Substitution reactions of [Ru(dppe)(CO)(H2O)3][OTf]2

Article abstract of DOI:10.1021/ic020029z

The labile nature of the coordinated water ligands in the organometallic aqua complex [Ru(dppe)(CO)(H₂O)₃][OTf]₂ (1) (dppe = Ph₂PCH₂CH₂PPh₂; OTf = OSO₂CF₃) has been investigated through substitution reactions with a range of incoming ligands. Dissolution of 1 in acetonitrile or dimethyl sulfoxide results in the facile displacement of all three waters to give [Ru(dppe)(CO)(CH₃CN)₃][OTf]₂ (2) and [Ru(dppe)(CO)(DMSO)₃][OTf]₂ (3), respectively. Similarly, 1 reacts with Me₃CNC to afford [Ru(dppe)(CO)(CNCMe₃)₃][OTf]₂ (4). Addition of 1 equiv of 2,2′-bipyridyl (bpy) or 4,4′-dimethyl-2,2′-bipyridyl (Me₂bpy) to acetone/water solutions of 1 initially yields [Ru(dppe)(CO)(H₂O)(bpy)][OTf]₂ (5a) and [Ru(dppe)(CO)(H₂O)(Me₂bpy)][OTf]₂ (6a), in which the coordinated water lies trans to CO. Compounds 5a and 6a rapidly rearrange to isomeric species (5b, 6b) in which the ligated water is trans to dppe. Further reactivity has been demonstrated for 6b, which, upon dissolution in CDCl₃, loses water and coordinates a triflate anion to afford [Ru(dppe)(CO)(OTf)(Me₂bpy)][OTf] (7). Reaction of 1 with CH₃CH₂CH₂SH gives the dinuclear bridging thiolate complex [{(dppe)Ru(CO)}₂(μ-SCH₂ CH₂CH₃)₃][OTf] (8). The reaction of 1 with CO in acetone/ water is slow and yields the cationic hydride complex [Ru(dppe)(CO)₃H][OTf] (9) via a water gas shift reaction. Moreover, the same mechanism can also be used to account for the previously reported synthesis of 1 upon reaction of Ru(dppe)(CO)₂(OTf)₂ with water (Organometallics 1999, 18, 4068).

Full text of DOI:10.1021/ic020029z

Inorg. Chem. 2002, 41, 3137−3145
Substitution Reactions of [Ru(dppe)(CO)(H O)3][OTf]2
2
Matthew D. Hargreaves, Mary F. Mahon, and Michael K. Whittlesey*
Department of Chemistry, UniVersity of Bath, ClaVerton Down, Bath BA2 7AY, U.K.
Received January 9, 2002
The labile nature of the coordinated water ligands in the organometallic aqua complex [Ru(dppe)(CO)(H O)3][OTf]2
2
(1) (dppe ) Ph2PCH CH PPh2; OTf ) OSO CF ) has been investigated through substitution reactions with a
2
2
2
3
range of incoming ligands. Dissolution of 1 in acetonitrile or dimethyl sulfoxide results in the facile displacement of
all three waters to give [Ru(dppe)(CO)(CH CN)3][OTf]2 (2) and [Ru(dppe)(CO)(DMSO)3][OTf]2 (3), respectively.
3
Similarly, 1 reacts with Me3CNC to afford [Ru(dppe)(CO)(CNCMe3)3][OTf]2 (4). Addition of 1 equiv of 2,2′-bipyridyl
(bpy) or 4,4′-dimethyl-2,2′-bipyridyl (Me2bpy) to acetone/water solutions of 1 initially yields [Ru(dppe)(CO)(H O)-
2
(bpy)][OTf]2 (5a) and [Ru(dppe)(CO)(H O)(Me2bpy)][OTf]2 (6a), in which the coordinated water lies trans to CO.
2
Compounds 5a and 6a rapidly rearrange to isomeric species (5b, 6b) in which the ligated water is trans to dppe.
Further reactivity has been demonstrated for 6b, which, upon dissolution in CDCl3, loses water and coordinates a
triflate anion to afford [Ru(dppe)(CO)(OTf)(Me2bpy)][OTf] (7). Reaction of 1 with CH CH CH SH gives the dinuclear
3
2
2
bridging thiolate complex [{(dppe)Ru(CO)}2(µ-SCH CH CH ) ][OTf] (8). The reaction of 1 with CO in acetone/
2
2
3 3
water is slow and yields the cationic hydride complex [Ru(dppe)(CO)3H][OTf] (9) via a water gas shift reaction.
Moreover, the same mechanism can also be used to account for the previously reported synthesis of 1 upon
reaction of Ru(dppe)(CO)2(OTf)2 with water (Organometallics 1999, 18, 4068).
Introduction
applications of water-soluble complexes in organic synthesis,2
biphasic and homogeneous catalysis,3 and medicinal chem-
istry.4 Of all of the late transition metals, aqua complexes
of ruthenium(II) have attracted the most attention since the
Water is ubiquitous as a ligand in coordination chemistry.
In contrast, organometallic aqua complexes are far less
common largely because the presence of both soft ligands
such as phosphines and CO and harder oxygen donors such
as water is thought of as being incompatible. In recent years,
however, considerable interest has developed into the study
of aqueous organometallic chemistry1 due to the potential
(2) (a) Laurenczy, G.; Merbach, A. E. J. Chem. Soc., Chem. Commun.
1993, 187. (b) Le, T. X.; Merola, J. S. Organometallics 1993, 12,
3798. (c) Aebischer, N.; Frey, U.; Merbach, A. E. Chem. Commun.
1998, 2303. (d) Balzarek, C.; Tyler, D. R. Angew. Chem., Int. Ed.
1999, 38, 2406. (e) Takahashi, Y.; Kikichi, S.; Akita, M.; Moro-oka,
Y. Chem. Commun. 1999, 1491. (f) Balzarek, C.; Weakley, T. J. R.;
Tyler, D. R. J. Am. Chem. Soc. 2000, 122, 9427. (g) Breno, K. L.;
Tyler, D. R. Organometallics 2001, 20, 3864.
(3) (a) McGrath, D. V.; Grubbs, R. H.; Ziller, J. W. J. Am. Chem. Soc.
1991, 113, 3611. (b) Hillmyer, M. A.; Lepetit, C.; McGrath, D. V.;
Novak, B. M.; Grubbs, R. H. Macromolecules 1992, 25, 3345. (c)
Wang, L.; Lu, R. S.; Bau, R.; Flood, T. C. J. Am. Chem. Soc. 1993,
115, 6999. (d) Ogo, S.; Makihara, N.; Watanabe, Y. Organometallics
1999, 18, 5470. (e) Verspui, G.; Schanssema, F.; Sheldon, R. A.
Angew. Chem., Int. Ed. 2000, 39, 804. (f) Makihara, N.; Ogo, S.;
Watanabe, Y. Organometallics 2001, 20, 497. (g) Ogo, S.; Makihara,
N.; Kaneko, Y.; Watanabe, Y. Organometallics 2001, 20, 4903.
(4) (a) Alberto, R.; Egli, A.; Abram, U.; Hegetschweiler, K.; Gramlich,
V.; Schubiger, P. A. J. Chem. Soc., Dalton Trans. 1994, 2815. (b)
Egli, A.; Hegetschweiler, K.; Alberto, R.; Abram, U.; Schibli, R.;
Hedinger, R.; Gramlich, V.; Kissner, R.; Schubiger, P. A. Organo-
metallics 1997, 17, 1833. (c) Alberto, R.; Schibli, R.; Egli, A.;
Schubiger, A. P.; Abram, U.; Kaden, T. A. J. Am. Chem. Soc. 1998,
120, 7987. (d) Fish, R. H. Coord. Chem. ReV. 1999, 185/186, 569.
(e) Aebischer, N.; Schibli, R.; Alberto, R.; Merbach, A. E. Angew.
Chem., Int. Ed. 2000, 39, 254.
* Corresponding author. E-mail: chsmkw@bath.ac.uk.
(1) (a) Cornils, B.; Herrmann, W. A. Aqueous Phase Organometallic
Catalysis; Wiley-VCH: Weinheim, 1998. (b) Joo´, F.; Katho´, A. J.
Mol. Catal. 1997, 116, 3. (c) Richens, D. T. The Chemistry of Aqua
Ions; Wiley: Chichester, 1997. (d) Roundhill, D. M. AdV. Organomet.
Chem. 1995, 38, 155. (e) Ko¨lle, U.; Go¨rissen, R.; Wagner, T. Chem.
Ber. 1995, 128, 911. (f) Eisen, M. S.; Haskel, A.; Chen, H.; Olmstead,
M. M.; Smith, D. P.; Maestre, M. F.; Fish, R. H. Organometallics
1995, 14, 2806. (g) Svetlanova-Larsen, A.; Zoch, C. R.; Hubbard, J.
L. Organometallics 1996, 15, 3076. (h) Caraiati, E.; Lucenti, E.;
Pizzotti, M.; Roberto, D.; Ugo, R. Organometallics 1996, 15, 4122.
(i) Takahashi, Y.; Akita, M.; Hikichi, S.; Moro-oka, Y. Inorg. Chem.
1998, 37, 3186. (j) Leung, W.-H.; Chan, E. Y. Y.; Wong, W.-T. Inorg.
Chem. 1999, 38, 136. (k) Balzarek, C.; Weakley, T. J. R.; Kuo, L. Y.;
Tyler, D. R. Organometallics 2000, 19, 2927. (l) Akita, M.; Takahashi,
Y.; Hikichi, S.; Moro-oka, Y. Inorg. Chem. 2001, 40, 169. (m) Hughes,
R. P.; Lindner, D. C.; Smith, J. M.; Zhang, D.; Incarvito, C. D.; Lam,
K.-C.; Liable-Sands, L. M.; Sommer, R. D.; Rheingold, A. L. J. Chem.
Soc., Dalton Trans. 2001, 2270. (n) Poth, T.; Paulus, H.; Elias, H.;
Du¨cker-Benfer, C.; van Eldik, R. Eur. J. Inorg. Chem. 2001, 1361.
10.1021/ic020029z CCC: $22.00 © 2002 American Chemical Society
Published on Web 05/16/2002
Inorganic Chemistry, Vol. 41, No. 12, 2002 3137

Hargreaves et al.
triflate (Lancaster) was handled in a nitrogen-filled glovebox. 2,2′-
Bipyridyl (bpy) and 4,4′-dimethyl-2,2′-bipyridyl (Me2bpy) (Ald-
rich), propanethiol (Aldrich), CO (BOC, 99.9%), and 13CO (Pro-
mochem, 99%) were used as received. Ru(dppe)(CO)2(OTf)2 and
+2 oxidation state of this metal has been shown to exhibit
a strong binding affinity for both water and π acid ligands
such as alkenes.5
The presence of “organometallic” ligands can have
remarkable effects on the substitution patterns of aqua
complexes. Kinetic measurements using 17O NMR spectros-
copy have revealed that the relative rates of water ex-
change in [(η6-C6H6)Ru(H2O)3]2+, [Ru(H2O)5(CO)]2+, and
[Ru(H2O)6]2+ are in the ratio 640:2.5:1. Merbach and co-
workers have reported extensive studies on the rates of water
exchange and displacement in [Ru(H2O)5L]2+, [Ru(H2O)4L2]2+
(L ) C2H4, CO, CH3CN, N2), and [(arene)Ru(H2O)3]2+.6
Thus, the cationic species [Ru(H2O)5L]2+ shows different
rates of exchange for water ligands in the equatorial and axial
positions and attempts have been made to correlate this
reactivity to the labilizing cis and trans effects of both the
ancilliary ligands, L, and water itself. While trans effects
are comparatively well understood for square planar com-
plexes, much less is known about similar effects in octahedral
complexes,7 largely because there are a greater number of
variables to consider in the latter including the metal center,
nature of the leaving groups, and mechanisms of reaction
(Id, Ia, etc.).
Ru(dppe)(CO)3 were prepared as described in the literature.8,9 1
H
NMR spectra were recorded on Bruker AVANCE 300 or Varian
Mercury 400 MHz NMR spectrometers and referenced to residual
protio solvent resonances (acetone δ 2.05, chloroform δ 7.27,
dimethyl sulfoxide (DMSO) δ 2.54). All spectra were recorded in
mixtures of acetone-d6 and H2O unless otherwise stated. 31P{1H}
and 19F NMR chemical shifts were referenced externally to 85%
H3PO4 and CFCl3, respectively (both at δ 0.00). 13C{1H} NMR
1
1
spectra were referenced to acetone-d6 at δ 30.6. H COSY, H-
13C HMQC, and HMBC experiments were performed on the
AVANCE spectrometer using standard Bruker pulse sequences.
Only the most pertinent NMR data are reported with peak positions
given in parts per million and coupling constants in hertz. IR spectra
reported in cm-1 were recorded on a Nicolet Prote´ge´ 460 FTIR
spectrometer. Elemental analyses were performed at the University
of Bath.
[Ru(dppe)(CO)(H2O)3][OTf]2 (1). To a solution of Ru(dppe)-
(CO)2(OTf)2 (70 mg, 0.082 mmol) in CH2Cl2 (5 mL) was added
10 equiv of water (15 µL, 0.83 mmol). Pale Yellow crystals of 1
slowly crystallized from the solution after 2 days at 5 °C (59.5
1
mg, yield 85%). H NMR (293 K): 7.98-7.90 (6H, m, PC6H5),
7.55-7.50 (10H, m, PC6H5), 7.37 (2H, m, PC6H5), 6.94 (2H, m,
PC6H5), 3.49-3.43 (2H, m, PCH2), 3.14-3.08 (2H, m, PCH2). 31P-
{1H}: 66.5 (s). 19F: -79.20 (s). 13C{1H}: 198.3 (t, JCP ) 17.9,
CO). Larger quantities of 1 were more easily prepared by addition
of AgOTf (272 mg, 1.06 mmol) to a solution of all cis-Ru(dppe)-
(CO)2Cl2 (302 mg, 0.48 mmol) in 15 mL of CH2Cl2 followed
immediately by water (86 µL, 4.77 mmol). After the mixture was
stirred for 90 min with the total exclusion of light, the precipitate
of AgCl was removed by filtration and the pale yellow filtrate
concentrated by half. Crystals of 1 slowly precipitated out of
solution (130 mg, yield 43%).
We have recently reported the formation of the carbonyl
aqua complex [Ru(dppe)(CO)(H2O)3]2+ (1) upon addition of
water to [Ru(dppe)(CO)2(OTf)2].8 The X-ray structure de-
termination of 1 shows that the molecule contains a fac-
[Ru(OH2)3]2+ moiety, thus affording the possibility of
studying the lability of the coordinated waters (two trans to
P, one trans to CO) with a range of incoming ligands L.
Prior to embarking on kinetic studies on the reactivity of 1,
we have sought to establish the substitution chemistry of 1
with a range of unidentate, bidentate, and potentially bridging
groups. We now report that both mononuclear and binuclear
ruthenium(II) complexes can be formed upon substitution
of one, two, or all three water ligands. In many of these
reactions, the products have been characterized by X-ray
crystallography, which has provided evidence for hydrogen
bonding interactions in the solid state.
[Ru(dppe)(CO)(CH3CN)3][OTf]2 (2). A sample of 1 (10 mg,
0.011 mmol) was placed in a J. Young’s resealable NMR tube and
dissolved in CD3CN (0.6 mL). The 31P{1H} NMR spectrum showed
immediate conversion to 2. Removal of the solvent and recrystal-
lization of the residue from chloroform/acetonitrile Et2O gave 2 in
analytically pure form. 1H NMR (acetone-d6, 293 K): 2.78 (s, 6H,
CH3CN), 2.00 (s, 3H, CH3CN). 31P{1H}(CD3CN): 62.3 (s).
19F(CD3CN): -79.20 (s). 13C{1H}(CD3CN): 194.1 (t, JCP ) 16.1,
CO), 3.5 (s, CH3CN), 2.2 (s, CH3CN). IR (Nujol): 2324 m (νCN),
2294 m (νCN), 2020 vs (νCO).
[Ru(dppe)(CO)(Me2SO)3][OTf]2 (3). A sample of 1 (10 mg,
0.011 mmol) was placed in a J. Young’s resealable NMR tube and
dissolved in degassed DMSO (0.6 mL). The 31P{1H} NMR
spectrum showed immediate conversion to 3. Removal of the
solvent and recrystallization of the residue from acetone/DMSO/
Et2O gave 3 in analytically pure form (8 mg, 75% yield). 1H NMR
(DMSO-d6, 293 K): 3.34 (s, 12H, Me2SO), 2.99 (s, 6H, Me2SO).
31P{1H}: 64.7 (s). 19F: -79.33 (s). 13C{1H}: 199.1 (t, JCP ) 17.4,
CO). IR (KBr): 1973 vs (νCO).
Experimental Section
General Comments. All reactions were carried out using
standard Schlenk and high vacuum techniques. Water was doubly
distilled and degassed prior to use, while CH2Cl2 was distilled from
P2O5. Deuterated solvents (Goss) were dried over CaH2 (CDCl3
and CD2C12); (CD3)2CO and CD3CN were freeze-pump-thaw
degassed while D2O was degassed by bubbling with argon. Silver
(5) (a) Ko¨lle, U. Coord. Chem. ReV. 1994, 135/136, 623. (b) For a very
recent overview of aqueous ruthenium chemistry, see: Grundler, P.
V.; Laurenczy, G.; Merbach, A. E. HelV. Chim. Acta 2001, 84, 2854.
(6) (a) Dadci, L.; Elias, H.; Frey, U.; Ho¨rnig, A.; Ko¨lle, U.; Merbach, A.
E.; Paulus, H.; Schneider J. S. Inorg. Chem. 1995, 34, 306. (b)
Aebischer, N.; Sidorenkova, E.; Ravera, M.; Laurenczy, G.; Osella,
D.; Weber, J.; Merbach, A. E. Inorg. Chem. 1997, 36, 6009. (c)
Aebischer, N.; Churlaud, R.; Dolci, L.; Frey, U.; Merbach, A. E. Inorg.
Chem. 1998, 37, 5915. (d) Cayemittes, S.; Poth, T.; Fernandez, M. J.;
Lye, P. G.; Becker, M.; Elias, H.; Merbach, A. E. Inorg. Chem. 1999,
38, 4309. (e) Meier, U. C.; Scopelliti, R.; Solari, E.; Merbach, A. E.
Inorg. Chem. 2000, 39, 3816.
[Ru(dppe)(CO)(CNCMe3)3][OTf]2 (4). Addition of 81 µL of
Me3CNC (0. 72 mmol) to an acetone-d6/H2O solution of 1 (126
mg, 0.14 mmol) gave an immediate color change from pale yellow
to colorless with the appearance of a new resonance in the 31P-
{1H} NMR spectrum at δ 54.8. This species fully converted to a
(7) Coe, B. J.; Glenwright, S. J. Coord. Chem. ReV. 2000, 203, 5.
(8) Mahon, M. F.; Whittlesey, M. K.; Wood, P. T. Organometallics 1999,
18, 4068.
(9) Bunten, K. A.; Farrar, D. H.; Poe¨, A. J.; Lough, A. J. Organometallics
2000, 19, 3674.
3138 Inorganic Chemistry, Vol. 41, No. 12, 2002

Reactions of [Ru(dppe)(CO)(H2O)3][OTf]2
Table 1. Experimental Data for the X-ray Diffraction Studies of Compounds 2, 3, 4, 7, and 8
2
3
4
7
8
empirical formula
formula weight
temp/K
C37H35Cl6F6N3O7P2RuS2 C38H48F6O11P2RuS5
C45.50H54F6N3O7.50P2RuS2 C41H36F6N2O7P2RuS2 C67H75F3O6P4Ru2S4
1187.51
1118.07
1104.05
1009.85
1490.55
170(2)
150(2)
150(2)
170(2)
170(2)
crystal system
space group
a/Å
b/Å
c/Å
monoclinic
P21/n
12.2606(3)
13.8259(3)
29.5038(5)
orthorhombic
P212121
11.5396(1)
20.2593(1)
20.4265(1)
monoclinic
P21/n
12.1103(1)
21.9721(1)
19.6937(2)
monoclinic
P21/c
14.2643(2)
13.7762(2)
22.1901(4)
triclinic
P1h
12.655(1)
12.998(1)
21.065(2)
100.982(5)
92.936(5)
103.143(5)
3296.11(5)
2
R/deg
â/deg
99.587(1)
90.1040(3)
108.196(1)
γ/deg
U/Å3
4931.45(18)
4
4775.39(5)
4
5240.26(7)
4
4143.5(1)
4
Z
crystal size/mm
θ range for data
collection/deg
index ranges
0.37 × 0.20 × 0.13
0.28 × 0.25 × 0.25
0.30 × 0.20 × 0.10
0.17 × 0.13 × 0.13
0.25 × 0.20 × 0.10
1.71-26.37
4.60-30.03
3.53-27.12
3.58-27.48
3.54-27.50
-15 e h e 15;
-16 e k e 17;
-32 e l e 34
20 389
-15 e h e 16;
-28 e k e 27;
-28 e l e 28
92 137
-15 e h e 13;
-27 e k e 28;
-25 e l e 25
82 263
0 e h e 18;
-17 e k e 17;
-28 e l e 27
56 381
0 e h e 16;
-16 e k e 16;
-27 e l e 27
37 510
reflns collected
independent reflns
data/restraints/params
final R1, wR2 [I > 2σ(I)] 0.0383, 0.1042
final R1, wR2 (all data) 0.0541, 0.1191
9 648 [R(int) ) 0.0329] 13 879 [R(int) ) 0.0377] 11 508 [R(int) ) 0.0566] 94 67 [R(int) ) 0.0468] 14 940 [R(int) ) 0.0297]
9 648/15/609
13 879/0/596
0.0337, 0.0749
0.0350, 0.0743
11 508/3/635
0.0504, 0.1254
0.0580, 0.1312
94 67/0/551
14 940/0/776
0.0308, 0.0758
0.0345, 0.0786
0.0332, 0.0934
0.0428, 0.1006
second product at δ 52.4 over 48 h. Layering with Et2O gave white
analytically pure crystals of 4 (83 mg, 66% yield). 1H NMR
(acetone-d6, 293 K): 1.79 (s, 9H, Me3CNC), 1.05 (s, 18H,
Me3CNC). 31P{1H}: 52.4 (s). 19F: -79.35 (s). 13C{1H}: 190.8 (t,
JCP ) 12.0, CO), 62.2 (s, CNCMe3), 61.6 (s, CNCMe3), 30.0 (s,
CNCMe3), 29.2 (s, CNCMe3). IR (KBr): 2233 s (νCN), 2212 s (νCN),
2071 vs (νCO).
crystals formed overnight (40 mg, 32% yield). 1H NMR (acetone-
d6, 293 K): 7.81 (8H, t, JHH ) 8.39), 7.70 (8H, t, JHH ) 8.39),
7.49-7.32 (24H, m), 2.65-2.85 (8H, br, PCH2 + SCH2), 1.29 (4H,
m, CH2CH3), 1.17 (2H, m, SCH2), 0.86 (6H, t, JHH ) 7.20, CH3),
0.31 (2H, m, CH2CH3), -0.23 (3H, t, JHH ) 7.20, CH3). 31P{1H}:
47.0 (s). 13C{1H}: 201.4 (t, JCP ) 9.6, CO). IR (KBr): 1953 vs
(νCO).
Reaction of 1 with 2,2′-Bipyridyl. A sample of 1 (25 mg, 0.029
mmol) was dissolved in acetone-d6/H2O, and 1 equiv of 2,2′-
bipyridyl (5 mg, 0.032 mmol) was added. A new species, 5a, formed
[Ru(dppe)(CO)3H][OTf] (9). One equivalent of HOTf (3.5 µL,
0.039 mmol) was added to a CO-saturated C6D6 solution of
Ru(dppe)(CO)3 (23 mg, 0.039 mmol) at -78 °C. The solution was
thawed to room temperature with the appearance of a new singlet
for 9 at δ 64.6 in the 31P{1H} NMR spectrum. Over 1 week at
room temperature, small yellow crystals appeared, one of which
1
almost immediately as shown by 31P{1H} NMR spectroscopy. H
NMR (273 K): 8.89 (2H, d, JHH ) 8.05), 8.53 (2H, d, JHH ) 8.05),
8.42 (2H, d, JHH ) 8.05), 8.07 (2H, dd, JHH ) 8.05). 31P{1H}: 58.3
(s). IR (KBr): 1996 vs (νCO). Conversion to the isomeric product
5b was observed upon warming to room temperature for 1 h.
31P{1H} NMR (293 K): 64.7 (d, JPP ) 13.1), 52.2 (d, JPP ) 13.1).
IR (KBr): 2000 vs (νCO).
1
was used for the structure determination. H NMR (benzene-d6,
293 K): -7.57 (1H, t, JHP ) 17.80). 31P{1H}: 64.6 (s). 13C{1H}:
192.2 (dd, JCP ) 76.3, 17.4, CO), 190.0 (t, JCP ) 7.9, CO). IR
(Nujol): 2110 vs (νCO), 2062 vs (νCO), 2051 vs (νCO).
Reaction of 1 with 4,4′-Dimethyl-2,2′-bipyridyl. The reaction
X-ray Experimental Data. Crystallographic data for compounds
2, 3, 4, 7, and 8 are summarized in Table 1. X-ray data were
collected on a Nonius KappaCCD diffractometer throughout. Full
matrix anisotropic refinement (SHELXL-97)10 was implemented
in the final least-squares cycles for all structures. All data were
corrected for Lorentz, polarization and extinction. An absorption
correction (multiscan) was applied to the data for 2 and 4 (maximum
and minimum transmission factors were 1.027, 0.989 and 1.055,
0.944, respectively). Hydrogens were included at calculated posi-
tions throughout. The asymmetric unit of 2 contains two molecules
of chloroform in addition to one molecule of the ruthenium salt
complex. One of these solvent molecules exhibited positional
disorder of the chlorine atoms in the ratio 4:1. In 3, the phenyl
group based on C2 was found to be disordered in the ratio 56:44.
The ADPs pertaining to the R-carbon of each disordered portion
were constrained to be similar in the final least-squares assignment.
The motif in the structure of 3 also contains a molecule of acetone.
The asymmetric unit in 4 contains a molecule of acetone with
half-site occupancy. Triflate based on S2 exhibits some positional
of 1 with Me2bpy was carried out in a manner similar to that above,
1
to give 6a almost immediately. H NMR (258 K): 2.55 (s, Me).
31P{1H}: 58.6 (s). 19F: -79.35 (s). 13C{1H}: 199.5 (t, JCP ) 15.6,
CO), 29.2 (s, CH3). Upon warming to room temperature for 1 h,
conversion to the isomeric product 6b was observed. 1H NMR (293
K): 2.61 (s, CH3), 2.30 (s, CH3). 31P{1H}: 64.7 (d, JPP ) 13.1),
52.1 (d, JPP ) 13.1). 13C{1H}: 199.4 (t, JCP ) 16.1, CO), 21.2 (s,
Me), 20.7 (s, Me). IR (KBr): 2004 vs (νCO).
[Ru(dppe)(CO)(OTf)(Me2bpy)][OTf] (7). A sample of 1 (62
mg, 0.070 mmol) was dissolved in acetone/H2O and 1 equiv of
Me2bpy (13 mg, 0.070 mmol) was added. After 1 day at room
temperature, the solution was pumped to dryness and the residue
redissolved in CDCl3. Yellow crystals of 7 were slowly precipitated
1
from the solution (48 mg, 68% yield). H NMR (CDCl3, 293 K):
2.61 (s, CH3), 2.30 (s, CH3). 31P{1H} (CD2Cl2): 67.3 (d, JPP
)
14.3), 51.8 (d, JPP ) 14.3). 19F (CD2Cl2): -78.97 (s), -79.07 (s).
IR (KBr): 2005 vs (νCO).
[{Ru(dppe)(CO)}2(µ-SCH2CH2CH3)3][OTf] (8). 1-Propanethiol
(38 µL, 0.42 mmol) was added to an acetone/H2O solution of 1
(125 mg, 0.14 mmol) at room temperature to give a deep red
solution. This was pumped to dryness and the residue was
redissolved in acetone and layered with diethyl ether. Yellow/orange
(10) Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, A46, 467-473.
Sheldrick, G. M. SHELXL-97, a computer program for crystal
structure refinement; University of Go¨ttingen: Go¨ttingen, Germany,
1997.
Inorganic Chemistry, Vol. 41, No. 12, 2002 3139

Hargreaves et al.
disorder approximately along the S(2)-C(44) vector which could
not be successfully modeled. C-F distances were restrained to be
similar in this anion. The gross structure was heavily dominated
by C-H‚‚‚O interactions. Disorder within the second triflate in this
compound may be a consequence of the partial occupancy of the
solvent, which is implicit in the C-H‚‚‚O network. There is one
full molecule of recrystallization (acetone) within the asymmetric
unit of 8. The highest residual electron density in this structure is
in the region of C61 in the difference Fourier map, which is possibly
indicative of some slight disorder within the propyl group attached
to S(1).
The structure of 9 is, in many ways, a testimony to the
capabilities of modern diffractometers with area detectors. Despite
copious efforts, it proved impossible to grow crystals of optimum
size for a structure determination in this case. Thus, data were
collected on a very small crystal (0.075 × 0.075 × 0.1 mm) over
a 3 day period. Structural solution proceeded readily, despite the
abysmal R(int) and the rapid falloff in diffraction from this very
small sample. The final convergence (R1 ) 15.12) was hampered
by disorder (approximately 60:40) of the anion, and the presence
of a fragment of solvent. Metric data for the anion are poor
(a consequence of the sample size), and this region of the electron
density map was treated isotropically in the latter stages of
refinement. The solvent was refined as a partial water molecule.
We make no other claim from this structure determination other
than the fact that it confirms the nature of the cation present.
In our discussions, we have highlighted and illustrated those
C-H‚‚‚O interactions which conform to the criteria proposed by
Desiraju.11 As methyl hydrogens were uniformly included at
calculated positions, it is worth remarking that there is extensive
evidence for further interactions in all structures, based on distances
between carbon atoms and triflate oxygens. Crystallographic data
for the structural analyses have been deposited with the Cambridge
Crystallographic Data Center, CCDC no. 176745 for compound 2,
no. 176746 for compound 3, no. 176747 for compound 4, no.
176748 for compound 7, and no. 176749 for compound 8.
Figure 1. ORTEX diagram of [Ru(dppe)(CO)(CH3CN)3][OTf]2‚2(CHCl3)
(2). Thermal ellipsoids are shown at the 30% level.
Table 2. Selected Bond Lengths [Å] and Angles [deg] for
[Ru(dppe)(CO)(CH3CN)3][OTf]2‚2(CHCl3) (2)
Ru(1)-C(33)
Ru(1)-N(1)
Ru(1)-P(1)
1.870(3)
2.109(3)
2.3092(8)
Ru(1)-N(2)
Ru(1)-N(3)
Ru(1)-P(2)
2.095(2)
2.115(3)
2.3126(8)
C(33)-Ru(1)-N(2)
N(2)-Ru(1)-N(1)
N(2)-Ru(1)-N(3)
C(33)-Ru(1)-P(1)
N(1)Ru-(1)-P(1)
C(33)-Ru(1)-P(2)
N(1)-Ru(1)-P(2)
P(1)-Ru(1)-P(2)
176.20(11)
83.13(9)
88.12(9)
91.04(9)
93.06(7)
86.12(9)
177.54(7)
84.49(3)
C(33)-Ru(1)-N(1)
C(33)-Ru(1)-N(3)
N(1)-Ru(1)-N(3)
N(2)-Ru(1)-P(1)
N(3)-Ru(1)-P(1)
N(2)-Ru(1)-P(2)
N(3)-Ru(1)-P(2)
93.59(11)
89.95(11)
89.74(10)
91.06(7)
176.96(7)
97.24(7)
92.71(7)
of 2 was provided by the appearance of two acetonitrile
methyl resonances in both the 1H and 13C{1H} NMR spectra
(eq 1). The IR spectrum of 2 exhibits two νCN stretches12 at
Results and Discussion
Attempts to find an appropriate solvent in which to study
the reactions of [Ru(dppe)(CO)(H2O)3][OTf]2, 1, initially
caused some problems. We previously noted that this
complex was not stable in chlorinated solvents. Similarly, 1
does not remain intact in acetone, where it forms a number
of products, believed to be mixed acetone-water adducts.
However, addition of 10 equiv of water to this mixture of
species in acetone solution regenerates 1 in essentially
quantitative yield. Hence, unless stated, the reactions below
were performed in acetone/water mixtures.
Reaction of [Ru(dppe)(CO)(H2O)3][OTf]2 with Mon-
dentate Ligands (L ) CH3CN, DMSO, Me3CNC). Dis-
solution of 1 in the coordinating solvents CH3CN and DMSO
leads to facile substitution of all three coordinated water
ligands and formation of [Ru(dppe)(CO)(CH3CN)3][OTf]2
(2) and [Ru(dppe)(CO)(DMSO)3][OTf]2 (3), respectively,
which have been characterized by NMR spectroscopy,
elemental analysis, and X-ray crystallography. The 31P{1H}
NMR spectra of 2 and 3 show only singlet resonances in
accord with a fac arrangement of coordinating solvent
molecules as in 1. Additional confirmation of the structure
2324 and 2294 cm-1, while the carbonyl band appears 30
cm-1 higher than that in 1, reflecting the poorer donor ability
of the acetonitrile relative to the water.
An ORTEX13 plot representing the asymmetric unit in the
X-ray structure of 2 (Figure 1) demonstrates the expected
octahedral coordination geometry about the ruthenium center.
Selected bond distances and angles are given in Table 2.
All three Ru-N distances are similar, although the average
value (2.106(3) Å) is considerably longer than average Ru-N
(12) (a) Thorburn, I. S.; Rettig, S. J.; James, B. R. J. Organomet. Chem.
1985, 296, 103. (b) Bianchini, C.; Dal Santo, V.; Meli, A.; Oberhauser,
W.; Psaro, R.; Vizza, F. Organometallics 2000, 19, 2433.
(13) McArdle, P. J. Appl. Crystallogr. 1994, 27, 438.
(11) Desiraju, G. R. Acc. Chem. Res. 1996, 29, 441.
3140 Inorganic Chemistry, Vol. 41, No. 12, 2002

Reactions of [Ru(dppe)(CO)(H2O)3][OTf]2
Figure 3. ORTEX diagram of [Ru(dppe)(CO)(CNCMe3)3][OTf]2‚(acetone)
(4). Thermal ellipsoids are shown at the 30% level.
Figure 2. ORTEX diagram of [Ru(dppe)(CO)(DMSO)3][OTf]2 (3).
Thermal ellipsoids are shown at the 30% level.
Table 4. Selected Bond Lengths [Å] and Angles [deg] for
[Ru(dppe)(CO)(CNCMe3)3][OTf]2‚(acetone) (4)
Table 3. Selected Bond Lengths [Å] and Angles [deg] for
[Ru(dppe)(CO)(DMSO)3][OTf]2 (3)
Ru(1)-C(27)
Ru(1)-C(38)
Ru(1)-P(1)
1.937(3)
2.041(3)
2.3660(7) Ru(1)-P(2)
Ru(1)-C(28)
Ru(1)-C(33)
2.030(3)
2.025(3)
2.3583(7)
Ru(1)-C(1)
Ru(1)-O(4)
Ru(1)-P(2)
1.831(2)
2.1524(17)
2.2866(5)
Ru(1)-O(3)
Ru(1)-O(2)
Ru(1)-P(1)
2.1353(16)
2.1808(17)
2.2941(6)
C(27)-Ru(1)-C(33) 91.33(14) C(27)-Ru(1)-C(38) 177.42(12)
C(33)-Ru(1)-C(28) 88.76(12) C(28)-Ru(1)-C(38) 85.60(12)
C(33)-Ru(1)-C(38) 86.09(13) C(33)-Ru(1)-P(2)
C(1)-Ru(1)-O(3)
O(3)-Ru(1)-O(4)
O(3)-Ru(1)-O(2)
C(1)-Ru(1)-P(2)
O(4)-Ru(1)-P(2)
C(1)-Ru(1)-P(1)
O(4)-Ru(1)-P(1)
P(2)-Ru(1)-P(1)
176.18(9)
80.47(7)
85.21(7)
88.07(8)
168.00(5)
91.06(8)
98.25(6)
85.03(2)
C(1)-Ru(1)-O(4)
C(1)-Ru(1)-O(2)
O(4)-Ru(1)-O(2)
O(3)-Ru(1)-P(2)
O(2)-Ru(1)-P(2)
O(3)-Ru(1)-P(1)
O(2)-Ru(1)-P(1)
103.35(10)
95.20(9)
83.48(7)
88.12(4)
91.93(5)
88.33(5)
172.94(5)
94.91(9)
89.90(8)
175.79(10)
89.74(8)
84.48(3)
C(27)-Ru(1)-P(2)
C(28)-Ru(1)-P(2)
C(27)-Ru(1)-P(1)
C(28)-Ru(1)-P(1)
90.36(9)
C(38)-Ru(1)-P(2)
173.99(8) C(33)-Ru(1)-P(1)
92.84(10) C(38)-Ru(1)-P(1)
91.51(8)
P(2)-Ru(1)-P(1)
C(27)-Ru(1)-C(28) 94.31(12)
coordination sphere, which is reflected in the large Ru-O-S
angles of the equatorial DMSO ligands (121.8° and 131.4°)
relative to the axial bound group (118.5°). One of the triflate
anions shows an interaction with the hydrogens on one of
the DMSO ligands (C(28)-H(28A)‚‚‚O(7) ) 3.54 Å).
The reaction of 1 with excess Me3CNC was also found to
lead to substitution of all three waters by isocyanide affording
[Ru(dppe)(CO)(CNCMe3)3][OTf]2 (4, Figure 3). The IR
spectrum displays a single carbonyl band at considerably
higher frequency (2071 cm-1) than found for either 2 or 3.
The bond lengths and angles in 4 are unremarkable (Table
4), although the ruthenium to carbonyl carbon bond length
is significantly longer than comparable distances in either 2
or 3 (1.937(3) vs 1.870(3) and 1.831(2) Å), reflecting the
competition between CO and the three other π-acceptor
isocyanide ligands for electron density on the metal. Solvent
of recrystallization in 4 acts solely as a lattice “cement”,
although one of the triflate anions displays weak hydrogen
bonding interactions to hydrogen atoms in one of the
equatorial CNCMe3 groups (C(30)-H(30C)‚‚‚O(6) ) 3.48
Å, C(32)-H(32B)‚‚‚O(2) ) 3.40 Å).
distances found in the related ruthenium(II) complexes,
[Ru(CH3CN)6]2+ (2.028(1) Å),14 [(η5-C5H5)Ru(CH3CN)3]+
(2.083(1) Å),15 or [TpRu(CH3CN)3]+ (2.045(7) Å)16 (Tp )
hydridotris(pyrazolyl)borate). This is an indication that d f
π* bonding is much less important in 2 than in these three
other reported cases, a fact that is further supported by the
high frequency of the νCN IR absorption bands. The crystal
structure of 2 contains discrete Ru(II) cations, two triflate
anions, and solvent molecules. There is evidence for
C-H‚‚‚O interactions using the criteria of Desiraju.11 Thus,
in the lattice array, the cation is linked to both of the -OSO2-
CF3 anions via weak C-H‚‚‚O interactions involving
hydrogens in two of the bound acetonitrile groups (C(28)-
H(28A)‚‚‚O(4) ) 3.56 Å, C(32)-H(32B)‚‚‚O(6) ) 3.29 Å).
Figure 2 represents the asymmetric structure of 3, with
the relevant bond angles and distances given in Table 3. As
expected in a cationic ruthenium complex, all three DMSO
ligands are oxygen bound to the metal with Ru-O bond
lengths in the range 2.13-2.18 Å. Although O-bonded
DMSO is sterically less demanding than S-bonded DMSO,17
the cation in 3 is still subject to steric crowding in the metal
Reaction of [Ru(dppe)(CO)(H2O)3][OTf]2 with Biden-
tate Ligands (L ) 2,2′-Bipyridyl (bpy) and 4,4′-Dimethyl-
2,2′-bipyridyl (Me2bpy)). Addition of 1 equiv of 2,2′-
bipyridyl (bpy) to an acetone/water solution of 1 resulted in
the rapid formation of [Ru(dppe)(CO)(H2O)(bpy)][OTf]2, 5a,
evidenced as a singlet in the 31P{1H} NMR spectrum,
indicating that the bipyridyl ligand must be in the same plane
as the bidentate phosphine. The symmetrical structure of this
(14) Luginbu¨hl, W.; Ludi, A.; Raselli, A.; Bu¨rgi, H.-B. Acta Crystallogr.,
Sect. C 1989, C45, 1428.
(15) Luginbu¨hl, W.; Zbinden, P.; Pittet, P. A.; Armbruster, T.; Bu¨rgi, H.-
B.; Merbach, A. E.; Ludi, A. Inorg. Chem. 1991, 30, 2350.
(16) Ru¨ba, E.; Simanko, W.; Mereiter, K.; Schmid, R.; Kirchner, K. Inorg.
Chem. 2000, 39, 382.
(17) (a) Alessio, E.; Bolle, M.; Milani, B.; Mestroni, G.; Faleschini, P.;
Geremia, S.; Calligaris, M. J. Chem. Soc., Dalton Trans. 1995, 4716.
(b) Iengo, E.; Mestroni, G.; Geremia, S.; Calligaris, M.; Alessio, E. J.
Chem. Soc., Dalton Trans. 1999, 3361.
1
product was confirmed by the H NMR spectrum, which
showed only four pyridyl resonances. Species 5a readily
Inorganic Chemistry, Vol. 41, No. 12, 2002 3141

Hargreaves et al.
Scheme 1
converted in ca. 1 h, at room temperature, into an isomeric
product, 5b, which displayed two doublets in the 31P{1H}
NMR spectrum. Extensive overlap of pyridyl and phenyl
1
signals in the aromatic region of the H NMR spectrum
prevented 5b from being fully characterized using NMR
spectroscopy. Thus, the reaction of 1 with 4,4′-dimethyl-
2,2′-bipyridyl (Me2bpy) was conducted on the grounds that
the methyl substituents would give a clear spectroscopic
handle. The low-temperature 1H and 13C{1H} NMR spectra
of [Ru(dppe)(CO)(H2O)(Me2bpy)][OTf]2, 6a (recorded at 258
K to prevent isomerization), showed only a single methyl
signal as expected for a symmetrical arrangement of the two
pyridyl rings. Isomerization of 6a to 6b occurred upon
warming to room temperature to give two methyl resonances,
which were characterized in both the 1H and 13C{1H} NMR
spectra. The latter also showed a carbonyl signal at δ 199.4
split into a triplet (JCP ) 16.1 Hz), indicating that it is cis to
the dppe ligand (Scheme 1).
Synthesis and X-ray Characterization of [Ru(dppe)-
(CO)(OTf)(Me2bpy)][OTf] (7). The coordinated water
ligand in 6b proved to be labile and hence dissolution in
CDCl3 afforded [Ru(dppe)(CO)(OTf)(Me2bpy)][OTf] (7).18
The 19F NMR spectrum showed two signals in a 1:1 ratio at
-78.97 and -79.07 ppm for coordinated and uncoordinated
triflate, respectively. Complex 7 rapidly precipitated from
solution, preventing full characterization by NMR spectros-
copy. However, the structure of 7 has been unambiguously
established using X-ray crystallography. Figure 4 reveals the
contents of the asymmetric unit, while selected bond lengths
and angles are given in Table 5. The geometry about the
ruthenium center in 7 is largely dictated by the steric
demands of the chelating bipyridyl ligand (N(1)-Ru-N(2)
) 76.73(7)°).19 This results in severe distortion away from
Figure 4. ORTEX diagram of [Ru(dppe)(CO)(OTf)(Me2bpy)][OTf] (7).
Thermal ellipsoids are shown at the 30% level.
Table 5. Selected Bond Lengths [Å] and Angles [deg] for
[Ru(dppe)(CO)(OTf)(Me2Bpy)][OTf] (7)
Ru(1)-C(27)
Ru(1)-N(1)
Ru(1)-N(2)
1.869(2)
2.126(2)
2.267(2)
Ru(1)-O(2)
Ru(1)-P(2)
Ru(1)-P(1)
2.212(2)
2.2826(6)
2.3392(5)
C(27)-Ru(1)-N(1)
C(27)-Ru(1)-N(2)
N(1)-Ru(1)-N(2)
C(27)-Ru(1)-O(2)
N(1)-Ru(1)-O(2)
N(2)-Ru(1)-O(2)
C(27)-Ru(1)-P(2)
N(1)-Ru(1)-P(2)
96.25(8)
171.96(8)
76.73(7)
99.48(8)
85.26(6)
84.00(6)
90.50(7)
95.60(5)
N(2)-Ru(1)-P(2)
O(2)-Ru(1)-P(2)
C(27)-Ru(1)-P(1)
N(1)-Ru(1)-P(1)
N(2)-Ru(1)-P(1)
O(2)-Ru(1)-P(1)
P(2)-Ru(1)-P(1)
86.35(5)
169.85(5)
84.33(7)
179.11(5)
102.74(5)
93.98(4)
85.17(2)
a regular octahedral geometry as shown by the P(2)-
Ru-P(1), C(27)-Ru-N(2), and C(27)-Ru-O-(2) angles
(85.17(2)°, 171.96(8)°, and 99.48(8)°, respectively).
There are large differences in the Ru-N(1) (2.126(2) Å)
and Ru-N(2) (2.267(2) Å) distances of 7. The notable
lengthening of the latter bond arises from differing trans
(19) (a) Anderson, P. A.; Deacon, G. B.; Haarmann, K. H.; Keene, F. R.;
Meyer, T. J.; Reitsma, D. A.; Skelton, B. W.; Strouse, G. F.; Thomas,
N. C.; Treadway, J. A.; White, A. H. Inorg. Chem. 1995, 34, 6145.
(b) Eskelinen, E.; Haukka, M.; Vena¨la¨inen, T.; Pakkanen, T. A.;
Wasberg, M.; Chardon-Noblat, S.; Deronzier, A. Organometallics
2000, 19, 163.
(18) Triflate was also found to displace water from 5b to afford [Ru(dppe)-
(CO)(OTf)(bpy)][OTf] in CDCl3.
3142 Inorganic Chemistry, Vol. 41, No. 12, 2002

Reactions of [Ru(dppe)(CO)(H2O)3][OTf]2
Table 6. Selected Bond Lengths [Å] and Angles [deg] for
[{Ru(dppe)(CO)}2(µ-SCH2CH2CH3)3][OTf] (8)
Ru(1)-C(49)
Ru(1)-P(2)
Ru(1)-S(1)
Ru(2)-C(50)
Ru(2)-P(3)
Ru(2)-S(4)
1.851(2)
2.3539(5)
2.4662(5)
1.861(2)
2.3547(5)
2.4654(5)
Ru(1)-P(1)
Ru(1)-S(2)
Ru(1)-S(4)
Ru(2)-P(4)
Ru(2)-S(2)
Ru(2)-S(1)
2.3340(5)
2.4387(5)
2.4964(5)
2.3211(5)
2.4473(5)
2.4653(5)
C(49)-Ru(1)-P(1) 87.77(6)
C(49)-Ru(1)-P(2) 87.54(7)
C(49)-Ru(1)-S(2) 93.56(7)
P(1)-Ru(1)-P(2)
P(1)-Ru(1)-S(2)
82.657(18)
94.968(17)
P(2)-Ru(1)-S(2)
P(1)-Ru(1)-S(1)
S(2)-Ru(1)-S(1)
P(1)-Ru(1)-S(4)
177.346(17)
C(49)-Ru(1)-S(1) 95.30(6)
176.421(18)
83.030(16)
99.830(17)
73.711(16)
P(2)-Ru(1)-S(1)
99.279(17)
C(49)-Ru(1)-S(4) 165.59(7)
P(2)-Ru(1)-S(4)
S(1)-Ru(1)-S(4)
C(50)-Ru(2)-P(3) 89.89(6)
C(50)-Ru(2)-S(2) 94.69(6)
P(3)-Ru(2)-S(2)
P(4)-Ru(2)-S(4)
S(2)-Ru(2)-S(4)
P(4)-Ru(2)-S(1)
S(2)-Ru(2)-S(1)
Ru(2)-S(1)-Ru(1) 86.412(15)
Ru(2)-S(4)-Ru(1) 85.753(15)
105.468(17) S(2)-Ru(1)-S(4)
76.777(16)
C(50)-Ru(2)-P(4) 93.84(6)
P(4)-Ru(2)-P(3)
P(4)-Ru(2)-S(2)
83.926(17)
92.056(17)
Figure 5. ORTEX diagram of [{Ru(dppe)(CO)}2(µ-SCH2CH2CH3)3][OTf]
(8). Thermal ellipsoids are shown at the 30% level.
174.107(17) C(50)-Ru(2)-S(4) 167.23(6)
92.708(17)
74.111(16)
169.757(17) P(3)-Ru(2)-S(1)
82.871(16) S(4)-Ru(2)-S(1)
P(3)-Ru(2)-S(4)
101.709(17)
influences of the phosphine (P1) and carbonyl ligands (C27).
This is further apparent from the significant differences in
the Ru-P(1) and Ru-P(2) bond distances (2.3392(5),
2.2826(6) Å, respectively). There appears to be a weak
intramolecular interaction between a phenyl C-H and the
coordinated triflate group (C(8)-H(8)‚‚‚O(3), 3.396 Å) as
well as an intermolecular interaction between C(11)-H(11)
and O(5) of a symmetry-related anion in the lattice, at
3.451(3) Å.
Reaction of [Ru(dppe)(CO)(H2O)3][OTf]2 with 1-Pro-
panethiol. Addition of 1-propanethiol (3 equiv) to an
acetone/water solution of 1 led to an immediate color change
from clear to red. Crystallization of the product mixture gave
yellow/orange crystals which were isolated in 32% yield and
shown to be the dimeric complex [{Ru(dppe)(CO)}2(µ-SCH2-
CH2CH3)3][OTf] (8) by X-ray crystallography (eq 2).
C(50)-Ru(2)-S(1) 95.43(6)
100.411(17)
77.367(16)
Ru(1)-S(2)-Ru(2) 87.419(16)
and carbonyl carbon atoms at both ends of the molecule,
reflecting the local octahedral coordination sphere at both
metal centers. This highly distorted geometry is exemplified
in the angles subtended by the carbonyl carbon and the trans
sulfur at each of the ruthenium atoms, which have values of
165.59(7)° and 167.23(6)° for Ru(1) and Ru(2), respectively.
The metal-metal distance in 8 is 3.376 Å, which precludes
the presence of a Ru-Ru interaction.
Multinuclear NMR studies of [{Ru(dppe)(CO)}2(µ-SCH2-
CH2CH3)3][OTf] in acetone solution are consistent with the
solid-state structure. The proton NMR spectrum exhibits two
different types of propyl groups in a ratio of 1:2; a significant
chemical shift difference (∆ν ) 1.1 ppm) exists between
the methyl group resonances, with the unique CH3 appearing
at δ -0.23. 1H COSY, 1H-13C HMQC, and HMBC
experiments were used to fully assign the CH3CH2CH2-
1
signals in both the H and 13C{1H} NMR spectra. The
reaction of 1 with other thiols does not proceed in a manner
similar to the formation of 8. Both H2S and C6H11SH gave
mixtures of products that proved impossible to separate and
characterize.
The asymmetric unit in 8 (Figure 5) shows the presence
of a cationic dinuclear ruthenium(II) core bridged by the
sulfur atoms of three thiolate groups. Selected bond distances
and angles for 8 are given in Table 6. The Ru-S distances
(average 2.463(5) Å) are comparable to those reported in
the literature for [{(arene)Ru}2(µ-SPh)3]+ (arene ) hexa-
methylbenzene, p-cymene), while there is only small devia-
tion in the Ru-S-Ru angles (average 86.5°) from 90°.20
However, particularly striking is the distortion away from
an octahedral geometry at the ruthenium centers: the angles
between the carbonyl ligands and the unique thiolate lying
below the plane of the phosphines are 165.56° and 167.22°
for Ru(1) and Ru(2), respectively. When viewed along the
metal-metal vector, the structure of 8 reveals that the
bridging sulfurs are staggered with respect to the phosphorus
Reaction of [Ru(dppe)(CO)(H2O)3][OTf]2 with CO. In
contrast to the rapid displacement of the water ligands in 1
by strongly coordinating groups such as acetonitrile or
DMSO, the reaction of 1 with CO (1 atm) proceeded very
slowly with complete conversion to a single, new ruthenium-
containing complex taking place over 3 weeks at room
temperature. This product was assigned as the cationic
tricarbonyl hydride complex [Ru(dppe)(CO)3H][OTf] (9), due
to the presence of three carbonyl bands in the IR spectrum
(2110, 2062, and 2051 cm-1)21 and a triplet resonance at δ
1
-7.57 (JHP ) 17.80 Hz) in the H NMR spectrum. The
spectroscopic data are consistent with a fac arrangement of
the CO ligands and are in good agreement with that reported
by Gladfelter et al. for the PF6 salt of 9, which was
(20) (a) Dev, S.; Mizobe, Y.; Hidai, M. Inorg. Chem. 1990, 29, 4797. (b)
Schacht, H. T.; Haltiwanger, R. C.; DuBois, M. R. Inorg. Chem. 1992,
31, 1728. (c) Mashima, K.; Mikami, A.; Nakamura, A. Chem. Lett.
1992, 241, 1795.
(21) Skoog, S. J.; Jorgenson, A. L.; Campbell, J. P.; Douskey, M. L.;
Munson, E.; Gladfelter, W. L. J. Organomet. Chem. 1998, 557,13.
Inorganic Chemistry, Vol. 41, No. 12, 2002 3143

Hargreaves et al.
Scheme 2
by a signal for 9, showing coupling to 13CO. In addition to
two CO resonances for 9, the 13C{1H} NMR spectrum
indicated incorporation of 13CO into residual amounts of 1,
but, most importantly, displayed a signal for 13CO2 at δ 126.3.
The formation of 9, 13CO incorporation into 1, and evolution
of CO2 can all be rationalized by a mechanism based on
nucleophilic attack by water on a coordinated CO ligand in
1 leading to a water gas shift reaction. A postulated pathway
is shown in Scheme 2.24
Thus, the formation of 9 constitutes the trapping of an
intermediate on the cycle by addition of excess CO. This is
confirmed by the observation that reaction of [Ru(dppe)-
(12CO)3H][OTf] with 13CO results in incorporation of the
label, but does not yield 13CO2.
Figure 6. ORTEX diagram of [Ru(dppe)(CO)3H][OTf] (9). Thermal
ellipsoids are shown at the 30% level.
A number of recent examples of water gas shift chemistry
involving electrophilic non-phosphine stabilized ruthenium
carbonyl complexes have been reported.25 In most of these
cases, the isolation of hydrido complexes has proved elusive,
although Fachinetti and co-workers have been able to trap
[Ru(H2O)3(CO)2H]+ with either pyridine or ethene to give
[Ru(py)3(CO)2H]+ and [Ru(H2O)3(CO)2(C2H5)]+ respec-
tively.26
The discovery of a water gas shift mechanism as a pathway
toward production of 9 prompted us to reinvestigate the
formation of 1, which occurs via substitution of CO and
triflate in Ru(dppe)(CO)2(OTf)2 upon addition of water.8
Thus, addition of water to a chloroform solution of partially
13CO labeled Ru(dppe)(CO)2(OTf)2 resulted in the formation
of 13CO2, implying that nucleophilic attack of water on a
coordinated CO in the bis-triflate complex is also responsible
for the formation of 1.
synthesized upon hydrogen atom abstraction from Bu3SnH
by the radical cation [Ru(dppe)(CO)3]+.22 We were unable
to successfully isolate 9 from the reaction mixture, partly
due to its apparent instability in solution in the absence of
CO. However, we have prepared the complex independently
by protonation of Ru(dppe)(CO)3 with triflic acid under a
CO atmosphere. Thus, an X-ray structure determination has
been performed on this complex, although the poor quality
of the crystals and disorder in the triflate anion prevented
the structure from being solved with the same high degree
of accuracy as for the other compounds reported in this paper.
Nevertheless, the stereochemistry at the ruthenium center was
established beyond doubt and is illustrated in Figure 6. The
fac arrangement of the CO ligands imposed by the chelating
phosphine ligands contrasts with the mer geometry in the
structure of [Ru(PPh3)2(CO)3H]+ previously reported.23
The formation of [Ru(dppe)(CO)3H][OTf] from reaction
of 1 with CO was also probed by 13CO labeling. Monitoring
by 31P{1H} NMR spectroscopy showed the appearance after
3 days of an initial product believed to be [Ru(dppe)(CO)2-
(H2O)2][OTf]2, which displayed two doublets of doublets at
δ 64.5 (JPC ) 9.3 Hz, JPP ) 14.0 Hz) and 42.8 (JPC ) 102.3
Hz, JPP ) 14.0 Hz). The size of the P-C coupling constants
indicates substitution of water at an equatorial site by 13CO.
The 13C{1H} NMR spectrum showed a single 13C-enhanced
carbonyl resonance at δ 187.0 with coupling to two in-
equivalent 31P nuclei.
Conclusions
Substitution of one, two, or all three water ligands in
[Ru(dppe)(CO)(H2O)3][OTf]2 by a range of donor ligands
has been demonstrated to result in the formation of both
mononuclear and dinuclear ruthenium products. In all cases,
we have shown, at least qualitatively, that initial substitution
of the equatorial water ligands (trans to dppe) occurs. This
is in agreement with kinetic studies on trans-[Ru(NH3)4-
(24) Ford, P. C.; Rokicki, A. AdV. Organomet. Chem. 1988, 28, 139.
(25) (a) Fachinetti, G.; Funaioli, T.; Lecci, L.; Marchetti, F. Inorg. Chem.
1996, 35, 7217. (b) Lavigne, G. Eur. J. Inorg. Chem. 1999, 917. (c)
Faure, M.; Maurette, L.; Donnadieu, B.; Lavigne, G. Angew. Chem.,
Int. Ed. 1999, 38, 518. (d) Funaioli, T.; Cavazza, C.; Marchetti, F.;
Fachinetti, G. Inorg. Chem. 1999, 38, 3361. (e) Hill, A. F. Angew.
Chem., Int. Ed. 2000, 39, 130.
The 31P signals from [Ru(dppe)(CO)2(H2O)2][OTf]2 di-
minished over weeks at room temperature and were replaced
(22) Sherlock, S. J.; Boyd, D. C.; Moasser, B.; Gladfelter, W. L. Inorg.
Chem. 1991, 30, 3626.
(23) Siedle, A. R.; Newmark, R. A.; Gleason, W. B. Inorg. Chem. 1991,
30, 2005.
(26) Fachinetti, G.; Funaioli, T.; Marchetti, F. J. Organomet. Chem. 1995,
498, c20.
3144 Inorganic Chemistry, Vol. 41, No. 12, 2002

Reactions of [Ru(dppe)(CO)(H2O)3][OTf]2
(H2O)(PR3)]2+ which have established that the kinetic trans
effect of dppe is much greater than that of CO.27
(CO)2(OTf)2) and in its reaction with CO, which yields the
cationic hydride complex [Ru(dppe)(CO)3H]+. Additional
work is required to see if this underlying pathway can be
utilized further.
The triflate anion appears to play an important role in the
reactivity of 1.28 While hydrogen bonding interactions have
been reported to help stabilize many organometallic aqua
complexes, we find that OTf also plays the role of hydrogen
bond acceptor in weak C-H‚‚‚O hydrogen bonding interac-
tions in the solid-state structures of 2, 3, and 4. Dissolution
of [Ru(dppe)(CO)(H2O)(Me2bpy)][OTf]2, 6b, in nonprotic
solvents results in triflate playing an even more interactive
role in substituting water to afford 7. We are currently
engaged in studies which compare the role of triflate with
that of other anions (BF4, SbF6, NTf) in influencing the
chemistry of 1.
Acknowledgment. We thank EPSRC and the University
of Bath for financial support. We acknowledge JREI/EPSRC
for funding the CCD X-ray diffractometer and Johnson
Matthey plc for the loan of RuCl3‚xH2O. We gratefully
acknowledge the comments from a referee on an earlier
version of this paper who instigated our study of the water
gas shift chemistry associated with 1.
Supporting Information Available: Analytical and X-ray
crystallographic data including tables of atomic coordinates, bond
lengths and angles, anisotropic displacement parameters, hydrogen
coordinates and Ueq, and packing diagram. This material is available
free of charge via the Internet at http://pubs.acs.org.
Water gas shift chemistry has been shown to be important
in both the mechanism of formation of 1 (from Ru(dppe)-
(27) Franco, D. W. Coord. Chem. ReV. 1992, 119, 199.
(28) (a) Lawrance, G. A. Chem. ReV. 1986, 86, 17. (b) Beck, W.; Su¨nkel,
K. Chem. ReV. 1988, 88, 1405.
IC020029Z
Inorganic Chemistry, Vol. 41, No. 12, 2002 3145