Half-sandwich ruthenium phosphine complexes with sulfur-donor ligands. X-ray crystal structures of [Cp*RuH(SH)(PEt3)2][BPh4] and [Cp*Ru(S2COiPr)(PEt3)]

Article abstract of DOI:10.1021/om980340h

The complexes [CpRuCl(PEt₃)₂ (1) and [CpRuCl(PMeⁱPr₂)(PPh₃)] (2) react with H₂S in EtOH in the presence of NaBPh₄ furnishing the green persulfide derivatives [{CpRu(L)}₂

Full text of DOI:10.1021/om980340h

4392
Organometallics 1998, 17, 4392-4399
Ha lf-Sa n d w ich Ru th en iu m P h osp h in e Com p lexes w ith
Su lfu r -Don or Liga n d s. X-r a y Cr ysta l Str u ctu r es of
[Cp *Ru H(SH)(P Et3)2][BP h 4] a n d [Cp *Ru (S2COiP r )(P Et3)]
Alberto Coto, Manuel J ime´nez Tenorio, M. Carmen Puerta,* and Pedro Valerga
Departamento de Ciencia de Materiales e Ingenier´ıa Metalu´rgica y Quı´mica Inorga´nica,
Facultad de Ciencias, Universidad de Ca´diz, Apartado 40, 11510 Puerto Real, Ca´diz, Spain
Received May 4, 1998
The complexes [CpRuCl(PEt3)2] (1) and [CpRuCl(PMeiPr2)(PPh3)] (2) react with H2S in
EtOH in the presence of NaBPh4 furnishing the green persulfide derivatives [{CpRu(L)}2-
(µ-S2)][BPh4]2 (L ) (PEt3)2, (PMeiPr2)(PPh3)), which were also obtained by reaction of 1 or 2
with elemental sulfur and NaBPh4 in MeOH. At variance with this, the reaction of [Cp*RuCl-
(PEt3)2] (3) with H2S in EtOH afforded the RuIV hydrido-metallothiol [Cp*RuH(SH)(PEt3)2]-
[BPh4], which has been structurally characterized, derived from the oxidative addition of
SH2 to the electron-rich RuII moiety {[Cp*Ru(PEt3)2]+}. This compound is oxidized to yield
the persulfide complex [{Cp*Ru(PEt3)2}2(µ-S2)][BPh4]2, which was also obtained by reaction
of 3 with elemental sulfur. The reaction of 1, 2, and 3 with 2-mercapto-pyridine (HSPy) in
EtOH yielded cationic complexes in which HSPy is tautomerized to its 1H-pyridine-thione
form as inferred from spectral data. Compound 1 reacts with potassium alkyl-xanthates
KS2COR (R ) Me, Et, iPr) yielding compounds of the type [CpRu(η1-S2COR)(PEt3)2], whereas
the reaction of 2 and 3 led respectively to the complexes [CpRu(η2-S2COR)(PMeiPr2)] and
[Cp*Ru(η2-S2COR)(PEt3)], which contain one bidentate xanthate and one phosphine. The
X-ray crystal structure of [Cp*Ru(S2COiPr)(PEt3)] was determined. In analogous fashion,
the reaction of 1 with sodium diethyldithiocarbamate yielded [CpRu(η1-S2CNEt2)(PEt3)2],
whereas 2 and 3 afforded the corresponding derivatives [CpRu(η2-S2CNEt2)(PMeiPr2)] and
[Cp*Ru(η2-S2CNEt2)(PEt3)].
In tr od u ction
complexes containing coordinated H2S.4,10-13 Those
reported are in general rather unstable and very reac-
tive, and only in recent years have H2S complexes been
unequivocally characterized by X-ray crystallogra-
phy.12,13 The first structure was reported by Sellmann
and co-workers for the RuII complex [Ru(‘S4’)(PPh3)-
(SH2)]‚THF (‘S4’ ) 1,2-bis[(2-mercaptophenol)thio]-
ethane), the crystal stability resulting from intermo-
lecular H-bonding involving the THF solvate and strong
S-H‚‚‚S bridging.12 More recently, the crystal structure
of the adduct [RuCl2(P-N)(PTol3)(SH2)]‚0.5 THF‚0.41H2O
(P-N ) o-(diphenylphosphino)-N,N-dimethylaniline)
has been reported, this being the first example of a
structurally characterized transition metal-H2S com-
plex formed under ambient conditions.4,13 This sort of
complexes easily undergoes a variety of chemical trans-
formations which generally lead to oligomeric sulfur-
bridged species.10,12 At variance with this, oxidative
addition of H2S at a metal center to yield hydrido-
There has been increasing interest in the chemistry
of transition metal complexes with sulfur-containing
ligands1 because they provide model compounds for
biologically redox-active metalloproteins2 and other
systems involved in processes such as nitrogen fixation.3
If H2S is considered, the interest arises not only because
of its relevance to the biological sulfur cycle but also
for its implication in the formation of ores and in
hydrodesulfurization catalysis, as well as the potential
use of H2S as a source of H2 and organosulfur com-
pounds.4-9 However, there are very few examples of
(1) Blower, P. G.; Dilworth, J . R. Coord. Chem. Rev. 1987, 76, 121.
Sacconi, L.; Mani, F.; Bencini, A. In Comprehensive Coordination
Chemistry; Wilkinson, G., Gillard, R. D., McCleverty, J . A., Eds.;
Pergamon: Oxford, 1987; Vol. 5, Chapter 5.
(2) Power, P. P.; Shouer, S. C. Angew. Chem., Int. Ed. Engl. 1991,
30, 330.
(3) Leigh, G. J . Acc. Chem. Res. 1992, 25, 177. Shilov, A. E. New J .
Chem. 1992, 16, 213.
(4) J ames, B. R. Pure Appl. Chem. 1997, 69, 2213.
(5) J essop, P. G.; Lee, C.-L.; Rastar, G.; J ames, B. R.; Lock, C. J . L.;
Faggiani, R. Inorg. Chem. 1992, 31, 4601.
(6) Gates, B. C.; Katzer, J . R.; Schuit, G. C. Chemistry of Catalytic
Processes; McGraw-Hill: New York, 1979; Chapter 5. Angelici, R. J .
Acc. Chem. Res. 1988, 21, 387.
(11) Ku¨hn, C. G.; Taube, H. J . Am. Chem. Soc. 1976, 98, 689.
Herberhold, M.; Su¨ss, G. Angew. Chem., Int. Ed. Engl. 1976, 15, 366.
Ugo, R.; La Monica, G.; Cenini, S.; Segre, A.; Conti, F. J . Chem. Soc.
A 1971, 522.
(12) Sellmann, D.; Lechner, P.; Knoch, F.; Moll, M. Angew. Chem.,
Int. Ed. Engl. 1991, 30, 552. Sellmann, D.; Lechner, P.; Knoch, F.; Moll,
M. J . Am. Chem. Soc. 1992, 114, 922.
(7) Lee, C.-L.; Besenyei, G.; J ames, B. R.; Nelson, D. A.; Lilga, M.
A. J . Chem. Soc., Chem. Commun. 1985, 1175.
(8) (a) Mueting, A. M.; Boyle, P.; Pignolet, L. H. Inorg. Chem. 1984,
23, 44. (b) Bianchini, C.; Mealli, C.; Meli, A.; Sabat, M. Inorg. Chem.
1986, 25, 4617. (c) Carney, M. J .; Walsh, P. J .; Bergman, R. M. J . Am.
Chem. Soc. 1990, 112, 6426.
(9) Rabinovich, D.; Parkin, G. J . Am. Chem. Soc. 1991, 113, 5904.
(10) Amarasekara, J .; Rauchfuss, T. B. Inorg. Chem. 1989, 28, 3875.
(13) Mudalige, D. C.; Ma, E. s.; Rettig, S. J .; J ames, B. R.; Cullen,
W. R. Inorg. Chem. 1997, 36, 5426.
(14) Osakada, M.; Yamamoto, Y.; Yamamoto, A. Inorg. Chim. Acta
1984, 90, L5.
(15) J essop, P. G.; Rettig, S. J .; Lee, C.-L.; J ames, B. R. Inorg. Chem.
1991, 30, 4617.
S0276-7333(98)00340-9 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 09/03/1998

Half-Sandwich Ruthenium Phosphine Complexes
Organometallics, Vol. 17, No. 20, 1998 4393
presence of PEt3. IR spectra were recorded in Nujol mulls on
metallothiol species seems to be a more common reac-
tivity pattern.4,5,8,14,15 It has been observed in reactions
with hydrides and other electron-rich metal complexes,
although very often the hydrido-metallothiol reacts
further with H2S, yielding bis(mercapto) complexes.
Thus, the reactions of both [Ru(CO)2(PPh3)3] and [Ru-
(H)2(CO)2(PPh3)2] with H2S at room temperature af-
forded [RuH(SH)(CO)2(PPh3)2] and [Ru(SH)2(CO)2(PPh3)2]
sequentially.5 In analogous fashion, the reaction of
[Ru(H)2(dppm)2] (dppm ) 1,2-bis(diphenylphosphino)-
methane) with H2S yielded [RuH(SH)(dppm)2], which
converts to a mixture of cis- and trans-[Ru(SH)2(dppm)2]
upon heating or prolonged stirring under H2S,5 whereas
[RuH(SH)(PPh3)3] has been obtained starting from [Ru-
(H)2(PPh3)4] or [Ru(H)2(H2)(PPh3)3] and H2S.14 Ama-
rasekara and Rauchfuss have suggested the possibility
of an equilibrium between the unstable H2S complex
[CpRu(SH2)(PPh3)2]+ and its hydrido-metallothiol tau-
tomer [CpRuH(SH)(PPh3)2]+, but no experimental evi-
dence supporting the existence of the RuIV hydrido-
metallothiol was found.10 Other RuII hydrido-metallothiol
derivatives have been prepared by metathetical ex-
change of NaSH with chloro-hydride complexes, i.e.,
coordinatively unsaturated [RuH(SH)(CO)(PiPr3)2].16
As a part of our studies on the chemistry of half-
sandwich ruthenium complexes with sulfur-containing
ligands, we have now considered their reactivity toward
H2S. No H2S adducts were isolated or detected, and
instead, binuclear persulfido complexes were obtained.
However, in the course of the reaction of H2S with the
electron-rich complex [Cp*RuCl(PEt3)2] the unprec-
edented RuIV hydrido-metallothiol [Cp*RuH(SH)(PEt3)2]-
[BPh4] was obtained, and its structure has been deter-
mined by X-ray crystallography. We have also prepared
and characterized a series of ruthenium derivatives with
sulfur-donor ligands such as 2-mercapto-pyridine, alkyl-
xanthates, and diethyldithiocarbamate, in an attempt
to establish the possible factors that control their
different ways of coordination. From this study, alkyl-
xanthates and diethylthiocarbamate might be used as
hemilabile ligands in organometallic complexes given
their capability for adopting an η1- or η2-coordination
mode depending upon the conditions.17
a
Perkin-Elmer FTIR Spectrum 1000 spectrophotometer.
UV-vis measurements were made using a Milton Roy Spec-
tronic 3000 diode array. NMR spectra were taken on Varian
Unity 400 MHz or Varian Gemini 200 MHz spectrometers.
Chemical shifts are given in ppm from SiMe4 (1H and 13C{1H})
or 85% H3PO4 (31P{1H}). Microanalyses were performed by
the Serveis Cient´ıfico-Te`cnics, Universitat de Barcelona.
CAUTION: H2S is extremely toxic, and all the preparations
involving its use should be carried out in a well-ventilated fume
hood!
[Cp Ru (P Et3)2Cl] (1) a n d [Cp Ru (P P h 3)(P iP r 2Me)Cl] (2).
To a slurry of [CpRuCl(PPh3)2] (1.97 g, ca. 2.7 mmol) in
toluene (15 mL) was added PEt3 (0.8 mL, ca. 5.4 mmol) or
PMeiPr2 (0.4 mL, ca. 2.7 mmol). The mixture was refluxed
for 3 h. Then, the solvent was removed in vacuo. The
resulting orange oil was dissolved in each case in the minimum
amount of petroleum ether and passed through a silica gel
chromatographic column in order to remove PPh3. This can
be done in the air. The column was eluted with petroleum-
Et2O (3:1 v/v). The fraction corresponding to the orange band
was collected. Removal of the solvent afforded an orange (1)
or yellow (2) microcrystalline material. Analytically pure
samples were obtained by recrystallization from petroleum-
Et2O. Yield: 75-80%. 1: Anal. Calcd for C17H35ClP2Ru: C,
46.6; H, 8.06. Found: C, 46.8; H, 8.02. NMR (C6D6) δ: (1H)
1.08 (m, PCH2CH3); 1.78 (dm, PCH2CH3); 4.39 (s, C5H5). 31P-
{1H}: 32.7 (s). 13C{1H}: 8.27 (s, P(CH2CH3)3); 21.2 (t, J (C,P)
) 12.4 Hz, P(CH2CH3)3); 76.9 (s, C5H5). 2: Anal. Calcd for
C30H37ClP2Ru: C, 60.4; H, 6.26. Found: C, 60.4; H, 6.29. NMR
(C6D6) δ: (1H) 0.64 (d, PCH3); 0.82, 1.00, 1.27 (m, P(CH-
(CH3)2)2); 1.93 (dm, P(CH(CH3)2)2); 4.33 (s, C5H5); 7.05, 7.82
(m, P(C6H5)3). 31P{1H}: 45.0 d, 39.5 d, J (P,P) ) 40.9 Hz. 13C-
{1H}: 3.6 (d, J (C,P) ) 20.5 Hz, P(CH3(CH(CH3)2)2)); 18.5, 18.7,
18.9, 19.7 (s, PCH3(CH(CH3)2)2); 32.5 (dd, J (C,P) ) 21.2 Hz,
P(CH3(CH(CH3)2)2)); 79.8 (s, C5H5); 129.1, 127.6 (s, P(C6H6)3),
134.9 (d, J (C,P) ) 10.3 Hz, P(C6H5)3).
[Cp *Ru (P Et3)2Cl] (3). To a suspension of [{Cp*RuCl2}2]
(0.85 g, 1.35 mmol) in THF (100 mL) were added PEt3 (0.8
mL, 5.4 mmol) and an excess of zinc dust. The mixture was
stirred for 45 min. The resulting suspension was allowed to
settle, and the liquor transferred to another flask. The solvent
was removed in vacuo, and the residue extracted with Et2O.
Filtration, concentration, and cooling to -20 °C afforded
orange crystals. Yield: 0.55 g, 80%. Anal. Calcd for C22H45
-
ClP2Ru: C, 52.5; H, 8.01. Found: C, 52.8; H, 7.96. NMR
(CDCl3) δ: (1H) 1.06 (m, PCH2CH3); 1.58 (t, J (H,P) ) 2 Hz,
C5(CH3)5); 1.82 (dm, PCH2CH3). 31P{1H}: 22.3 (s). 13C{1H}:
9.2 (s, P(CH2CH3)3); 10.8 (s, C5(CH3)5); 21.3 (t, J (C,P) ) 12.2
Hz, P(CH2CH3)3); 87.3 (t, J (C,P) ) 1 Hz, C5(CH3)5).
Exp er im en ta l Section
[{Cp R u (P E t3)2}2(µ-S2)][BP h 4]2 (4). Met h od A (fr om
H2S). To a suspension of 1 (0.13 g, 0.3 mmol) in EtOH (20
mL) was added an excess of NaBPh4 (ca. 0.3 g), and then H2S
was bubbled through the stirred mixture at room temperature
for 2-3 min. A green precipitate was formed, which was
filtered off, washed with EtOH and petroleum ether, and dried
in vacuo. It was recrystallized from CH2Cl2/EtOH.
Meth od B (fr om Elem en ta l Su lfu r ). A suspension of 1
(0.22 g, 0.5 mmol) in MeOH was treated with the stoichiomet-
ric amount of elemental sulfur (0.016 g, ca. 0.5 mmol) and an
excess of NaBPh4 (ca. 0.3 g), and the mixture stirred overnight.
A green, microcrystalline precipitate was obtained, which was
filtered off, washed with EtOH and petroleum ether, and dried.
This material was recrystallized as above.
All synthetic operations were performed under a dry dini-
trogen or argon atmosphere following conventional Schlenk
techniques. THF, Et2O, and petroleum ether (boiling point
range 40-60 °C) were distilled from the appropriate drying
agents. All solvents were deoxygenated immediately before
use. PEt3 was purchased from Aldrich, whereas PMeiPr2 was
obtained by reaction of PCliPr2 (Aldrich) with MeMgI in Et2O.
[CpRuCl(PEt3)2] and [CpRuCl(PMeiPr2)(PPh3)] were obtained
by thermal displacement of PPh3 from [CpRuCl(PPh3)2]18 by
the corresponding phosphine. [Cp*RuCl(PEt3)2] was prepared
by Zn reduction of the dimer [{Cp*RuCl2}2]19 in THF in the
(16) Buil, M. L.; Elipe, S.; Esteruelas, M. A.; On˜ate, E.; Peinado,
E.; Ru´ız, N. Organometallics 1997, 16, 5748.
(17) Baker, P. K.; Fraser, S. G.; Kendrick, D. A. J . Chem. Soc.,
Dalton Trans. 1991, 131. Baker, P. K.; Harman, M. E.; Highes, S.;
Hursthouse, M. B.; Malik, K. M. A. J . Organomet. Chem. 1995, 498,
257.
(18) Bruce, M. I.; Hameister, C.; Swincer, A. G.; Wallis, R. C. Inorg.
Synth. 1982, 21, 78.
(19) Fagan, P. J .; Ward, M. D.; Calabrese, J . C. J . Am. Chem. Soc.
1989, 111, 1716.
Yield: ca. 70%, for both methods. Anal. Calcd for C82H110
-
B2P4Ru2S2: C, 65.3; H, 7.35; S, 4.25. Found: C, 64.9; H, 7.25;
S, 4.1. UV/vis (CH2Cl2 solution, λmax, nm (ꢀ, M-1 cm-1)): 766-
(10000), 360(6500). NMR (SO(CD3)2) δ: (1H) 1.01 (m, PCH2-
CH3); 1.77 (m, PCH2CH3); 5.00 (s, C5H5). 31P{1H}: 28.5 (s).
13C{1H}: 8.3 (s, P(CH2CH3)3); 21.4 (t, J (C,P) ) 13.7 Hz, P(CH2-
CH3)3); 80.2 (s, C5H5).

4394 Organometallics, Vol. 17, No. 20, 1998
Coto et al.
[{Cp Ru (P P h 3)(P iP r 2Me)}2(µ-S2)][BP h 4]2 (5). Any of the
two experimental procedures described for the preparation of
4 were followed for the synthesis of this compound, starting
from 2 (0.18 g, 0.3 mmol). Yield: 66-70%, for both methods.
Anal. Calcd for C108H114B2P4Ru2S2: C, 71.1; H, 6.26; S, 3.52.
) 13.3 Hz, P(CH2CH3)3); 77.6 (s, C5H5); 114.9, 128.9, 137.4,
137.5, 173.1 (s, RuSC5H4NH).
[Cp Ru (SNC5H5)(P P h 3)(P iP r 2Me)][BP h 4] (9). An experi-
mental procedure identical to that for 8 was followed for the
preparation of this compound, starting from 2 (0.18 g, 0.3
mmol). Yield: 80%. Anal. Calcd for C59H62BNP2RuS: C, 71.5;
H, 6.31; N, 1.41; S, 3.24. Found: C, 71.8; H, 6.36; N, 1.5; S,
3.1. IR: ν(NH) 3208 cm-1. NMR (CD3COCD3) δ: (1H) 0.27
(d, PCH3), 0.81, 1.12, 120 (m, P(CH(CH3)2), 1.92 (dm, P(CH-
(CH3)2), 4.72 (s, C5H5); 5.95 (m), 6.11 (t), 6.88, 7.37 (d),
RuSC5H4NH; 7.28, 7.30 (m, P(C6H5)3); 9.85 (s br, RuSC5H4NH).
31P{1H}: 44.4 d; 33.7 d, J (P,P) ) 38.5 Hz. 13C{1H}: 0.17 (d,
J (C,P) ) 11.1 Hz, PCH3); 17.3 s, 18.6 s, 18.9 s, 19.3 (d, J (C,P)
) 4.8 Hz), PCH(CH3)2); 31.0 (dd, 1J (C,P) ) 23.5 Hz, 3J (C,P) )
2.5, PCH(CH3)2); 32.0 (dd, 1J (C,P) ) 24.8 Hz, 3J (C,P) ) 3.4
Hz, PCH(CH3)2); 81.7 (s, C5H5); 115.2, 135.7, 137.0, 137.5, 173.1
(s, RuSC5H4NH); 128.7 (s), 133.9 (d, J (C,P) ) 9.80 Hz), 130.6
(s), P(C6H5).
Found: C, 70.8; H, 6.11; S, 3.4. UV/vis (CH2Cl2 solution, λmax
,
nm (ꢀ, M-1 cm-1)): 775(18000), 355(8600). NMR (CD3COCD3)
δ: (1H) 1.01 (m, P(CH3(CH(CH3)2)2)); 1.16, 1.27 (m, P(CH3(CH-
(CH3)2)2)); 2.42 (m, P(CH3(CH(CH3)2)2)); 4.33 (s, C5H5); 7.17,
7.60 (m, P(C6H5)3). 31P{1H}: 45.0 d, 38.6 d, J (P,P) ) 40.9 Hz.
13C{1H}: 2.3 (s, P(CH3(CH(CH3)2)2)); 17.2, 18.1, 18.3, 19.4 (s,
P(CH3(CH(CH3)2)2)); 80.7 (t, J (C,P) ) 2.2 Hz, C5H5); 124.1,
126.3, 133.9 (s, PC6H5).
[{Cp *R u (P E t3)2}2(µ-S2)][BP h 4]2 (6). Met h od A (fr om
H2S). To a suspension of 3 (0.16 g, 0.3 mmol) in EtOH (20
mL) was added an excess of NaBPh4 (ca. 0.3 g), and then H2S
was bubbled through the stirred mixture at room temperature
for 2-3 min. A mustard yellow precipitate was formed
initially. Air was then admitted into the reaction mixture, and
it was stirred for 24 h at room temperature. During this time,
the mixture turned green. It was filtered, and the resulting
green solution concentrated. Cooling to -20 °C afforded green
microcrystals, which were filtered off, washed with EtOH and
petroleum ether, and dried in vacuo.
Meth od B (fr om Elem en ta l Su lfu r ). A suspension of 3
(0.25 g, 0.5 mmol) in MeOH was treated with the stoichiomet-
ric amount of elemental sulfur (0.016 g, ca. 0.5 mmol) and an
excess of NaBPh4 (0.3 g), and the mixture stirred overnight.
A green, microcrystalline precipitate was obtained, which was
filtered off, washed with EtOH and petroleum ether, and dried.
Another crop was obtained from the mother liquor by concen-
tration and cooling to -20 °C.
This material was recrystallized from acetone/EtOH or CH2-
Cl2/EtOH mixtures, in the form of green needles. Yield: 45-
55% for both methods. Anal. Calcd for C92H130B2P4Ru2S2: C,
67.1; H, 7.95; S, 3.9. Found: C, 67.0; H, 8.03; S, 3.7. UV/vis
(CH2Cl2 solution,λmax, nm (ꢀ, M-1 cm-1)): 744(6500), 398(3900).
NMR (CD3COCD3) δ: (1H) 1.07 (m, PCH2CH3); 1.84 (s,
C5(CH3)5); 2.05 (dm, PCH2CH3). 31P{1H}: 21.2 (s). 13C{1H}:
10.1 (s, C5(CH3)5); 10.6 (s, P(CH2CH3)3); 21.2 (t, J (C,P) ) 13.7
Hz, P(CH2CH3)3); 102.8 (s, C5(CH3)5).
[Cp *Ru (SNC5H5)(P Et3)2][BP h 4] (10). 10 was obtained in
a fashion analogous to that for 8, starting from 3 (0.16 g, 0.3
mmol). Yield: 0.22 g, 80%. Anal. Calcd for C51H70BNP2-
RuS: C, 67.8; H, 7.76; N, 1.55; S, 3.54. Found: C, 67.9; H,
7.64; N, 1.2; S, 3.2. NMR (CD3COCD3) δ: (1H) 1.13 (m,
PCH2CH3), 1.97 (dm, PCH2CH3), 1.72 (t, J (H,P) ) 1 Hz, C5-
(CH3)5); 7.04 (t), 7.66 (d), 7.73 (d), 8.18 (t); 12.27 (s br, NH).
31P{1H}: 18.2 (s). 13C{1H}: 9.8 (s, P(CH2CH3)3); 11.0 (s, C5-
(CH3)5); 21.6 (t, J (C,P) ) 12.4 Hz, P(CH2CH3)3); 83.8 (s, C5-
(CH3)5); 116.2, 131.3, 138.6, 139.0 (s, RuSC5H4NH).
[Cp Ru (S2COR)(P iP r 2Me)] (R ) Me 11a , Et 11b, iP r 11c).
To a solution of 2 (0.18 g, 0.3 mmol) in acetone (15 mL) was
added the stoichiometric amount of the corresponding potas-
sium alkylxanthate KS2COR. The resulting suspension was
heated under reflux for 7 h. Then, the solvent was removed
in vacuo, the residue extracted with petroleum ether, and the
resulting red solution filtered through Celite. Concentration
and cooling to -20 °C afforded red crystals, which were filtered
off and dried. The compounds were recrystallized from
petroleum ether to remove any traces of free PPh3. Yield: ca.
70% in all cases. 11a : Anal. Calcd for C14H25OPRuS2: C, 41.5;
H, 6.21; S, 15.81. Found: C, 41.2; H, 6.41; S, 15.9. IR: ν(CS)
1172, 1042 cm-1
.
NMR (C6D6) δ: (1H) 0.77 (d, PCH3), 0.95
(m, PCH(CH3)2), 1.68 (sept, PCH(CH3)2); 3.58 (s, OCH3); 4.43
(s, C5H5). 31P{1H}: 50.83 (s). 13C{1H}: -1.61 (d, J (C,P) ) 21.4
Hz PCH3); 18.0, 18.9 (s, PCH(CH3)2); 29.8 (d, J (C,P) ) 24.8
Hz, PCH(CH3)2); 55.7 (s, OCH3); 73.6 (d, J (C,P) ) 2.6 Hz,
C5H5); 226.5 (d, 3J (C,P) ) 6 Hz, S2CO). 11b: Anal. Calcd for
[Cp *Ru H(SH)(P Et3)2][BP h 4] (7). H2S was bubbled for
2-3 min through a solution of 3 (0.16 g, 0.3 mmol) in EtOH
(20 mL) containing an excess of NaBPh4 (ca. 0.3 g). Almost
immediately, a mustard yellow precipitate was formed. The
mixture was stirred for 15 min, and then the solids were
filtered off, washed with EtOH and petroleum ether, and dried
in vacuo. Yellow single crystals suitable for X-ray structure
analysis were obtained by layering with EtOH a concentrated
acetone solution of this compound, with careful oxygen exclu-
sion in order to avoid the formation of the binuclear persulfide
6. Yield: 0.14 g, 57%. Anal. Calcd for C46H67BP2RuS: C,
66.9; H, 8.18; S, 3.9. Found: C, 67.2; H, 8.33; S, 3.8. IR: ν-
(SH) 2670 cm-1, weak; ν(RuH) 2049 cm-1, weak. NMR (CD3-
COCD3) δ: (1H) -9.67 (t, J (H,P) ) 35 Hz RuH); -2.79 (t,
J (H,P) ) 8.4 Hz, RuSH); 1.21 (m, PCH2CH3); 1.57 (s, C5(CH3)5);
2.01 (dm, PCH2CH3). 31P{1H}: 31.7 (s). 13C{1H}, (CDCl3): 8.9
(s, P(CH2CH3)3); 10.1 (s, C5(CH3)5); 19.5 (t, J (C,P) ) 29.6 Hz
P(CH2CH3)3); 103.2 (s, C5(CH3)5).
C
15H27OPRuS2: C, 42.9; H, 6.49; S, 15.3. Found C, 42.6; H,
6.50; S, 14.9. IR: ν(CS) 1216, 1029 cm-1. NMR (C6D6) δ: (1H)
0.81 (d, PCH3); 0.96 (t, OCH2CH3); 0.95 (m, PCH(CH3)2), 1.68
(sept, PCH(CH3)2); 4.24 (quartet, OCH2CH3); 4.45 (s, C5H5).
31P{1H}: 51.2 (s). 13C{1H}: -2.32 (d, J (C,P) ) 20.5 Hz, PCH3);
13.2 (s, OCH2CH3); 17.2, 18.2 (s, PCH(CH3)2); 29.0 (d, J (C,P)
) 24.8 Hz, (PCH(CH3)2); 64.7 (s, OCH2CH3); 72.8 (d, J (C,P) )
3
2.6 Hz, C5H5); 226.2 (d, J (C,P) ) 5.3 Hz, S2CO). 11c: Anal.
Calcd for C16H29OPRuS2: C, 44.3; H, 6.74; S, 14.7. Found C,
44.0; H, 6.64; S, 14.4. IR: ν(CS) 1215, 1098 cm-1. NMR (C6D6)
δ: (1H) 0.81 (d, PCH3); 0.96 (d, OCH(CH3)2); 0.95 (m, PCH-
(CH3)2); 1.67 (sept, PCH(CH3)2); 4.24 (sept, OCH(CH3)2); 4.45
(s, C5H5). 31P{1H}: 51.2 (s). 13C{1H}: -1.5 (d, J (C,P) ) 20.5
Hz, P(CH3)); 14.0 (s, OCH(CH3)2); 18.0, 19.0 (s, PCH(CH3)2);
29.9 (d, J (C,P) ) 24.8 Hz, PCH(CH3)2); 65.5 (s, OCH(CH3)2);
73.6 (d, J (C,P) ) 1.7 Hz, C5H5); 226.2 (d, 3J (C,P) ) 6 Hz, S2CO).
[Cp Ru (SNC5H5)(P Et3)2][BP h 4] (8). To a solution of 1
(0.13 g, 0.3 mmol) in EtOH (20 mL) was added a slight excess
of 2-mercaptopyridine (0.04 g, ca. 0.35 mmol). Then, an excess
of NaBPh4 (ca. 0.3 g) was added, and the mixture stirred for
15 min. The microcrystalline precipitate was filtered off,
washed with EtOH and petroleum ether, and dried in vacuo.
Yield: 0.2 g, 80%. Anal. Calcd for C46H60BNP2RuS: C, 66.3;
H, 7.26; N, 1.68; S, 3.85. Found: C, 65.9; H, 7.32; N, 1.7; S,
i
[Cp *Ru (S2COR)(P Et3)] (R ) Me 12a , Et 12b, P r 12c).
An experimental procedure identical to that for 11a -c was
followed for the preparation of these complexes, starting from
3 (0.16 g, 0.3 mmol), although purification by recrystallization
to achieve the removal of free PPh3 was obviously not required.
3.8. IR: ν(NH) 3229 cm-1
.
NMR (CDCl3) δ: (1H) 1.02 (m,
Yield: ca. 70% in all cases. 12a : Anal. Calcd for C18H33-
PCH2CH3), 1.75 (dm, PCH2CH3), 4.62 (s, C5H5); 6.07 (d), 6.19
(t), 6.89 (t), 7.30 (d), RuSC5H4NH; 10.04 (s br, RuSC5H4NH).
31P{1H}: 28.2 (s). 13C{1H}: 8.5 (s, P(CH2CH3)3); 22.0 (t, J (C,P)
OPRuS2: C, 46.8; H, 7.16; S, 13.9. Found: C, 46.8; H, 7.29;
S, 13.6. IR: ν(CS) 1216, 1046 cm-1. NMR (C6D6) δ: (1H) 0.90
(dt, PCH2CH3); 1.60 (dq, PCH2CH3); 1.71 (s, C5(CH3)5); 3.63

Half-Sandwich Ruthenium Phosphine Complexes
Organometallics, Vol. 17, No. 20, 1998 4395
(s, OCH3). 31P{1H}: 32.9 (s). 13C{1H}: 7.9 (s, P(CH2CH3)3);
10.9 (s, C5(CH3)5); 15.7 (d, J (C,P) ) 22.2 Hz, P(CH2CH3)3); 55.9
(s, OCH3); 84.1 (d, J (C,P) ) 2.6 Hz, C5(CH3)5); 228.4 (d, 3J (C,P)
) 6.8 Hz, S2CO). 12b: Anal. Calcd for C19H35OPRuS2: C, 48.0;
H, 7.42; S, 13.5. Found: C, 48.1; H, 7.26; S, 13.2. IR: ν(CS)
Ta ble 1. Su m m a r y of Da ta for th e Cr ysta l
Str u ctu r e An a lysis of 7 a n d 12c
7
12c
formula
C
46H67BP2RuS
C20H37OPRuS2
489.68
fw
825.88
1172, 1051 cm-1
.
NMR (C6D6) δ: (1H) 0.92 (dt, PCH2CH3);
crystal size (mm)
crystal system
space group
cell parameters
0.12 × 0.15 × 0.32 0.35 × 0.23 × 0.40
1.00 (t, OCH2CH3); 1.62 (dq, PCH2CH3); 1.73 (d, J (H,P) ) 1.2
Hz C5(CH3)5); 4.28 (q, OCH2CH3). 31P{1H}: 33.1 (s). 13C{1H}:
7.9 (s, P(CH2CH3)3); 10.9 (s, C5(CH3)5); 14.0 (s, OCH2CH3); 15.8
(d, J (C,P) ) 22.2 Hz, P(CH2CH3)3); 65.6 (OCH2CH3); 84.1 (d,
orthorhombic
triclinic
P212121 (No. 19)
a ) 16.042(3) Å
b ) 20.451(5) Å
c ) 13.282(4) Å
P-1 (No. 2)
a ) 8.884(6) Å
b ) 15.960(8) Å
c ) 8.711(6) Å
R ) 91.66(5)°
â ) 104.95(5)°
γ ) 87.65(5)°
1192(2)
3
J (C,P) ) 1.7 Hz, C5(CH3)5); 229.8 (d, J (C,P) ) 6 Hz, S2CO).
12c: Anal. Calcd for C20H37OPRuS2: C, 49.1; H, 7.62; S, 13.1.
Found: C, 48.9; H, 7.80; S, 12.9. IR: ν(CS) 1178, 1019 cm-1
.
NMR (C6D6) δ: (1H) 0.91 (dt, PCH2CH3); 1.14 (d, OCH(CH3)2);
1.63 (dq, PCH2CH3); 1.74 (d, J (H,P) ) 1.2 Hz C5(CH3)5); 5.43
(septet, OCH(CH3)2). 31P{1H}: 33.5 (s). 13C{1H}: 7.9 (s,
PCH2CH3); 10.9 (s, C5(CH3)5); 15.9 (d, J (C,P) ) 22.1 Hz, PCH2-
CH3); 21.7 (s, OCH(CH3)2); 73.5 (s, OCH(CH3)2); 84.2 (s, C5-
(CH3)5); S2CO not observed.
volume
4358(2) Å3
4
Z
Fcalcd
2
1.251 g cm-3
0.71069 Å
4.99 cm-1
1732
1.364 g cm-3
0.71069 Å
8.85 cm-1
512
λ(Mo KR)
µ(Mo KR)
F(000)
transmision factors
scan speed (ω)
2θ interval
no. of measd reflns
no. of unique reflns
no. of obsd reflns
no. of params
0.94-1.00
4° min-1
5° < 2θ < 50.1°
3680
3539
1841 (I > 2σI)
229
0.76-1.00
4° min-1
5° < 2θ < 50.1°
4095
3853
3253 (I > 3σI)
226
i
[Cp Ru (S2COR)(P Et3)2] (R ) Me 13a , Et 13b, P r 13c).
An experimental procedure identical to that for 11a -c was
followed for the preparation of these complexes, starting from
1 (0.13 g, 0.3 mmol) and using EtOH (20 mL) as solvent instead
of acetone. Yield: ca. 75% in all cases. 13a : Anal. Calcd for
C
19H38OP2RuS2: C, 44.8; H, 7.52; S, 12.6. Found: C, 44.6; H,
reflection/parameter ratio 8.04
14.39
7.44; S, 12.4. IR: ν(CS) 1183, 1045 cm-1. NMR (C6D6) δ: (1H)
0.78 (m, PCH2CH3); 1.47 (dm, PCH2CH3); 4.09 (s, OCH3); 4.63
(s, C5H5). 31P{1H}: 31.9 (s). 13C{1H}: 8.3 (s, P(CH2CH3)3); 21.7
(t, J (C,P) ) 13.1 Hz, P(CH2CH3)3); 58.5 (s, OCH3); 79.8 (s,
Ra
0.076
0.088
4.52
0.041
0.051
2.77
1.98
-2
b
Rw (w ) σF
)
max ∆/σ in final cycle
GOF
1.98
3
C5H5); 228.9 (t, J (C,P) ) 6 Hz, S2CO). 13b: Anal. Calcd for
a
b
2
R ) ∑||Fo| - |Fc||/∑|Fo|. Rw ) (∑w(|Fo| - |Fc|)2/∑w|Fo| ).1/2
C
20H40OP2RuS2: C, 45.9; H, 7.70; S, 12.2. Found: C, 45.9; H,
7.80; S, 11.9. IR: ν(CS) 1184, 1040 cm-1. NMR (C6D6) δ: (1H)
0.77 (m, PCH2CH3); 1.23 (t, 7.0 Hz, OCH2CH3); 1.46 (dm, PCH2-
CH3); 4.65 (s, C5H5); 4.76 (q, OCH2CH3). 31P{1H}: 31.9 (s).
13C{1H} (CDCl3): 8.3 (s, P(CH2CH3)3); 14.5 (s, OCH2CH3); 21.6
(t, J (C,P) ) 13.3 Hz, P(CH2CH3)3); 68.5 (s, OCH2CH3); 79.1 (s,
11.9 (s, C5(CH3)5); 16.3 (d, J (C,P) ) 21.4 Hz, PCH2CH3); 42.8,
49.1 (s, N(CH2CH3)2); 83.8 (d, J (C,P) ) 3.5 Hz, C5(CH3)5).
[Cp Ru (S2CNEt2)(P Et3)2] (16). 16 was obtained in the
form of orange crystals following a procedure identical to that
for 14, starting from 1 (0.11 g, 0.25 mmol). Yield: 0.11 g, 80%.
Anal. Calcd for C22H45NP2RuS2: C, 48.0; H, 8.24; N, 2.5; S,
11.6. Found: C, 47.8; H, 8.11; N, 2.63; S, 11.5. IR: ν(CdN)
1481 cm-1. NMR (C6D6) δ: (1H) 0.68 (t, NCH2CH3); 0.92 (m,
PCH2CH3); 1.57 (dm, PCH2CH3); 3.01, 3.61 (m, N(CH2CH3)2);
4.38 (s, C5H5). 31P{1H}: 32.7 (s). 13C{1H}: 8.3 (s, PCH2CH3);
11.5, 12.3 (s, N(CH2CH3)2); 21.2 (t, J (C,P) ) 12.4 Hz, PCH2-
CH3); 46.5, 49.6 (s, N(CH2CH3)2); 76.9 (t, J (C,P) ) 2.6 Hz,
C5H5).
3
C5H5); 229.5 (t, J (C,P) ) 6 Hz, S2CO). 13c: Anal. Calcd for
C
21H42OP2RuS2: C, 46.9; H, 7.87; S, 11.9. Found: C, 46.6; H,
8.10; S, 11.7. IR: ν(CS) 1187, 1020 cm-1. NMR (C6D6) δ: (1H)
0.77 (m, PCH2CH3); 1.33 (d, OCH(CH3)2); 1.45 (dm, PCH2CH3);
4.65 (s, C5H5); 6.21 (septet, OCH(CH3)2). 31P{1H}: 31.9 (s).
13C{1H}: 8.4 (s, P(CH2CH3)3); 22.0 (t, J (C,P) ) 12.4 Hz, P(CH2-
CH3)3); 22.6 (s, OCH(CH3)2); 74.9 (s, OCH(CH3)2); 79.7 (s,
3
C5H5); 227.7 (t, J (C,P) ) 6 Hz, S2CO).
[Cp Ru (S2CNEt2)(P iP r 2Me)] (14). A solution of 2 (0.15 g,
0.25 mmol) in acetone (15 mL) was treated with sodium
diethyldithiocarbamate (0.25 mmol), and the resulting suspen-
sion heated under reflux for 7 h. The solvent was removed in
vacuo and the residue was extracted with petroleum ether and
filtered through Celite. Concentration and cooling to -20 °C
afforded red-brown crystals, which were recrystallized from
petroleum ether in order to remove traces of free PPh3.
Yield: 80%. Anal. Calcd for C17H32NPRuS2: C, 45.7; H, 7.22;
N, 3.1; S, 14.4. Found: C, 45.9; H, 7.11; N 3.1; S, 14.6. IR:
ν(CdN) 1457 cm-1. NMR (CDCl3) δ: (1H) 0.90 (t, N(CH2CH3)2);
1.05 (d, PCH3); 1.07 (m, PCH(CH3)2); 3.24, 3.40 (m, NCH2CH3);
1.87 (septet, PCH(CH3)2); 4.35 (s, C5H5). 31P{1H}: 52.09 (s).
13C{1H}: -1.05 (d, J (C,P) ) 5.6 Hz, PCH3); 12.7 (s, N(CH2CH3)2);
18.2, 19.1 (s, PCH(CH3)2); 30.2 (d, J (C,P) ) 23.2 Hz, PCH-
(CH3)2); 42.54, 42.76 (s, N(CH2CH3)2); 73.9 (d, J (C,P) ) 1.7 Hz,
C5H5).
E xp er im en t a l Da t a for t h e X-r a y Cr yst a l St r u ct u r e
Deter m in a tion s. Crystals suitable for X-ray diffraction
analysis were mounted onto a glass fiber and transferred to
an AFC6S-Rigaku automatic diffractometer (T ) 290 K, Mo
KR radiation, graphite monochromator, λ ) 0.710 73 Å).
Accurate unit cell parameters and an orientation matrix in
each case were determined by least-squares fitting from the
settings of 25 high-angle reflections. Crystal data and details
on data collection and refinements are given in Table 1. Data
were collected by the ω-2θ scan method in both cases. Lorentz
and polarization corrections were applied. Decay was moni-
tored by measuring three standard reflections every 100
measurements. Decay and semiempirical absorption correc-
tion (ψ method) were also applied.
The structures were solved by Patterson methods and
subsequent expansion of the models using DIRDIF.20 Reflec-
tions having I > 2σ(I) in the case of complex 7 or I > 3σ(I) in
the case of complex 12c were used for structure refinement.
For 7, Ru, S, and P atoms were anisotropically refined, and
the remaining non-H atoms were isotropically refined. Some
disorder was detected in ethyl groups, and C(20) was refined
in two positions with complementary population factors. H-
(1) and H(2) were localized in difference Fourier maps, and
[Cp *Ru (S2CNEt2)(P Et3)] (15). Brown crystals of 15 were
obtained in a fashion analogous to that for 14, starting from
3 (0.13 g, 0.25 mmol) and omitting the separation from free
PPh3. Yield: 0.1 g, 80%. Anal. Calcd for C21H40NPRuS2: C,
50.2; H, 8.02; N, 2.8; S, 12.7. Found: C, 50.0; H, 8.00; N, 2.9;
S, 12.5. IR: ν(CdN) 1478 cm-1. NMR (C6D6) δ: (1H) 0.95 (t,
NCH2CH3); 0.99 (dt, PCH2CH3); 1.78 (dq, PCH2CH3); 1.82 (t,
J (H,P) ) 1 Hz, C5(CH3)5); 3.31, 3.43 (m, NCH2CH3). 31P{1H};
33.8 (s). 13C{1H}: 8.1 (s, PCH2CH3); 10.9, 12.6 (s, N(CH2CH3)2);
(20) Beurkens, P. T. DIRDIF, Technical Report 1984/1; Crystal-
lography Laboratory: Toernooiveld, 6525 Ed Nijmegen, Netherlands.

4396 Organometallics, Vol. 17, No. 20, 1998
Coto et al.
the remaining H atoms included at idealized positions. For
12c all non-H atoms were anisotropically refined, and the H
atoms were included at idealized positions. H atoms were not
refined. All calculations for data reduction, structure solution,
and refinement were carried out on a VAX 3520 computer at
the Servicio Central de Ciencia y Tecnolog´ıa de la Universidad
de Ca´diz, using the TEXSAN21 software system and ORTEP22
for plotting. Maximum and minimum peaks in the final
-3
difference Fourier maps were +1.01 and -0.61 e Å
for 7
and +1.01 and -1.15 e Å-3 for 12c.
Resu lts a n d Discu ssion
The complexes [CpRuCl(PEt3)2] (1) and [CpRuCl-
(PPh3)(PMeiPr2)] (2) react with H2S in EtOH in the
presence of NaBPh4 furnishing the deep green persul-
fido complexes [{CpRu(PEt3)2}2(µ-S2)][BPh4]2 (4) and
[{CpRu(PPh3)(PMeiPr2)}2(µ-S2)][BPh4]2 (5), respectively.
These compounds are also accessible by reaction of 1 or
2 with the stoichiometric amount of elemental sulfur
and an excess of NaBPh4 in MeOH, a procedure devel-
oped by Rauchfuss and co-workers for the preparation
of a range of binuclear half-sandwich persulfide com-
plexes of ruthenium.23 The spectral properties of 4 and
5 match those reported for the complexes [{CpRu(L)2}2-
(µ-S2)]2+ (Cp ) C5H5, C5H4Me; L ) PPh3, PMe3),23
including the presence of a strong charge-transfer band
near 750 nm in the visible spectrum, ascribed to
transitions involving the Ru2S2 core and responsible for
the intense green color displayed by these compounds.24
On these grounds, the structure of these persulfide
complexes is probably analogous to that found by X-ray
crystallography for [{CpRu(PMe3)2}2(µ-S2)][SbF6]2‚2 C6H5-
NO2, which consists of a centrosymmetrical arrange-
ment of {CpRu(PMe3)2} moieties linked by a persulfido
unit.23
F igu r e 1. ORTEP drawing of the cation [Cp*RuH(SH)-
(PEt3)2]+ with 50% probability thermal ellipsoids. H atoms,
except hydride and that on the mercapto ligand, are
omitted.
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [Cp *Ru H(SH)(P Et3)2][BP h 4] (7) w ith
Estim a ted Sta n d a r d Devia tion s in P a r en th eses
Ru(1)-S(1)
Ru(1)-P(1)
Ru(1)-P(2)
Ru(1)-C(1)
Ru(1)-C(2)
2.411(6)
2.341(6)
2.334(7)
2.35(3)
Ru(1)-C(3)
Ru(1)-C(4)
Ru(1)-C(5)
Ru(1)-H(1)
S(1)-H(2)
2.31(3)
2.34(3)
2.37(3)
1.50
2.37(2)
1.56
S(1)-Ru(1)-P(1)
S(1)-Ru(1)-P(2)
S(1)-Ru(1)-C(1)
S(1)-Ru(1)-C(2)
S(1)-Ru(1)-C(3)
S(1)-Ru(1)-C(4)
S(1)-Ru(1)-C(5)
P(1)-Ru(1)-P(2)
P(1)-Ru(1)-C(1)
P(1)-Ru(1)-C(2)
P(1)-Ru(1)-C(3)
83.0(3)
83.4(3)
90.1(7)
119.4(6)
145.6(6)
120.4(7)
87.9(7)
107.5(2)
107.2(7)
93.6(7)
P(1)-Ru(1)-C(4)
P(1)-Ru(1)-C(5)
P(2)-Ru(1)-C(1)
P(2)-Ru(1)-C(2)
P(2)-Ru(1)-C(3)
P(2)-Ru(1)-C(4)
P(2)-Ru(1)-C(5)
S(1)-Ru(1)-H(1)
P(1)-Ru(1)-H(1)
P(2)-Ru(1)-H(1)
Ru(1)-S(1)-H(2)
150.1(7)
144.0(7)
143.6(7)
151.2(6)
118.6(7)
94.4(7)
105.9(7)
131.33
66.40
71.96
123.97
The reaction of the pentamethylcyclopentadienyl
derivative [Cp*RuCl(PEt3)2] (3) with elemental sulfur
and NaBPh4 in MeOH also yielded, as expected, the
binuclear persulfido complex [{Cp*Ru(PEt3)2}2(µ-S2)]-
[BPh4]2 (6). However, the direct reaction of 3 with H2S
followed a different course. Thus, when H2S was
bubbled through a slurry of 3 in EtOH containing an
excess of NaBPh4, a mustard yellow precipitate was
immediately obtained, which upon isolation turned to
be the RuIV hydrido-metallothiol complex [Cp*RuH(SH)-
(PEt3)2][BPh4] (7). This compound is diamagnetic, as
inferred from NMR data, and shows weak ν(SH) and
ν(RuH) bands at 2670 and 2049 cm-1 in its IR spectrum.
The resonances for the hydrido and mercapto protons
appear as triplets at -9.67 ppm (2J (H,P) ) 35 Hz) and
111.5(6)
around ruthenium can be described as a four-legged
piano stool structure. The hydride and mercapto ligands
are in mutually transoid positions, with an H(1)-Ru-
S(1) angle of 131.33°. The phosphines also adopt a
transoid disposition with a P(1)-Ru-P(2) angle of
107.5(2)°. The ruthenium-hydride bond distance Ru-
H(1) 1.50 Å is in the normal range previously observed
in other ruthenium hydride complexes.25 The Ru-S(1)
separation 2.411(6) Å is slightly shorter than in [Ru-
(SH)2(CO)2(PPh3)2] (2.472(2) and 2.470(2) Å),5 possibly
due to the fact that in the latter complex the mercapto
groups are trans to strong π-acceptor CO ligands, but
other ruthenium complexes with thiolato ligands show
Ru-S separations in the range 2.40-2.43 Å,26 fully
consistent with the value observed by us. The hydrogen
atom attached to sulfur was located in a difference
Fourier map but not refined, resulting in a S(1)-H(2)
bond distance of 1.56 Å and a Ru-S(1)-H(2) angle of
123.97°. This S-H bond length is longer than found in
gaseous H2S (1.33 Å) and also in the reported terminal
mercapto complexes with located protons (1.2-1.4 Å),
the Ru-S(1)-H(2) angle being also larger than in other
1
-2.79 ppm (3J (H,P) ) 8.4 Hz), respectively, in the H
NMR spectrum, whereas the 31P{1H} NMR spectrum
consists of one singlet. These spectral data suggest a
four-legged piano stool structure for the complex cation.
This was unequivocally established by X-ray crystal
structure analysis. An ORTEP view of [Cp*RuH(SH)-
(PEt3)2]+ is shown in Figure 1. Selected bond lengths
and angles are listed in Table 2. The coordination
(21) TEXSAN, Single-Crystal Structure Analysis Software, version
5.0; Molecular Structure Corp.: The Woodlands, TX, 1989.
(22) J ohnson, C. K. ORTEP, A Thermal Ellipsoid Plotting Program;
Oak Ridge National Laboratory: Oak Ridge, TN, 1965.
(23) Amarasekara, J .; Rauchfuss, T. B.; Wilson, S. R. Inorg. Chem.
1987, 26, 3328.
(25) J ime´nez-Tenorio, M.; Puerta, M. C.; Valerga, P. Inorg. Chem.
1994, 33, 3515. Bianchini, C.; Frediani, P.; Masi, D.; Peruzzini, M.;
Zanobini, F. Organometallics 1994, 13, 4616. Lemke, F. R.; Brammer,
L. Organometallics 1995, 14, 3980.
(24) Kin, S.; Otterbein, E. S.; Rava, R. P.; Isied, S. S.; San Filippo,
J ., J r.; Waszcyak, J . V. J . Am. Chem. Soc. 1983, 105, 336.
(26) Field, L. D.; Hambley, T. W.; Yau, B. C. K. Inorg. Chem. 1994,
33, 2009.

Half-Sandwich Ruthenium Phosphine Complexes
Organometallics, Vol. 17, No. 20, 1998 4397
Sch em e 1. P r op osed Rea ction Sequ en ce for th e
F or m a tion of th e Bin u clea r P er su lfid e Com p lex 6
a t th e Exp en se of th e Hyd r id o-Meta lloth iol 7
complexes (usually less than 100°), although approach-
ing those in [Cp*Ti(SH)2] (106° and 116°).27 It has been
suggested that more electropositive atoms, such as TiIV,
attached to sulfur cause wider angles at the S,5 an
observation consistent with the fact that compound 7
contains a ruthenium atom in the high formal oxidation
state +4. The C5 ring of the C5Me5 ligand is planar,
and the plane defined by the C5Me5 centroid, the
hydride, S(1), and the metal atom is nearly normal to
the C5 ring, an arrangement that has been previously
observed in other half-sandwich RuIV complexes such
as [Cp*Ru(H)2(dippe)][BPh4]28 and [Cp*RuH(Ct
CCOOMe)(dippe)][BPh4] (dippe ) 1,2-bis(diisopropy-
lphosphino)ethane).29 All the other bond lengths and
angles found in the ligands and in the [BPh4]- anion
are in the usual range.
Although oxidative addition of H2S to transition metal
complexes is well established,5,8,14,15 this is the first case,
as far as we are aware, in which the formal oxidation
from RuII to RuIV has been observed. This process
resembles the oxidative addition of H2 to [CpRu(PR3)2]+
fragments to yield the corresponding RuIV dihydrides
[CpRu(H)2(PR3)2]+ 28 or even the recently reported oxi-
dative addition of 1-alkynes to [Cp*Ru(dippe)]+ to
furnish RuIV hydrido-alkynyl complexes [Cp*RuH(Ct
CR)(dippe)]+, intermediates in the formation of the
corresponding vinylidene derivatives [Cp*RudCdCHR-
(dippe)]+.29 Once more, the differences between cyclo-
pentadienyl ruthenium complexes and their pentameth-
ylcyclopentadienyl analogues become apparent, since no
hydrido-metallothiol complexes have been observed in
the course of the reaction of 1 or 2 with H2S. Penta-
methylcyclopentadienyl ruthenium complexes contain
metal centers that are more electron-rich than those in
its cyclopentadienyl counterparts, owing to the in-
creased electron-releasing capabilities of the C5Me5 in
comparison with C5H5.
Compound 7 is slowly oxidized in solution by atmo-
spheric oxygen to yield the green persulfido complex 6,
with concomitant formation of water. In fact, if a slurry
of 7 in MeOH or EtOH is stirred overnight in air at room
temperature, it gradually turns green, and finally 6 is
obtained. Compound 6 is also recovered in poor yields
from the mother liquor of the reaction of 3 with H2S in
EtOH. We can tentatively propose the reaction se-
quence shown in Scheme 1 to explain the formation of
6 at the expense of 7. The hydrido-metallothiol complex
7 is possibly in equilibrium with the neutral mercapto
derivative [Cp*Ru(SH)(PEt3)2], as a result of a depro-
tonation/reprotonation process. Since neutral mercapto
complexes of ruthenium such as [CpRu(SH)(PPh3)2] are
known to undergo easy oxidation to yield the corre-
sponding binuclear persulfido derivatives,10 this may
also happen in our case even at trace level concentra-
tions of O2. Another feasible pathway should involve
protonation of the putative mercapto complex at the lone
pair of sulfur to give the H2S adduct [Cp*Ru(SH2)-
(PEt3)2]+, which according to data in the literature
should be an unstable species easily oxidizable to the
corresponding persulfido species 6.10,12 Experimental
evidence supporting the occurrence of a deprotonation/
reprotonation equilibrium comes from the observation
that the hydride ligand readily exchanges with deute-
rium when D2O is added to an acetone solution of 7,
furnishing the isotopomer [Cp*RuD(SH)(PEt3)2]+ as
inferred from NMR spectroscopy. Under these condi-
tions, no deuterium exchange with the mercapto proton
is observed, at variance with what happens in the case
of [RuH(SH)(CO)2(PPh3)2], for which the exchange at the
hydride occurs more slowly than that at the mercapto
moiety.5 This difference is possibly due to the fact that
compound 7 is relatively acidic due to its cationic nature
and also because it contains RuIV, whereas [RuH(SH)-
(CO)2(PPh3)2] is a neutral RuII derivative, with fairly
basic properties.5 Although the reaction sequence shown
in Scheme 1 seems reasonable, it must be regarded with
due caution, since attempts made to isolate the neutral
mercapto complex [Cp*Ru(SH)(PEt3)2] have been so far
unsuccessful, and no direct spectral evidence could be
obtained for this intermediate. Accordingly, other pos-
sible reaction pathways cannot be ruled out.
The reaction of half-sandwich ruthenium complexes
with organic thiols has been reported to produce thiolate
complexes, or even thiol derivatives,30 i.e., [CpRu-
(HSBut)(dppm)][PF6], which have shown to be extremely
air-sensitive. However in our case, the reactions of 1,
2, and 3 with organic thiols such as HSPh in MeOH in
the presence of NaBPh4 produced complex mixtures
from which no pure compound was isolated. In contrast
with this, the reaction with 2-mercaptopyridine (HSPy)
allowed the isolation of red-orange microcrystalline
materials. No bands attributable to ν(SH) or ν(RuH)
were observed in the IR spectrum of these compounds.
Instead, one medium band near 3200 cm-1, assigned to
(27) Bottomley, F.; Drummond, D. F.; Egharevba, G. O.; White, P.
S. Organometallics 1986, 5, 1620.
(28) de los R´ıos, I.; J ime´nez-Tenorio, M.; Padilla, J .; Puerta, M. C.;
Valerga, P. Organometallics 1996, 15, 4565, and references therein.
(29) de los R´ıos, I.; J ime´nez-Tenorio, M.; Puerta, M. C.; Valerga, P.
J . Am. Chem. Soc. 1997, 119, 6529.
(30) Conroy-Lewis, F. M.; Simpson, S. J . J . Chem. Soc., Chem.
Commun. 1991, 388. Treichel, P. M.; Schmidt, M. S.; Crane, R. A. Inorg.
Chem. 1991, 30, 379.

4398 Organometallics, Vol. 17, No. 20, 1998
Coto et al.
ν(NH), was present. This band is consistent with the
presence of one broad resonance in the range 10-12
1
ppm in their H NMR spectra, attributable to nitrogen-
bound protons, suggesting that HSPy exists as its 1H-
pyridine-2-thione tautomeric form SdCCHdCHCHd
CHNH in these complexes, which according to microanal-
ysis can hence be formulated as [CpRu(SdCCHdCHCHd
CHNH)(PEt3)2][BPh4] (8), [CpRu(SdCCHdCH-CHd
CHNH)(PPh3)(PMeiPr2)][BPh4] (9), and [Cp*Ru(Sd
CCHdCHCHdCHNH)(PEt3)2][BPh4] (10), respectively.
NMR spectral data suggest for these compounds a
typical three-legged piano stool structures, with the 1H-
pyridinethione ligand attached to the metal through the
sulfur atom, as shown:
F igu r e 2. ORTEP drawing (50% probability thermal
ellipsoids) of [Cp*Ru(S2COiPr)(PEt3)]. H atoms are omitted.
dithiocarbamate complexes, are too ambiguous to allow
unequivocal distiction between η1- and η2-coordination.
The 1H NMR spectra of all these compounds display one
single C5H5 or C5Me5 resonance, together with the
signals corresponding to the phosphine protons plus
those of the R group in the xanthate, or ethyl protons
in the dithiocarbamate. In all cases, one singlet is
observed in their 31P{1H} NMR spectra. Apart from
microanalysis, the distinction between η1- and η2-
coordination for the xanthate or dithiocarbamate ligands
can be made on the basis of the 13C{1H} NMR spectra.
All compounds containing a bidentate xanthate or
dithiocarbamate have lost one phosphine, and therefore
the resonances for the carbon atoms directly attached
to phosphorus appear as doublets. However, when the
coordination is η1, the corresponding complex contains
two phosphine ligands, and the resonances for the
phosphorus-bound carbon atoms appear as virtual
triplets. In xanthate complexes, the resonance of the
CS2 quaternary carbon, when observed, also allows
discrimination between η1- and η2-coordination, since
coupling with phosphorus is frequently observed; hence
one triplet indicates the presence of two phosphorus
atoms in the complex, as it occurs for compounds 13a -
c, whereas for complexes containing one phosphine
ligand the CS2 resonance appears as one doublet. For
dithiocarbamate complexes 14, 15, and 16 such reso-
nance has not been detected, possibly because of the
quadrupolar 14N nucleus.
The crystal structure of compound 12c was deter-
mined. An ORTEP view of the molecule is shown in
Figure 2. Selected bond lengths and angles are listed
in Table 3. The crystal contains discrete neutral
molecules with a pseudooctahedral three-legged piano
stool structure, in which three of the positions are
occupied by the C5Me5 ring, one by the phosphine
ligand, and the remaining two by the sulfur atoms of
the xanthate moiety. This arrangement is essentially
identical to that observed for the thioxanthate complex
[CpRu(S2CSPrn)(PPh3)].33 The S2CO unit of the xan-
thate is planar, with angles around C(11) consistent
with an sp2 hybridization. The Ru-S and C-S separa-
The tautomeric processes in 2-mercaptopyridine are
well established.31,32 In fact, the mercaptopyridine in
its free form exists predominantly as 1H-pyridinethione,
and coordinates as such through the sulfur atom, as in
our case. HSPy may also coordinate as the conjugate
anion pyridine-2-thiolate, PyS-, in various ways which
include S-monodentate, S,N-bidentate or even bridg-
ing.17,31,32 Attempts made to obtain neutral η1- or η2-
pyridinethiolate complexes by deprotonation of 8-10
were unsuccessful. However, we succeeded in preparing
a range of neutral derivatives containing alkylxanthates
or diethyldithiocarbamate as ligands, these acting as
η1- or η2-depending upon the particular complex. Thus,
the metathetical exchange reaction of 2 and 3 with
potassium alkylxanthates KS2COR (R ) Me, Et, iPr) in
refluxing EtOH afforded the neutral chelate complexes
i
[CpRu(η2-S2COR)(PMeiPr2)] (R ) Me 11a , Et 11b, Pr
11c) and [Cp*Ru(η2-S2COR)(PEt3)] (R ) Me 12a , Et
i
12b, Pr 12c), respectively. However, when the same
reactions were performed starting from 1, the isolated
products [CpRu(η1-S2COR)(PEt3)2] (R ) Me 13a , Et 13b,
iPr 13c) contained the xanthate bound as monodentate.
In analogous fashion, the reaction of 2 and 3 with
sodium diethyldithiocarbamate in acetone under reflux
yielded the corresponding chelate complexes [CpRu(η2-
S2CNEt2)(PMeiPr2)] (14) and [Cp*Ru(η2-S2CNEt2)(PEt3)]
(15), whereas from the reaction of 1, [CpRu(η1-S2-
CNEt2)(PEt3)2] (16) was obtained. The IR spectra of all
these derivatives show the characteristic bands associ-
ated with xanthate or dithiocarbamate ligands, although
the values found for ν(CS), as well as for ν(CN) in the
(31) Raper, E. Coord. Chem. Rev. 1985, 61, 115.
(32) Deeming, A. J .; Hardcastle, K. I.; Meah, M. N.; Bates, P. A.;
Dawes, H. M.; Hursthouse, M. B. J . Chem. Soc., Dalton Trans. 1988,
227. Baker, P. K.; Hughes, S. J . Coord. Chem. 1995, 35, 1.
(33) Shaver, A.; Plouffe, P.-Y.; Bird, P.; Livingstone, E. Inorg. Chem.
1990, 29, 1826.

Half-Sandwich Ruthenium Phosphine Complexes
Organometallics, Vol. 17, No. 20, 1998 4399
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [Cp *Ru (S2COiP r )(P Et3)] (12c) w ith
Estim a ted Sta n d a r d Devia tion s in P a r en th eses.
favored process, but in our system it involves the
elimination of one phosphine ligand. Thus, the forma-
tion of the chelate ring must compensate the loss of a
metal-phosphorus bond. This happens with relative
ease if one of the phosphine ligands is labile, e.g., PPh3
in complex 2 or PEt3 in 3. The fact that PEt3 is labile
in 3 but not in 1 is possibly due to the stronger electron-
releasing properties of the C5Me5 ligand compared to
C5H5, which may help in the stabilization of 16-electron
species formed upon phosphine dissociation36 prior to
chelate ring closure. Subsequent attack of the released
phosphine to the ROCS2 carbon atom of the xanthate
ligand has not been observed. Such a process leads to
zwitterionic species of the type S2C-(P+R3)OR, and this
has been reported to occur in some instances.37
Ru(1)-S(1)
Ru(1)-S(1)
Ru(1)-P(1)
Ru(1)-C(1)
Ru(1)-C(2)
Ru(1)-C(3)
2.393(2)
2.406(2)
2.301(2)
2.198(5)
2.192(5)
2.197(5)
Ru(1)-C(4)
Ru(1)-C(5)
S(1)-C(11)
S(2)-C(11)
O(1)-C(11)
O(1)-C(12)
2.194(5)
2.181(5)
1.682(5)
1.678(5)
1.315(6)
1.475(7)
S(1)-Ru(1)-S(2)
S(1)-Ru(1)-P(1)
S(2)-Ru(1)-P(1)
Ru(1)-S(1)-C(11)
Ru(1)-S(2)-C(11)
71.45(6)
90.84(8)
92.52(7)
87.9(2)
C(11)-O(1)-C(12)
S(1)-C(11)-S(2)
S(1)-C(11)-O(1)
S(2)-C(11)-O(1)
119.6(4)
113.0(3)
126.9(4)
120.1(4)
87.6(2)
tions are very similar, suggesting an essentially sym-
metrical chelating mode for the xanthate, and consistent
with values found in the literature for other ruthenium
xanthate34 and thioxanthate33 complexes. All the other
distances and angles in the C5Me5 and phosphine ligand
are in the normal range and do not require further
comments.
It is interesting that in the series of xanthate and
dithiocarbamate complexes described in this work, the
η1-coordination has only been observed in cyclopenta-
dienylbis(triethylphosphine) derivatives. Clearly, com-
plexes containing monodentate xanthate or dithiocar-
bamate must be intermediates in the formation of the
corresponding chelate species, as has been proposed for
the reaction of [RuCl2(L)3] (L ) PPh3, PEtPh2, P(OMe)-
Ph2, P(OEt)Ph2) and [RuCl2(L)4] (L ) PPh(OMe)2, PMe2-
Ph, PMePh2) with alkali metal salts of several dithio
acids such as xanthates and dithiocarbamates (S-S),
to give [Ru{η2-(S-S)}2(L)2] derivatives.35 The chelate
ring closure reaction is an entropy-driven, thermally
Ack n ow led gm en t. We wish to thank Dr. Purifica-
cion Herna´ndez and Dr. Dolores Bellido, from the
Departamento de Qu´ımica Anal´ıtica, Universidad de
Ca´diz, for UV-vis spectral measurements. Financial
support from the Ministerio de Educacio´n y Ciencia of
Spain (DGICYT, Project PB94-1306) and J unta de
Andaluc´ıa (PAI-FQM 0188) is gratefully acknowledged.
Su p p or tin g In for m a tion Ava ila ble: ORTEP drawings
and tables giving fractional atomic coordinates, thermal
parameters, and bond distances and angles for 7 and 12c (12
pages). Ordering information is given on any current mast-
head page.
OM980340H
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