Zr
Ru-C1-Zr
E-Ru-C1
E-Zr-C1
E-Zr-C2
C1-Zr-C2
Ru-C1-C2
C1-C2-C3
Ru-CtO
81.18(7)
91.4(2)
89.5(2)
85.0(2)
112.0(2)
28.4(3)
77.82(6)
92.8(4)
97.7(3)
85.6(3)
112.4(4)
27.8(5)
173(1)
173.0(6)
159.7(8)
159(2)
2. Interactions between CtC π-electrons and a metal center
are thus suggested.19,20 The 13C NMR spectrum of 4a shows
2
the alkynyl carbon signals at 188.65 ppm (CR, JC-P ) 19.6
Hz) and 115.79 ppm (Câ), which are substantially shifted
downfield compared with those of 1a, and the alkynyl carbon
signals of the Se-congener (4b) appear in a similar region. The
situation is similar to the downfield shifts of the 13C NMR
signals of {(η5-C5MeH4)Zr(µ-CtCPh)}2 (228.9 ppm, CR; 154.7
ppm, Câ)19 and Cp2Zr(µ-CtCSiMe3)Ni(PPh3)(µ-CtCSiMe3)
(233.9 ppm, CR; 112.1 ppm, Câ),21a relative to those of (η5-C5-
MeH4)2Zr(CtCPh)2 (142.8 ppm, CR; 122.1 ppm, Câ) and NiCl-
(CtCSiEt3)(PMe3)2 (121.73 and 121.15 ppm, CRand Câ).21b
The molecular structures of 4a and 4b were established by
X-ray analysis. The crystals of 4a and 4b are isomorphic, and
their molecular structures are also very similar. Figure 3 shows
the ORTEP view of 4a, and the selected bond distances and
angles of 4a and 4b are listed in Table 4. The two metal centers
are linked by µ-chalcogenido and µ-σ, π-alkynyl moieties. The
alkynyl bridge is unsymmetric in that the terminal carbon of
alkynyl is σ-bonded to ruthenium, while zirconium interacts with
1
1
monitored by the H NMR spectra. In each of the H NMR
spectra, three Cp signals of equal intensity were observed along
with the phenyl proton signals, and thereby, the two Cp rings
at Zr are not chemically equivalent. The 77Se NMR spectrum
of 4b consists of a somewhat broad peak at δ 522 and exhibits
a substantial low-field shift relative to those of the alkynese-
lenolato complexes, 2a and 2b. The IR spectra of 4a and 4b
are featured by the CtC stretching bands appearing at 1926
and 1920 cm-1, which are significantly shifted to lower
frequencies compared to those of 1a and 2a, as shown in Table
(14) Howard, W. A.; Trnka, T. M.; Parkin, G. Inorg. Chem. 1995, 34,
5900-5909.
(19) Erker, G.; Fro¨mberg, W.; Benn, R.; Mynott, R.; Angermund, K.;
Kru¨ger, C. Organometallics 1989, 8, 911-920.
(15) March, J. W. AdVanced Organic Chemistry; Wiley: New York, 1985.
(16) Beswick, M. A.; Raithby, P. R.; Steiner, A.; Vallat, J. C.; Verhorevoort,
K. L.; Wright, D. S. J. Chem. Soc., Dalton Trans. 1996, 2183-2184.
(17) Negishi, E.; Holmes, S. J.; Tour, J. M.; Miller, J. A.; Cederbaum, F.
E.; Swanson, D. R.; Takahashi, T. J. Am. Chem. Soc. 1989, 111, 3336-
3346.
(20) Akita, M.; Terada, M.; Oyama, S.; Moro-oka, Y. Organometallics
1990, 9, 816-825.
(21) (a) Rosenthal, U.; Pulst, S.; Arndt, P.; Ohff, A.; Tillack, A.; Baumann,
W.; Kempe, R.; Burlakov, V. V. Organometallics 1995, 14, 2961-
2968. (b) Klein, H.-F.; Zwiener, M.; Petermann, A.; Jung, T.; Cordier,
G.; Hammerschmitt, B.; Florke, U.; Haupt, H.-J.; Dartiguenave, Y.
Chem. Ber. 1994, 127, 1569-1578.
(18) Rosenberger, C.; Steunou, N.; Jeannin, S.; Jeannin, Y. J. Organomet.
Chem. 1995, 494, 17-35.

Ruthenium Half-Sandwich Complexes
Inorganic Chemistry, Vol. 40, No. 27, 2001 7077
both alkynyl carbons in a side-on fashion. The Ru-C1 distances
are comparable to those found in known Ru(II) alkynyl com-
plexes, e.g., CpRu(CtCPh)(dppe) (2.009(3) Å)22 and [Cp*Ru-
(CtCTol)(µ-SiPr)]2 (2.04(3), 2.00(2) Å).23 The Zr-C2 distances
are considerably longer than the Zr-C1 distances, and the
phenyl group is bent away from the zirconium side by ca. 20°.
The Ru-C1-C2 bonds are approximately linear. These geo-
metric features are often observed for dinuclear complexes with
unsymmetrically bridged µ-σ, π-alkynyl ligands.20,21a,24 Bending
of the phenyl group, along with the aforementioned significant
shift of νC≡C values to lower frequencies, indicate Zr-alkyne
π-interactions. On the other hand, elongation of the CtC bonds
is not discernible in the X-ray data, and the Zr-C2 distances
are very long. Thus Zr-alkyne back-bonding, if any, must be
weak. This view is consistent with our assignment of the Zr-
(IV) oxidation state, as described later, for a d0 metal center
does not back-donate electrons to a π* orbital(s) of alkyne.
The phenyl ring is oriented perpendicular to the RuZrC1C2
plane, as is incarnated by the dihedral angle of 87.5 ° for 4a
and 88.4 ° for 4b. The RuZrEC1 quadrilateral is puckered by
25.7 ° for 4a and 25.5 ° for 4b, and the Ru-E-Zr angles are
acute. The Zr-Ru distances of 3.161(1) and 3.219(2) Å are
too long to invoke metal-metal bonding.25 The Ru atom is
surrounded by one Cp-, one µ-E-, and one σ-bonded alkynyl-,
while the Zr atom is surrounded by two Cp- ligands, one µ-E-,
and one neutral CtC. From the ligand arrangements in 4a and
4b, one may be tempted to consider the formal oxidation states
of the metal centers to be Ru(III) and Zr(III). However, the
metal-metal separation is large and yet the complexes are
diamagnetic, according to the NMR spectra. The related
Zr(III)/Zr(III)19,26 and Zr(III)/Ni(I)21a dinuclear complexes were
reported to be diamagnetic, while metal-metal distances are
long. It was suggested that magnetic coupling via the alkynyl
bridging group was responsible for the diamagnetism. We
alternatively suggest a zwitterionic form for 4a and 4b with
Zr(IV)+ and Ru(II)- centers. In fact, the metal-ligand bond
distances fit this interpretation.
Scheme 3
Scheme 4
A mechanism for the formation of 4a and 4b is proposed in
Scheme 3. The first step is interaction of the zirconocene(II)
center with the alkyne carbons and/or the chalcogen atom of
alkynechalcogenolate. This assumption is not labored consider-
ing the coordinative unsaturation of zirconocene(II). In close
proximity to Zr(II), oxidative addition of the C-S(Se) bonds
of alkynechalcogenolates would be promoted to produce a
chalcogen-bridged Zr/Ru dinuclear complex (A). Then, the
alkynyl ligand moves from zirconium to ruthenium, resulting
in the formation of 4a and 4b.
(22) Bruce, M. I.; Humphrey, H. G.; Snow, M. R.; Tiekink, E. R. T. J.
Organomet. Chem. 1986, 314, 213-225.
(23) Matsuzaka, H.; Hirayama, Y.; Nishio, M.; Mizobe, Y.; Hidai, M.
Organometallics 1993, 12, 36-46.
(24) (a) Ciriano, M.; Howard, J. A. K.; Spencer, J. L.; Stone, G. A.;
Wadepohl, H. J. Chem. Soc., Dalton Trans. 1979, 1749-1756. (b)
Fornie´s, J.; Lalinde, E.; Mart´ınez, F.; Moreno, M. T.; Welch, A. J. J.
Organomet. Chem. 1993, 455, 271-281. (c) Janssen, M. D.; Ko¨hler,
K.; Herres, M.; Dedieu, A.; Smeets, W. J. J.; Spek, A. L.; Grove, D.
M.; Lang, H.; van Koten, G. J. Am. Chem. Soc. 1996, 118, 4817-
4829. (d) Back, S.; Rheinwald, G.; Lang, H. J. Organomet. Chem.
2000, 601, 93-99.
Reactions of the Heterobimetallic Complexes 4a and 4b
with CO and BuNC. Reactivity of CpRu(PPh3)(CtCPh)-
t
(µ-E)ZrCp2 (E ) S (4a), Se (4b)) was investigated by NMR
tube experiments. By monitoring the 1H NMR spectra in C6D6,
we found that these heterobimetallic complexes reacted cleanly
with CO and tBuNC, liberating the phosphine ligand at Ru. On
the other hand, 4a and 4b were inert toward 1 atm H2 and CO2
and did not react with PhNCO or PhCtCH either. On a
preparative scale, 4a and 4b were treated in THF with 1 atm
CO at room temperature, and we isolated the carbonyl com-
plexes, CpRu(CO)(CtCPh)(µ-E)ZrCp2 (E ) S (5a), Se (5b)),
as an orange powder in 83% yield and as reddish brown crystals
(25) (a) Casy, C. P.; Jordan, R. F.; Rheingold, A. L. J. Am. Chem. Soc.
1983, 105, 665-667. (b) Casy, C. P.; Jordan, R. F.; Rheingold, A. L.
Organometallics 1984, 3, 504-506. (c) Gade, L. H.; Schubart, M.;
Findeis, B.; Fabre, S.; Bezougli, I.; Lutz, M.; Scowen, I. J.; McPartlin,
M. Inorg. Chem. 1999, 38, 5282-5294. (d) Gade, L. H.; Friedrich,
S.; Tro¨sch, D. J. M.; Scowen, I. J.; McPartlin, M. Inorg. Chem. 1999,
38, 5295-5307.
(26) Lang, H.; Blau, S.; Nuber, B.; Zsolnai, L. Organometallics 1995, 14,
3216-3223.

7078 Inorganic Chemistry, Vol. 40, No. 27, 2001
Sunada et al.
in 63% yield, respectively. Analogously, addition of 1 equiv of
tert-butyl isocyanide to a THF solution of 4b led to the
formation of CpRu(CNtBu)(CtCPh)(µ-Se)ZrCp2 (6), which was
isolated as reddish brown crystals in 62% yield (Scheme 4).
The 1H NMR spectra of 5a, 5b, and 6 are consistent with their
1
formulation, and there appear three Cp H NMR signals, as in
the case of 4a and 4b. The strong IR bands at 1965 cm-1 for
5a and 1970 cm-1 for 5b can be assigned to the CO stretching
vibrations, and the tBuNC band of 6 appears at 2120 cm-1. The
77Se NMR signal of 5b is shifted upfield by 111 ppm compared
to that of 4b, while the CtC stretching bands in the IR spectra
of 5a, 5b, and 6 appear in the region similar to those of 4a and
4b. These spectroscopic data indicate that the dinuclear struc-
tures of 4a and 4b are retained when phosphine is replaced by
Figure 4. Structure of CpRu(CO)(CtCPh)(µ-Se)ZrCp2 (5b) showing
50% probablity ellipsoids.
angle of the ring and the RuZrC1C2 least-squares plane is 12.2°.
Thus, the phenyl ring is oriented in such a way that delocal-
ization of electrons may occur between the alkyne portion and
the ring. An interesting feature of the dinuclear structure of 5b
is that the ZrRuSe/ZrRuC1 dihedral angle is as small as 7.2°,
and therefore, the ZrRuSeC1 quadrilateral core is nearly planar,
which is in contrast to the puckered cores of 4a and 4b.
t
CO or BuNC at the Ru site.
The dinuclear structure of 5b was confirmed by an X-ray
crystallographic study, as shown in Figure 4. The selected bond
distances and angles are added to the third column of Table 4.
The Ru-Se bond length and Ru-Zr distance of 5b are
shortened by 0.077 and 0.033 Å compared with the correspond-
ing distances of 4b. The large Ru dπ-CO π* back-donation
may have strengthened the Ru-Se bond, which would in turn
shorten the Ru-Zr distance. Or, the shortening may be ascribed
to the steric factor in that CO is less sterically demanding than
PPh3. The Ru-CO bond is substantially shorter than the Ru-
CtCPh bond, showing that back-donation occurs much more
effectively to CO than to the alkynide ligand.27 The dihedral
Supporting Information Available: Eight X-ray crystallographic
files in CIF format. This material is available free of charge via the
Internet at http//pubs.acs.org.
IC010826H
(27) Kostic, N. M.; Fenske, R. F. Organometallics 1982, 1, 974-982.