A highly reactive ruthenium phosphide complex exhibiting Ru-P π-bonding

Article abstract of DOI:10.1021/om0700056

Multiple bonding in the terminal phosphido complex [Ru(PCy ₂)(η₅-indenyl)(PPh₃)J (2a) is clearly demonstrated by solution, solid-state, and computational studies. Reactions of this dark blue, half-sandwich complex with CO, MeI, HNEt₃Cl, HCl, NH₄PF₆, H₂, and Et₃SiH demonstrate an unusual range of behavior resulting from combined coordinative unsaturation at Ru, high nucleophilicity/basicity of the phosphido P, and π-character of the Ru-P interaction. The terminal, π-bound phosphido structure is general for a range of PR₂ species (R = Prⁱ (2b), Ph (2c), Tol^p (2d)). The very reactive diarylphosphido analogues 2c,d have been observed spectroscopically at low temperatures and can be trapped quantitatively as their CO adducts, [Ru(PAr₂)(η⁵- indenyl)(CO)(PPh₃)] (3c,d), in which the Ru-P bond order is reduced to 1. Complex 2a and its analogue [Ru(PPrⁱ₂) (η⁵-indenyl)(PPh₃)] (2b) are consistently isolated with ～15% of their structural isomers, the ruthenium hydrido phosphaalkenes 9a,b, resulting from an apparent 1,2-H shift.

Full text of DOI:10.1021/om0700056

Organometallics 2007, 26, 1473-1482
1473
A Highly Reactive Ruthenium Phosphido Complex Exhibiting Ru-P
π-Bonding
Eric J. Derrah,† Dimitrios A. Pantazis,‡ Robert McDonald,§ and Lisa Rosenberg*,†
Department of Chemistry, UniVersity of Victoria, P.O. Box 3065, Victoria, British Columbia V8W 3V6,
Canada, WestCHEM, Department of Chemistry, UniVersity of Glasgow, Glasgow G12 8QQ, United
Kingdom, and X-ray Crystallography Laboratory, Department of Chemistry, UniVersity of Alberta,
Edmonton, Alberta T6G 2G2, Canada
ReceiVed January 3, 2007
Multiple bonding in the terminal phosphido complex [Ru(PCy2)(η5-indenyl)(PPh3)] (2a) is clearly
demonstrated by solution, solid-state, and computational studies. Reactions of this dark blue, half-sandwich
complex with CO, MeI, HNEt3Cl, HCl, NH4PF6, H2, and Et3SiH demonstrate an unusual range of behavior
resulting from combined coordinative unsaturation at Ru, high nucleophilicity/basicity of the phosphido
P, and π-character of the Ru-P interaction. The terminal, π-bound phosphido structure is general for a
range of PR2 species (R ) Pri (2b), Ph (2c), Tolp (2d)). The very reactive diarylphosphido analogues
2c,d have been observed spectroscopically at low temperatures and can be trapped quantitatively as their
CO adducts, [Ru(PAr2)(η5-indenyl)(CO)(PPh3)] (3c,d), in which the Ru-P bond order is reduced to 1.
Complex 2a and its analogue [Ru(PPri2)(η5-indenyl)(PPh3)] (2b) are consistently isolated with ∼15% of
their structural isomers, the ruthenium hydrido phosphaalkenes 9a,b, resulting from an apparent 1,2-H
shift.
through the additional formation of a metal-phosphorus π-bond
(3-electron donor).5 We report herein the first fully characterized
example of a ruthenium-phosphorus double bond,6 observed
for an “unsaturated”, two-legged piano-stool complex.
Introduction
Phosphido ligands are best known in ruthenium chemistry
and elsewhere as exemplary bridging ligands (µ-PR2) in
dinuclear complexes or larger clusters.1 The few reported
examples of terminal Ru-PR2 complexes are formally 6-coor-
dinate, 18-electron complexes, with pyramidal geometry at
phosphorus indicative of a stereoactive lone pair and Ru-PR2
distances consistent with a Ru-P single bond.2 Examples in
which the lone pair on phosphorus participates in π-bonding
with the metal center are unknown for ruthenium and indeed
remain rare for groups 8-10.3 This mode of binding, which
leads to planarity at an sp2-hybridized phosphorus and a
shortened M-P distance, is not uncommon for early-metal
complexes (groups 4-7),4 where it represents an alternative to
dimerization (via µ-PR2) to offset electron deficiency and
coordinative unsaturation. Thus, complexes that are formally
16-electron species if the phosphido ligand participates only in
σ-bonding (1-electron donor) achieve an 18-electron count
Results and Discussion
Experimental and Computational Characterization of the
π-Bond in [Ru(PCy2)(η5-indenyl)(PPh3)] (2a). The mixed
phosphine complex [RuCl(η5-indenyl)(HPCy2)(PPh3)] (1a)7 is
quantitatively consumed by addition of KOBut, with loss of KCl
and ButOH. The resulting dark blue complex [Ru(PCy2)(η5-
indenyl)(PPh3)] (2a) (Scheme 1) is invariably accompanied by
a small amount of the metallaphosphaalkene hydride complex
[Ru(P{dC(-C5H10-)}Cy)(H)(η5-indenyl)(PPh3)] (9a), a struc-
(4) Examples of π-bound phosphido complexes of metals from groups
4-7 include: (a) Baker, R. T.; Calabrese, J. C.; Harlow, R. L.; Williams,
I. D. Organometallics 1993, 12, 830. (b) Baker, R. T.; Calabrese, J. C.;
Glassman, T. E. Organometallics 1988, 7, 1889. (c) Cowley, A. H.; Kemp,
R. A. Chem. ReV. 1985, 85, 367. (d) Cowley, A. H.; Giolando, D. M.;
Nunn, C. M.; Pakulski, M.; Westmoreland, D.; Norman, N. C. J. Chem.
Soc., Dalton Trans. 1988, 2127. (e) Lang, H.; Leise, M. Zsolnai, L. J.
Organomet. Chem. 1990, 389, 325. (f) Malisch, W.; Hirth, U. A.; Bright,
T. A.; Kab, H.; Ertel, T. S.; Huckmann, S.; Bertagnolli, H. Angew. Chem.,
Int. Ed. Engl. 1992, 31, 1525. (g) Malisch, W.; Hirth, U. A.; Grun, K.;
Schmeusser, M. J. Organomet. Chem. 1999, 572, 207.
* To whom correspondence should be addressed. E-mail: lisarose@uvic.ca.
† University of Victoria.
‡ University of Glasgow.
§ University of Alberta.
(1) Carty, A. J.; MacLaughlin, S. A.; Nucciarone, D. Methods Stere-
ochem. Anal. 1987, 8, 559.
(2) (a) Planas, J. G.; Hampel, F.; Gladysz, J. A. Chem. Eur. J. 2005, 11,
1402. Planas, J. G.; Gladysz, J. A. Inorg. Chem. 2002, 41, 6947. (b)
Sterenberg, B. T.; Udachin, K. A.; Carty, A. J. Organometallics 2003, 22,
3927. (c) Stasunik, A.; Wilson, D. R.; Malisch, W. J. Organomet. Chem.
1984, 270, C18. (d) Chan, V. S.; Stewart, I. C.; Bergman, R. G.; Toste, F.
D. J. Am. Chem. Soc. 2006, 128, 2786. (e) Burn, M. J.; Fickes, M. G.;
Hollander, F. J.; Bergman, R. G. Organometallics 1995, 14, 137. (f) Bohle,
D. S.; Jones, T. C.; Rickard, C. E. F.; Roper, W. R. Organometallics 1986,
5, 1612. (g) Weber, L.; Reizig, K.; Boese, R. Organometallics 1985, 4,
2097.
(3) Metals from groups 8-10 for which crystallographically characterized
π-bound phosphido complexes have been reported are limited to Co (Lang,
H.; Eberle, U.; Leise, M.; Zsolnai, L. J. Organomet. Chem. 1996, 519, 137.
Bezombes, J. P.; Hitchcock, P. B.; Lappert, M. F.; Nycz, J. E. Dalton Trans.
2004, 499) and Ni (Melenkivitz, R.; Mindiola, D. J.; Hillhouse, G. L. J.
Am. Chem. Soc. 2002, 124, 3846).
(5) π-Bound phosphido (PR2-) complexes (nucleophilic at P, three-
electron-donor ligands) are distinct from phosphenium (PR2+) complexes
(electrophilic at P, two-electron-donor ligands), which may also exhibit
π-bonding to metals by virture of their π-acidity. See: (a) Sanchez, M.;
Mazie`res, M. R.; Lamade´, L.; Wolf, R. In Multiple Bonds and Low
Coordination in Phosphorus Chemistry; Regitz, M., Scherer, O. J., Eds.;
Georg Thieme Verlag: Stuttgart, Germany, 1990; p 141. (b) Abrams, M.
B.; Scott, B. L.; Baker, R. T. Organometallics 2000, 19, 4944. (c) Nakazawa,
H. J. Organomet. Chem. 2000, 611, 349.
(6) A series of metastable Ru-phosphenium complexes exhibit 31P NMR
shifts consistent with sp2 planar phosphorus, but the extent of π-back-
bonding from Ru has not been assessed: Kawamura, K.; Nakazawa, H.;
Miyoshi, K. Organometallics 1999, 18, 4785.
(7) Derrah, E. J.; Marlinga, J. C.; Mitra, D.; Friesen, D. M.; Hall, S. A.;
McDonald, R.; Rosenberg, L. Organometallics 2005, 24, 5817.
10.1021/om0700056 CCC: $37.00 © 2007 American Chemical Society
Publication on Web 02/16/2007

1474 Organometallics, Vol. 26, No. 6, 2007
Derrah et al.
Figure 1. View of [Ru(PCy2)(η5-indenyl)(PPh3)] (2a) without
hydrogen atoms. In this and subsequent figures, non-hydrogen atoms
are represented by Gaussian ellipsoids at the 20% probability level,
C* denotes the centroid of the plane defined by C(7A)-C(1)-
C(2)-C(3)-C(3A), and ∆ (indenyl slip distortion) ) d[Ru-
C(7A),C(3A)] - d[Ru-C(1),C(3)]. Selected interatomic distances
(Å) and bond angles (deg): Ru-P(1) ) 2.1589(14), Ru-P(2) )
2.2719(12), Ru-C* ) 1.885, ∆ ) 0.117; P(1)-Ru-P(2) ) 92.62-
(5), P(1)-Ru-C* 138.4, P(2)-Ru-C* ) 128.4, Ru-P(1)-C(11)
) 129.54(17), Ru-P(1)-C(21) ) 125.44(17), C(11)-P(1)-C(21)
) 103.2(2).
Scheme 1
Figure 2. Frontier Kohn-Sham molecular orbitals calculated using
DFT (hybrid PBE1PBE) for [Ru(η5-indenyl)(PCy2)(PPh3)] (2a).
Figure 3. Occupied natural orbitals relevant to Ru-P bonds
resulting from NBO analysis of the calculated structure of 2a: (a)
Ru-PPh3 σ; (b) Ru-PCy2 σ; (c) Ru-PCy2 π.
frontier Kohn-Sham molecular orbitals (Figure 2) show a
distribution of the π-character of the ruthenium phosphide over
three valence orbitals: HOMO-2, HOMO, and LUMO. In
contrast, HOMO-1 is purely Ru-based, a 4d orbital with lobes
protruding perpendicularly on either side of the RuP2 plane.
Within the π-manifold, HOMO-2 corresponds to the Ru-P
π-bonding combination, with strong mixing with an indenyl-
based orbital, while the unoccupied π-antibonding component
defines the LUMO of the system.
To firmly establish the Ru-PCy2 bond order, we analyzed
these calculations using several different methods. An unequivo-
cal picture of the bonding in 2a emerges from natural bond
orbital (NBO) analysis,10a which clearly identifies both a σ (sd/
sp)- and a π (d/p)-bond between Ru and PCy2, as well as a
σ-bond between Ru and PPh3 (Figure 3). Calculated bond
ellipticities10b of 0.031 (Ru-PPh3) and 0.162 (Ru-PCy2) are
also consistent with the significant π-character of the ruthenium-
tural isomer that appears to be in equilibrium with 2a and is
consumed on reaction with small molecules (vide infra). Solution
NMR and X-ray crystallographic studies indicate that the major
product 2a is best viewed structurally as containing a double
bond between PCy2 and Ru, with the phosphido ligand behaving
as a three-electron donor. The 31P{1H} NMR spectrum for 2a
in d6-benzene shows the expected doublet for PPh3 at 63.4 ppm
(2JPP ) 65 Hz), but the corresponding doublet for PCy2 is at
276.3 ppm, an extreme downfield shift typical of planar “sp2”
phosphorus.4a,d,8,9 δ(HPCy2) for 1a is 68.3 ppm. The molecular
structure of 2a (Figure 1) shows the sum of angles at the
phosphido P to be 358.2°, indicating the planarity at P consistent
with π-bonding.
DFT calculations clearly reproduce the planarity of the
phosphido ligand observed crystallographically. The calculated
Ru-PPh3 and Ru-PCy2 distances also agree well with the solid-
state structure of 2a: 2.266 and 2.166 Å, respectively, compared
with 2.2719(12) and 2.1589(14) Å for the crystal structure. The
(10) (a) Reed, A. E.; Curtiss, L. A.; Weinhold, F. Chem. ReV. 1988, 88,
899. (b) The bond ellipticity parameter (ꢀ) emerges from topological analysis
of electron density associated with molecular bonds; it is a quantitative
measure of the deviation of the electron distribution from cylindrical
symmetry, i.e. of the amount of π-character of a bond. Benchmark ꢀ values
are 0.000 and 0.298 for the C-C bonds of ethane and ethylene, respectively.
Bader, R. F. W. Atoms in Molecules: A Quantum Theory; Oxford University
Press: Oxford, U.K., 1994. (c) Wiberg bond indices provide an indication
of the relative bond order between specific atom pairs and are calculated
on the basis of the orthonormal natural atomic orbitals produced by the
NBO analysis. Wiberg, K. B. Tetrahedron 1968, 24, 1083.
(8) Hutchins, L. D.; Paine, R. T.; Campana, C. F. J. Am. Chem. Soc.
1980, 102, 4521.
(9) A downfield 31P shift of 185.8 ppm was reported for a rhodium tris-
(phosphine) complex containing the PCy2 ligand. Although this terminal
phosphido complex was not structurally characterized, computational studies
on the simple model (H3P)3RhPH2 point to significant P (p)-Rh (p)
π-interactions, leading to preferential stabilization of, and contribution of,
a rotamer in which the P3Rh and PH2 fragments are entirely coplanar.
Dahlenburg, L. Ho¨ck, N.; Berke, H. Chem. Ber. 1988, 121, 2083.

A Ruthenium-Phosphorus Double Bond
Organometallics, Vol. 26, No. 6, 2007 1475
Scheme 2
Figure 4. Molecular structure of [Ru(PCy2)(η5-indenyl)(CO)-
(PPh3)] (3a). Selected interatomic distances (Å) and bond angles
(deg): Ru-P(1) ) 2.4390(7), Ru-P(2) ) 2.3158(6), Ru-C* )
1.973, ∆ ) 0.154; P(1)-Ru-P(2) ) 90.92(2), P(1)-Ru-C* )
125.8, P(2)-Ru-C* ) 125.4, Ru-P(1)-C(11) ) 107.36(8), Ru-
P(1)-C(21) ) 107.88(8), C(11)-P(1)-C(21) ) 102.47(10).
of dark red [Ru(PCy2)(η5-indenyl)(CO)(PPh3)] (3a) on addition
of CO(g) to 2a (Scheme 2 (middle) and Figure 4). Loss of the
Ru-P π-bond in this transformation is strikingly demonstrated
by an increase of almost 0.3 Å in the Ru-PCy2 distance in 3a
relative to 2a and by a ∼200 ppm upfield shift of the 31P peak
for PCy2 in 3a relative to 2a, consistent with a change from
planar to tetrahedral geometry at the terminal phosphido ligand.14
phosphido interaction. Finally, for Ru-PCy2 the calculated
Wiberg bond index,10c a relative measure of bond order, is
exactly double that for Ru-PPh3 (1.18 vs 0.59), confirming the
presence of the RudP double bond.
The Ruδ+dPδ- bond polarity is indicated by a series of
reactions (Scheme 2 (top)), including that of 2a with MeI, in
which Meδ+ is delivered to the phosphido ligand and Iδ-
coordinates to ruthenium, to generate [Ru(η5-indenyl)(I)-
(MePCy2)(PPh3)] (4a). The phosphido ligand in 2a can also be
protonated by HNEt3Cl: this delivers Cl- to the more electro-
positive, unsaturated ruthenium, regenerating orange 1a. This
reaction may proceed via the cationic triethylamine adduct [Ru-
(η5-indenyl)(HPCy2)(NEt3)(PPh3)]+ (5a‚NEt3). Structural evi-
dence for this intermediate was obtained by adding NH4PF6 to
2a, which allowed isolation of yellow crystals of the ammine
complex [Ru(η5-indenyl)(HPCy2)(NH3)(PPh3)]+ (5a‚NH3) as its
The dark blue color of 2a places it among an interesting and
limited series of two-legged piano-stool ruthenium com-
plexes.11,12 Of these, 2a is the first structurally characterized
example containing either an η5-indenyl ligand or a terminal
phosphido ligand. These five-coordinate compounds are invari-
ably planar at ruthenium (see Figure 1 for relevant angles) and
typically include at least one X ligand (e.g., halide, alkoxide,
amido, and thiolato ligands) with a lone pair able to interact in
a π-fashion with the ruthenium. The extent of this π-bonding
can vary considerably,13 yet these intensely colored complexes
all exhibit reactivity dominated by coordinative unsaturation at
ruthenium (vide infra).11 The UV spectrum of 2a in either
toluene or diethyl ether shows a band at 590 nm (ꢀ ) 1700),
which is responsible for its deep blue color. Time-dependent
DFT calculations suggest this band corresponds largely to the
HOMO-LUMO transition (n to π*), for which there is no net
transfer of charge. A second band at 370 nm (ꢀ ) 10 000)
corresponds to the HOMO-2-LUMO transition (π to π*), but
again, charge transfer does not play a role.
-
PF6 salt (Figure 5). Protonation of 2a by ethereal HCl also
gives 1a as the major product, but an increase in the proportion
of byproducts is observed, presumably reflecting the high
reactivity of an unsaturated fragment of the formula [Ru(η5-
indenyl)(HPCy2)(PPh3)]+.15
Further evidence for the combined PCy2 basicity and func-
tional unsaturation of complex 2a comes from its thermal
(solution) transformation into ortho-metalated 6a (Scheme 2
(bottom left)).16 Also, while other examples of blue “unsatur-
ated” ruthenium complexes are notable for their ability to
coordinate η2-H2 or for their susceptibility to oxidative addition
reactions leading to Ru(IV) complexes,11 addition of H2 or
HSiEt3 to 2a leads instead to effective 1,2-addition across the
Reactions of [Ru(PCy2)(η5-indenyl)(PPh3)] (2a). Although
2a is formally an 18-electron complex, it behaves as a
coordinatively unsaturated analogue of the highly P-basic/
nucleophilic ruthenium phosphido complexes reported recently
by Gladysz and co-workers, [Ru(PR2)(η5-C5H5)(PR′3)2].2a Func-
tional unsaturation at Ru is demonstrated by ready formation
(11) Dark blue, black, or purple complexes of the formula [Ru(η5-C5-
Me5)(X)(L)] are reviewed in: Jimenez-Tenorio, M.; Puerta, M. C.; Valerga,
P. Eur. J. Inorg. Chem. 2004, 17.
(14) Very low 2JPP values in 3a are also similar to those reported in ref
2a, for mixed PR2/PR′3 complexes of Ru. Similar shift and coupling constant
changes were also observed for complexes 3c,d.
(12) Dark blue or black complexes of the formula [Ru(X)2(η6-arene)]
include: (a) Mashima, K.; Kaneyoshi, H.; Kaneko, S.; Mikami, A.; Tani,
K.; Nakamura, A. Organometallics 1997, 16, 1016. (b) Haack, K. J.;
Hashiguchi, S.; Fujii, A.; Ikariya, T.; Noyori, R. Angew. Chem., Int. Ed.
1997, 36, 285.
(15) The high reactivity of [Ru(η5-C5R5)(PR′3)2]+ complexes is well-
described in ref 11.
(16) The presence of ortho-metalated PPh3 is diagnosed in 6a by an
upfield shift of 84 ppm for δ(31P) relative to 2a. Garrou, P. E. Chem. ReV.
1981, 81, 229. We have observed peaks due to the analogous decomposition
product, 6b, in NMR samples of 2b that have sat at room temperature for
several hours. 31P{1H} NMR (145.80 MHz, δ): 66.5 (d, JPP ) 28 Hz, HPi-
Pr2), -20.8 (d, PPh3).
(13) Dark blue Ru piano-stool complexes in which both “legs” are L-type
ligands, and thus incapable of π-donation to Ru, have also recently been
reported.11

1476 Organometallics, Vol. 26, No. 6, 2007
Derrah et al.
Scheme 3
Figure 5. View of the complex cation 5a‚NH3, [Ru(η5-indenyl)-
(NH3)(HPCy2)(PPh3)]+. The hydrogen atoms attached to P(1) and
N are shown with arbitrarily small thermal parameters; other
hydrogen atoms are not shown. The hydrogen atom attached to P1
was located and freely refined. Selected interatomic distances (Å)
and bond angles (deg): Ru-P(1) ) 2.3309(5), Ru-P(2) ) 2.2717-
(5), Ru-N ) 2.1896(17), Ru-C* ) 1.905, P(1)-H(1P) ) 1.30-
(2), ∆ ) 0.134; P(1)-Ru-P(2) ) 91.531(18), P(1)-Ru-N )
89.60(5), P(2)-Ru-N ) 92.13(5), C*-Ru-P(1) ) 127.2, C*-
Ru-P(2) ) 124.6, C*-Ru-N ) 121.6.
polar and nonpolar unsaturated organic fragments, leading to
P-C bond formation,20 are now underway and will be reported
in due course.
Generality of RudPR2 Bonding. The analogous terminal
phosphido complex [Ru(PPri2)(η5-indenyl)(PPh3)] (2b) is ob-
tained when KOBut is added to the secondary phosphine
complex 1b,21 which contains HPPri2 (Scheme 3). The Ru-
PPri2 π-bond is readily diagnosed by 31P{1H} NMR, which
shows a peak due to the phosphido ligand at the extreme
downfield shift of 288.3 ppm. Unsurprisingly, when the bulky
Cy and Pri groups in 2a,b are replaced by aryl substituents, the
resulting complexes 2c,d (R ) Ph (c), Tolp (d)) are much more
reactive. They have been observed by 31P NMR spectroscopy
at low temperature but decompose quickly at room temperature
to a number of unidentified products. However, both of these
complexes can be trapped quantitatively as their CO adducts
3c,d14 by addition of KOBut to 1c7 and 1d21 under an
atmosphere of carbon monoxide. These reactions point to the
ready formation of the terminal phosphido complexes and their
fast reaction with available L-donor ligands.
Figure 6. View of [Ru(η5-indenyl)(SiEt3)(HPCy2)(PPh3)] (8a). The
phosphine hydrogen atom H(1P) (located and freely refined) is
shown with an arbitrarily small thermal parameter; other hydrogen
atoms are not shown. Selected interatomic distances (Å) and bond
angles (deg): Ru-P(1) ) 2.2790(7), Ru-P(2) ) 2.2802(7), Ru-
Si ) 2.4108(8), Ru-C* ) 1.965, P(1)-H(1P) ) 1.32(3), ∆ )
0.199; P(1)-Ru-P(2) ) 96.05(3), P(1)-Ru-Si ) 86.27(2), P2-
Ru-Si ) 96.19(2), C*-Ru-P(1) ) 127.9, C*-Ru-P(2) ) 125.0,
C*-Ru-Si ) 115.5.
Structural Isomerism at Ru-Bound sp2 Phosphorus.
Complex 2a is invariably accompanied by a small amount of a
hydride-containing species that we have identified as the
metallaphosphaalkene complex [Ru(P{dC(-C5H10-)}Cy)(H)-
(η5-indenyl)(PPh3)] (9a) (Scheme 4). The structural isomerism
of 2a and 9a is supported by mass spectrometric analysis of
the mixture, and the continued presence of sp2-hybridized
phosphorus in 9a is indicated by a signal at 243.3 ppm in the
31P{1H} NMR spectrum. Likewise, complex 2b is consistently
accompanied by ∼16% of the structural isomer [Ru(P{d
C(CH3)2}Pri)(H)(η5-indenyl)(PPh3)] (9b) (δ(31P) 256.4 ppm).
As shown in Figure 7, signals in the alkyl region of the 1H and
1H{31P} NMR spectra are particularly diagnostic of the phos-
Ruδ+dPδ- double bond, to generate complexes 7a7 and 8a
(Figure 6), respectively (Scheme 2 (bottom right)).17
Computational and experimental studies are underway to
probe whether these reactions rely on an equilibrium between
2a and a 16-electron intermediate, where loss of the Ru-P
π-bond gives a vacant coordination site at Ru and an extremely
basic lone pair at now-pyramidal PR2,18 or on a concerted
process initiated by nucleophilic attack of the PCy2 group in
2a at the hydrogen of each of these E-H bonds (E ) Cl, C, H,
Si). This behavior is also relevant in the context of base-
promoted catalytic hydrophosphination by group 8 metals.19
Cycloaddition reactions of the RudP double bond in 2a-d with
1
phaalkene structure of 9b, as confirmed by COSY and H/13C
HSQC and HMBC experiments. Two sets of signals are
observed for diastereotopic Pri groups in the major isomer 2b,
(19) (a) Jerome, F.; Monnier, F.; Lawicka, H.; Derien, S.; Dixneuf, P.
H. Chem. Commun. 2003, 696. (b) Malisch, W.; Klupfel, B.; Schumacher,
D.; Nieger, M. J. Organomet. Chem. 2002, 661, 95. (c) Wicht, D. K.;
Glueck, D. S. In Catalytic Heterofunctionalization; Togni, A., Gruetzmacher
H. J., Eds.; Wiley-VCH: Weinheim, Germany, 2000; pp 143-170.
(20) A range of cycloaddition reactions at π-bound phosphido ligands
on W and Mo have been reported by Malisch et al. See for example: (a)
Malisch, W.; Grun, K.; Fey, O.; El Baky, C. A. J. Organomet. Chem. 2000,
595, 285. (b) Malisch, W.; El Baky, C. A.; Grun, K.; Reising, J. Eur. J.
Inorg. Chem. 1998, 1945. (c) Malisch, W.; Grun, K.; Fried, A.; Reich, W.;
Pfister, H.; Hutter, G.; Zsolnai, L. J. Organomet. Chem. 1998, 566, 271.
(d) Malisch, W.; Hahner, C.; Grun, K.; Reising, J.; Goddard, R.; Kruger,
C. Inorg. Chim. Acta 1996, 244, 147.
(17) Similar reactions of H2(g) were observed previously at nucleophilic
terminal phosphido complexes of Ir (Fryzuk, M. D.; Bhangu, K. J. Am.
Chem. Soc. 1988, 110, 961) and Rh.9
(18) Spectroscopic evidence for an equilibrium between the pyramidal
phosphido complex [OsCl(PHPh)(CO)2(PPh3)2] and an isomer exhibiting
planar binding at phosphorus, [Os(PHPh)(CO)2(PPh3)2]+Cl-, has been
reported; however, this putative cationic intermediate exhibits umpolung
at P, behaving formally as an electrophilic PHPh+ complex. Bohle, D. S.;
Jones, T. C.; Rickard, C. E. F.; Roper, W. R. J. Chem. Soc., Chem. Commun.
1984, 865.
(21) Data for 1b are as follows. 31P{1H} NMR (145.79 MHz, δ): 75.9
(d, JPP ) 44 Hz, PiPr2), 51.0 (d, PPh3). Data for 1d are as follows. 31P{1H}
NMR (145.79 MHz, δ): 49.8 (d, JPP ) 49 Hz, PTolp ), 47.4 (d, PPh3).
2

A Ruthenium-Phosphorus Double Bond
Organometallics, Vol. 26, No. 6, 2007 1477
Scheme 4
while the smaller peaks due to 9b show that both the Pri methyl
groups and the PdC(CH3)2 methyl groups in this minor isomer
are diastereotopic.
The isomer ratios of 2a/9a and 2b/9b, determined by solution
31P{1H} NMR spectroscopy, are consistent over a range of crude
and recrystallized samples, which suggests that the two com-
Figure 7. 500.13 MHz 1H and 1H{31P} NMR spectra of an 84:16
mixture of 2b and 9b in d6-benzene (asterisks indicate signals due
to pentane, with which the complex mixture cocrystallizes).
1
plexes are in equilibrium. However, VT-NMR studies and H
and 31P EXSY experiments for 2a/9a provide no evidence for
this equilibrium in solution on the NMR time scale. The relative
amount of 9b drops to 14% in the low-temperature 31P{1H}
butoxide, ammonium hexafluorophosphate, triethylamine hydro-
chloride, triethylsilane and 2 M ethereal hydrogen chloride were
purchased from Aldrich Chemical Co. and used as received without
further purification. Carbon monoxide and hydrogen gas were
purchased from Praxair Canada Inc.; hydrogen gas was passed
through a drying/deoxygenating column containing activated mo-
lecular sieves (4 Å) and copper beads prior to use. [Ru(η5-indenyl)-
Cl(HPR2)(PPh3)2] (1a (R ) Cy), 1c (R ) Ph)) were prepared as
previously reported in the literature;7 complexes 1b (R ) Pri) and
1d (R ) Tolp) were prepared with 90-95% purity using the same
method21 and were used without further purification. (All secondary
phosphines were purchased from Strem Chemicals as 10 wt %
solutions in hexanes (concentrations checked against a known
quantity of triphenylphosphine oxide by 31P{1H} NMR before use),
except for di-p-tolylphosphine, which was purchased neat.) NMR
spectra were recorded on a Bruker Avance 500 instrument operating
1
NMR spectrum of 2b/9b in d8-toluene, and H EXSY on this
mixture at room temperature shows very low intensity correla-
tion between the Pri-derived methyl signals for the two isomers,
but these results are not significant within experimental error.
Consistent with slow conversion between isomers 2 and 9 in
solution on the NMR time scale, DFT calculations on the simp-
lified model complexes [RuCp(PHMe)(PH3)] and [RuCp(H)-
(PHCH2)(PH3)] show the hydrido isomer to be 9.8 kcal/mol
higher in energy, which roughly accounts for the smaller ob-
served amount of 9, and give a transition state connecting the
two species for which the barrier from [RuCp(PHMe)(PH3)] is
60.7 kcal/mol. We continue to probe the mechanism of forma-
tion and/or exchange of these isomers, which may derive from
base-catalyzed (i.e., occurring during the synthesis of 2, in the
presence of OBut-) or photolytically induced 1,2-H-shifts. We
presume that purified 2 and 9 are in equilibrium but exchange
relatively slowly in solution and that the consistent isomer ratios
observed following various reaction/precipitation procedures
suggest that the two isomers have remarkably similar solubilities.
1
at 500.13 MHz for H, 125.77 MHz for 13C, 202.46 MHz for 31P,
and 99.36 MHz for 29Si or on a Bruker Avance 360 operating at
145.80 MHz for 31P. Unless otherwise noted, chemical shifts are
1
reported in ppm at ambient temperature. H chemical shifts are
referenced to residual protonated solvent peaks at 7.16 (C6D5H),
2.09 (PhCD2H), 7.24 (CHCl3), and 5.32 ppm (CDHCl2). 13C
chemical shifts are referenced to C6D6 at 128.4 ppm, CDCl3 at 77.5
ppm, and CD2Cl2 at 54.0 ppm. All 1H, 13C, and 29Si chemical shifts
are reported relative to tetramethylsilane, and 31P chemical shifts
are reported relative to 85% H3PO4(aq). Microanalysis was
performed by Canadian Microanalytical Service Ltd., Delta, BC,
Canada. Melting/decomposition temperatures are uncorrected for
ambient pressure. Inert-atmosphere MALDI-MS was carried out
by Prof. Deryn E. Fogg and Johanna Blacquiere, Department of
Chemistry, University of Ottawa.
Conclusion
We have prepared a series of coordinatively unsaturated,
terminal phosphido complexes of ruthenium in which the
presence of a Ru-P double bond provides interesting new
pathways of reactivity. These complexes are of interest not only
as models for intermediates in hydrophosphination but also in
the context of Ru-mediated catalysis in general (e.g., transfer
hydrogenation, olefin metathesis, olefin cyclopropanation), given
the importance of, and analogy to, other Ru-ligand multiple
bonds (RudN, RudC).
1H and 13C{1H} NMR data are given in Tables 1 and 2, and
crystal data are given in Table 3.
Preparative-Scale Reactions.
(a) [Ru(PCy2)(η5-indenyl)(PPh3)] (2a). Method A. To a dark red
solution/suspension of 1a (500 mg, 0.70 mmol) in toluene (20 mL)
was added KOBut (95 mg, 0.85 mmol, 1.2 equiv). The resulting
dark blue solution was stirred for 16 h, the solvent was removed
under vacuum, and the dark blue residue was dissolved in hexanes
(200 mL) and this solution filtered through Celite to remove solid
impurities. The hexanes were removed under vacuum, and the green-
black powder was washed with cold pentane (3 × 10 mL, -25 °C)
to give a dark blue powder (208 mg, 0.31 mmol, 44%). This product
(containing 2a and 9a in an 88:12 ratio) is clean by 1H NMR, but its
extreme air sensitivity has precluded satisfactory elemental analysis.
Data for 2a are as follows. 31P{1H} NMR (202.46 MHz, δ):
276.3 (d, JPP ) 65 Hz, PCy2), 63.4 (d, PPh3). Data for 9a are as
Experimental Section
General Considerations. Unless otherwise noted, all reactions
and manipulations were performed under nitrogen in an MBraun
Unilab 1200/780 glovebox or using conventional Schlenk tech-
niques. All solvents were sparged with nitrogen for 25 min and
dried using an MBraun Solvent Purification System (SPS). Deu-
terated solvents were purchased from Canadian Isotope Labs (CIL),
freeze-pump-thaw-degassed, and vacuum-transferred from sodium/
benzophenone (d6-benzene, d8-toluene) or calcium hydride (d-
chloroform, d2-dichloromethane) before use. Potassium tert-

1478 Organometallics, Vol. 26, No. 6, 2007
η5-C7H9
Derrah et al.
1
Table 1. 500.13 MHz H NMR Data at 300 Ka
H7, H4
H6, H5
H2
H3, H1
PPh3
other
1bb
7.55 (d, 1H, 9)
6.37 (d, 1H, 8)
7.38 (t, 1H, 7) 5.34-5.33
6.91 (t, 1H, 7) (m, 1H)
4.14 (s, 1H) 7.29-7.24
3.52 (s, 1H) (om, 9H, Hm,p
HPPri2: 4.16 (dt, 1H, 351, 4, PH),
2.59 (d octet, 1H, 4, 7, CH),
)
7.03 (br s, 6H, 69, Ho)
1.95 (d octet, 1H, 1, 8, CH), 1.26 (dd, 3H, 15, 7, CH3),
1.23 (dd, 3H, 15, 7, CH3), 1.14 (dd, 3H, 15, 8, CH3),
0.83 (dd, 3H, 13, 8, CH3)
1db
7.54-7.50
(m, 3H,
7.32 (t, 1H, 7) 5.04 (t, 1H, 5) 4.75-4.76
7.30-7.24 (m,
HPTolp : 6.68 (dd, 1H, 375, 3, PH),
7.54-7.50 (m, 3H, overlaps H7, Ho),
7.10-7.08 (m, 4H, Hm), 6.71-6.66 (m, 2H, Ho),
2.32 (s, 3H, CH3) 2.43 (s, 3H, CH3)
2
6.91 (t, 1H, 7)
(m, 1H)
3H, Hp)
overlaps Ho
3.34 (s, 1H) 7.15-7.13 (m,
(Tolp))
6H, Hm)
6.43
6.80 (br s, 6H, 43, Ho)
(dd, 1H, 9, 1)
2ac
6.79-6.77
(m, 2H)
6.72-6.68
(m, 2H)
5.36 (t, 1H, 2) 5.12 (d, 2H, 2) 7.06-7.03
(om, 9H, Hm,p
7.75-7.65 (m, 6H, Ho)
PCy2: 2.45-2.35 (om), 1.99-1.89 (br m),
1.51-1.41 (br m), 1.25-1.15 (om),
0.42-0.32 (br m)
)
2bc
3ac
6.79-6.77
6.69-6.67
5.34 (s, 1H) 5.04 (s, 2H) 7.03 (br s, 9H, 7, Hm,p) PPri2: 2.56-2.49 (om, 1H, CH),
7.67-7.62 (m, 6H, Ho) 1.45 (dd, 7H, 13, 7, CH3,CH), 0.51 (t, 6H, 9, CH3)
(m, 2H)
(m, 2H)
7.28 (dm, 1H, 10) 6.96 (t, 1H,
5.89 (dm, 1H, 10)
5.91-5.90
5.29 (m, 1H) 7.03-6.98
PCy2: 2.38-2.36 (m), 2.22-2.14 (m),
2.08-1.98 (m), 1.86-1.84 (m),
1.75-1.72 (m), 1.63-1.40 (m),
1.35-1.15 (m), 1.01-0.93 (m)
10)
6.54 (t, 1H,
10)
(m, 1H)
4.90-1.89
(om, 9H, Hm,p)
(m, 1H)
7.16 (br, under solvent
peak, Ho)
3cc
3dc
4ac
7.29 (d, 1H, 9)
5.81 (d, 1H, 9)
6.99-6.92
(om, 1H,
overlaps
5.60-5.58
5.31 (s, 1H) 6.99-6.92
PPh2: 7.91-7.88 (m, 2H, Ho),
7.20-7.15 (om, 5H, Ho,m,p),
(m, 1H)
4.22 (s, 1H)
(om, 9H, Hm,p
,
overlaps H6)
6.80 (br t, 6H, 9, Ho)
7.09 (t, 2H, 8, Hm), 7.03 (t, 1H, 8, Hp)
H
m,p (PPh3))
6.58 (t, 1H, 8)
7.29
(dd, 1H, 9, 1)
5.87
7.02-6.9 (om, 5.66-5.64
5.38-5.37
(m, 1H)
4.29-4.28
(m, 1H)
7.02-6.9 (om, 9H,
PTolp : 7.86 (dd, 2H, 9, 5, Ho), 7.16-7.14 (m, 2H, Ho),
2
1H, overlaps
(m, 1H)
Hm,p, overlaps Hm
7.03 (br d, 2H, 8, Hm), 7.02-6.9 (om, 2H,
overlaps Hm,p (PPh3), and H6), 2.23 (br s, 3H, 2, CH3),
2.16 (br s, 3H, 3, CH3)
H
H
m (PTolp ),
m,p (PPh3))
(PTolp ) and H6)
2
2
(dd, 1H, 9, 1)
6.84 (t, 9, Ho)
6.60 (t, 1H, 8)
7.66 (d, 1H, 9)
6.63 (d, 1H, 8)
7.19 (t, 1H, 8) 5.12-5.11
6.87 (t, 1H, 7) (m, 1H)
5.22 (s, 1H) 7.04 (br s, 9H,
PMeCy2: 2.54-2.48 (m),
4.04 (s, 1H)
25, Hm,p
)
2.05-1.92 (m), 1.80-1.79 (m),
1.73-1.69 (m), 1.62-1.58 (m),
1.50-0.93 (m), 0.93 (d, 3H, 10, PCH3)
7.57 (br in
baseline, Ho)
d
5a‚NH3 7.60 (d, 1H, 8)
7.52-7.46
(om, 4H,
overlaps Hp)
7.14 (t, 1H, 8)
4.20 (s, 1H) 5.28 (q,
7.43-7.40 (m,
6H, Hm)
7.52-7.46 (om,
4H, Hp,
overlaps H6)
6.78 (br s, 6H, 26, Ho) NH3: 1.65 (br s, 3H, 9)
HPCy2: 3.91 (ddd, 1H, 325, 6, 3,
PH). 2.12-2.05 (m), 1.99-1.90 (m),
1.81-1.79 (m), 1.72-1.71 (m),
1.61-1.50 (m), 1.43-0.98 (m),
0.84-0.75 (m)
6.52 (dd, 1H, 8, 1)
1H, 3)
5.23-5.21
(m, 1H)
6ac,e
4.91 (s, 1H) 5.25 (s, 1H) 7.92 (t, 2H, 9, Ho)
5.190 (s, 1H) 7.44-7.34 (m),
7.26-7.00 (m),
HPCy2: 3.84 (dm, 1H, 317, PH),
1.75-1.37 (m), 1.24-0.75 (m),
0.51-0.47 (m)
6.93-6.86 (m)
8ab
7.37 (d, 1H, 10) 6.84 (t, 1H, 10) 5.70 (s, 1H) 5.02 (s, 1H) 7.22-7.20 (br om,
HPCy2: 4.42 (dd, 1H, 375, 5, PH),
2.38-2.36 (m), 2.03-2.00 (m),
6.16 (d, 1H, 5)
7.04 (t, 1H, 5)
4.31 (s, 1H)
9H, Hm,p)
7.50-6.50 (br in
baseline, Ho)
1.93-1.90 (m), 1.87-1.83 (m),
1.73-1.66 (m), 1.62-1.57 (m),
1.45-1.1 (m), 1.02-0.94 (m), 0.72-0.52 (m)
SiEt3: 0.88 (t, 9H, 8, CH3), 0.72-0.52 (m, 3H, CH2),
0.44-0.36 (m, 3H, CH2)
9ac
9bc
6.97 (d, 1H, 8)
6.67 (d, 1H, 8)
7.34 (t, 1H, 8) 5.66 (s, 1H)e 4.54 (s, 1H)f 7.45-7.42 (m,
Ru-H: -15.89 (dd, 1H, 35, 33)
all other peaks under signals for 2a
PdC(CH3)2(iPr): 2.61-2.50 (om, 1H, CH),
1.92 (d, 3H,20, dC(CH3)), 1.60 (d, 3H, 27, dC(CH3)),
1.01(dd, 3H, 15, 7, CH3),
6.92 (t, 1H, 8)
6H, Ho)
5.63 (s, 1H) 5.12 (s, 1H) 7.43-7.39 (m,
4.56 (s, 1H)
6H, Ho)
0.67 (dd, 3H, 15, 7, CH3)
Ru-H: -15.86 (t, 1H, 35)
all other peaks under
signals for 2b
a δ values are given in ppm; in parentheses are given the multiplicity, relative intensity, and Jav or ω1/2 values in Hz. om ) overlapping multiplets. The
indenyl numbering scheme is as follows:
b Sample in CDCl3. c Sample in C6D6. d Sample in CD2Cl2. e Unassigned indenyl protons are indistinguishable from phenyl protons. f Tentative assignment.

A Ruthenium-Phosphorus Double Bond
Organometallics, Vol. 26, No. 6, 2007 1479
Table 2. 125.77 MHz 13C{1H} NMR Data at 300 Ka
η5-C9H7
C3a,C7a ∆δ (C3a,7a
b
C6, C5
C7, C4
)
C2
C3, C1
PPh3
other
HPiPr2: 30.4 (d, 26, PCH),
1bc
1dc
127.1 (s) 124.8 (s) 110.7 (d, 5) -21.0 (av) 84.1 (s)
127.0 (s) 123.9 (s) 108.8 (d, 4)
65.6 (d, 11) Ci (br, under Co),
61.2 (s)
134.2 (br, 5, Co),
129.4 (s, Cp),
26.8 (dd, 25, 3, PCH),
23.2 (d, 5, CH3), 23.1 (s, CH3),
22.2 (s, CH3), 19.0 (s, CH3)
127.7 (d, 9, Cm)
127.1 (s) 124.8 (s) 111.4 (d, 4) -20.9 (av) 87.8 (s)
68.8 (d, 11) Ci (br, under Co),
HPTolp : 140.3 (d, 4, Cp), 139.6 (d, 4, Cp),
2
126.9 (s) 123.8 (s) 109.0 (d, 4)
62.0 (s)
66.1 (s)
134.0 (br, 47, Co),
129.3 (s, Cp),
127.6 (d, 10, Cm)
131.7 (dd, 35, 5, Ci), 131.2(d, 40, Ci),
133.0 (d, 9, Co), 132.7 (d, 9, Co),
129.3 (d, 9, Cm), 128.9 (d, 11, Cm),
21.7 (s, CH3), 21.6 (s, CH3)
2ad
2bd
3ad
125.7 (s) 122.7 (s) 99.6 (s)
125.6 (s) 122.8 (s) 99.8 (s)
-31.1
-30.9
76.3 (s)
141.6 (d, 36, Ci),
135.8 (d, 13, Co),
129.7 (s, Cp),
PCy2: 50.8 (d, 7, PCH), 46.1 (s, PCH)
others: 32.3 (s), 32.1 (s),
27.9-27.7 (om), 27.0-26.9
(om), 26.4 (s), 23.4 (s), 14.7 (s)
PiPr2: 39.62 (s, PCH),
34.0 (s, PCH), 22.8 (s, CH3),
17.4 (d, 10, CH3)
127.7 (d, 9, Cm)
76.4 (d, 5) 65.9 (s)
141.6 (d, 38, Ci)
135.9 (d, 13, Co),
129.3 (s, Cp),
127.7 (d, 10, Cm)
126.2 (s) 122.9 (s) 113.7 (s)
124.7 (s) 121.6 (s) 110.9 (s)
-18.4 (av) 99.8 (s)
79.3 (s)
135.3 (d, 42, Ci),
PCy2: 42.1 (d, 44, PCH), 39.0 (dd, 43, 4, PCH)
others: 37.3 (d, 29), 35.1 (d, 19), 34.0 (d, 19),
30.95 (s), 29.6 (s), 29.4 (d, 15), 28.9 (d, 9),
28.3 (d, 9), 27.5 (d, 18)
71.7 (d, 7) 134.6
(dd, 11, 3, Co),
130.1 (s, Cp),
128.2 (d, 10, Cm)
CO: 205.9 (dd, 17, 12)
3cd
3dd
126.5 (s) 123.7 (s) 114.5 (s)
125.3 (s) 122.2 (s) 110.3 (s)
-18.3 (av) 104.3 (s) 79.7 (s)
134.8 (d, 45, Ci),
73.6 (d, 9) 134.7 (d, 10 Co),
130.2 (d, 1, Cp),
PPh2: 152.7 (dd, 45, 5, Ci), 148.4 (d, 50, Ci),
136.3 (d, 23, Co), 133.1 (d, 18, Co), 128.6 (s, Cm),
128.3 (s, Cm), 127.9 (s, Cp), 125.5 (s, Cp)
CO: 205.8 (dd, 16, 10)
128.2 (d, 9, Cm)
126.4 (s) 123.7 (s) 114.8 (s)
125.2 (s) 122.1 (s) 110.4 (s)
-18.1 (av) 104.8 (s) 79.8 (s)
134.9 (d, 58, Ci),
73.6 (d, 8) 134.8 (d, 11, Co),
130.2 (d, 1, Cp),
PTolp : 149.0 (dd, 45, 5, Ci), 145.0 (d, 48, Ci),
2
137.4 (s, Cp), 136.3 (d, 23, Co), 133.3 (d, 18, Co),
129.1 (os, Cm), 128.7 (s, Cp),
128.2 (d, 10, Cm)
21.7 (s, CH3), 21.6 (s, CH3)
CO: 206.0 (dd, 18, 16)
4ad
128.0 (s) 127.0 (s) 111.0 (d, 4) -21.1 (av) 86.4 (s)
127.3 (s) 125.3 (s) 108.3 (s)
66.7 (s)
135.2 (br, Ci),
PMeCy2: 45.3 (dd, 23, 3, PCH), 42.7 (d, 23, PCH),
10.3 (d, 26, PCH3)
others (Cy): 31.65 (s), 30.8 (d, 6), 29.9 (d, 6),
28.3-29.1 (m), 27.9 (d, 8), 27.1 (d, 11)
65.0 (d, 10) 129.7 (s, Cp),
128.9 (Co, under
solvent peak),
127.8 (d, 8, Cm)
e
5a‚NH3 129.1 (s) 124.9 (s) 109.7 (d, 4) -21.4 (av) 64.5 (s)
86.4 (s)
62.7 (d, 9) 133.8 (d, 19, Co),
131.2 (d, 1, Cp),
Ci (br, under Co),
HPCy2: 42.2 (dd, 30, 2, PCH),
36.6 (dd, 25, 2, PCH)
others: 34.4 (d, 9), 33.8 (d, 4), 31.6 (s),
28.2-28.0 (om), 27.7-27.5 (om), 26.3 (s)
128.3 (s) 123.9 (s) 109.0 (d, 4)
129.4 (d, 9, Cm)
6ad
123.7 (s) 122.5 (s) 109.2 (s)
122.8 (s) 121.9 (s) 107.0 (s)
-22.6 (av) 94.6 (s)
70.4 (d, 10) 163.6 (dd, 24,
63.8 (d, 10) 15, Co-Ru),
152.9 (d, 47, Ci),
140.5 (d, 19, Co),
140.0 (d, 36, Ci),
136.2 (d, 24, Ci),
others: 132.8 (d, 10),
132.6 (d, 11),
HPCy2: 36.8 (d, 23, PCH),
36.2 (dd, 25, 5, PCH)
others: 32.1-31.8 (m), 31.5 (s),
28.5 (d, 13), 28.2 (d, 10),
28.1 (d, 9), 28.0 (d, 11),
27.0 (d, 9)
129.4 (d, 3),
129.1 (s), 128.7 (s),
128.5-128.4 (m),
126.2 (s),
121.3 (d, 9)
8ac
124.7 (s) 123.3 (s) 116.3 (s)
122.3 (s) 120.9 (s) 113.3 (s)
-15.9 (av) 92.1 (s)
72.9 (d, 9) 133.9 (br s, 36, Ci), HPCy2: 43.9 (dd, 24, 4, PCH), 41.3 (d, 18, PCH)
63.3 (d,10) Co (br, in baseline), others: 39.7 (d, 8), 36.1 (d, 8), 29.8 (s), 28.9 (s),
128.6 (s, Cp),
127.3 (d, 9, Cm)
28.8 (d, 8), 28.2 (d, 11), 28.0 (d, 8),
27.2 (d, 11), 26.7 (s), 26.3 (s)
SiEt3: 12.5 (s, CH2), 11.4 (s, CH3)
9ad,f
9bd,f
123.8 (s) 122.7 (s) 110.7 (s)
123.2 (s) 122.6 (s) 108.9 (s)
-20.9 (av) 85.5 (s)
-21.1 (av) 85.2 (s)
72.2 (d, 11) 142.1 (d, 39, Ci),
66.5 (d, 9) 134.5 (d, 11, Co)
PdC(CH2)5(Cy): 37.1 (d, 16), 36.4 (d, 11),
34.78 (s), 32.7 (s), 30.6 (s), 29.8 (d, 13),
27.6 (d, 10), 26.56 (s)
PdC(CH3)2(iPr): 22.5 (s, dC(CH3)),
20.5 (s, dC(CH3))
124.0 (s) 122.7 (s) 110.7 (s)
123.3 (s) 122.6 (s) 108.5 (s)
72.1 (d, 9) 141.9 (d, 34, Ci),
66.6 (d, 9) 134.4 (d, 11, Co),
129.0 (s, Cp)
others: 31.3 (d, 9), 27.2 (d, 13), 25.2 (d, 10)
a δ values are given in ppm; in parentheses are given the multiplicity and JPC or ω1/2 values in Hz. om ) overlapping multiplets. See footnote a in Table
1 for the indenyl numbering scheme. b ∆δ(C3a,7a) ) δ(C3a,7a(η-indenyl complex)) - δ(C3a,7a(η-sodium indenyl)). δ(C3a,7a) for sodium indenyl is 130.7 ppm.22
c Sample in CDCl3. d Sample in C6D6. e Sample in CD2Cl2. f Due to the small abundance of complexes 9a (12%) and 9b (16%), not all of their 13C peaks
could be assigned.

1480 Organometallics, Vol. 26, No. 6, 2007
Derrah et al.
Table 3. Crystallographic Data
2a‚0.25(pentane)
40.25H47P2Ru
3a
[5a‚NH3]PF6
8a
formula
formula wt
C
C40H44OP2Ru
703.76
C39H48F6NP3Ru
838.76
C45H60P2RuSi
693.79
792.03
cryst growth conditions
slow evap from min
vol of pentane
min vol of toluene
with layered pentane
(1:8 vol ratio)
min vol of CH2Cl2 with
slow vapor diffusion
of diethyl ether
(1:5 vol ratio)
orange
min vol of toluene
with layered pentane
(1:10 vol ratio)
cryst color
purple
orange
yellow
cryst dimens (mm)
cryst syst, space group
0.46 × 0.18 × 0.13
monoclinic, P21/n
10.3907(13)
13.5621(16)
25.866(3)
0.55 × 0.18 × 0.09
triclinic, PI
9.8311(12)
12.3025(15)
15.6685(19)
97.7025(17)
101.4607(17)
110.8896(16)
1691.2(4)
0.64 × 0.17 × 0.16
triclinic, PI
9.1385(4)
10.8856(5)
20.1951(8)
100.9043(7)
92.2008(7)
107.7646(6)
1868.68(14)
2
0.42 × 0.23 × 0.17
triclinic, PI
11.5039(14)
12.0314(14)
16.4281(19)
81.4603(17)
89.8746(17)
64.4406(15)
2023.6(4)
a (Å)
b (Å)
c (Å)
R(deg)
â (deg)
γ (deg)
V (Å3)
Z
100.432(2)
3584.8(8)
4
1.285
2
2
F
calcd (g cm-3
)
1.382
0.589
1.491
0.608
1.300
0.526
µ (mm-1
)
0.553
total data collected
26 806 (-12 e h e 12,
-16 e k e 16,
-32 e l e 32)
7309 (Rint ) 0.0956)
4859
7309/0/379
0.981
0.0603
13 520 (-12 e h e 12,
-15 e k e 15,
-19 e l e 19)
6929 (Rint ) 0.0231)
6285
6929/0/397
1.137
0.0298
14 476 (-11 e h e 11,
-13 e k e 13,
-25 e l e 25)
7611 (Rint ) 0.0187)
6961
7611/0/456
1.091
0.0286
15 662 (-14 e h e 14,
-14 e k e 14,
-20 e l e 20)
8117 (Rint ) 0.0274)
6661
no. of indep rflns
no. of obsd rflns (Fo2 g 2σ(Fo ))
no. of data/restraints/params
goodness of fit (S)b
2
8117/3a/452
1.111
0.0315
0.0860
0.483, -0.463
2
R1 (Fo2 g 2σ (Fo ))c
wR2 (all data)d
0.1576
1.929, -1.062
0.0772
0.501, -0.299
0.0816
0.749, -0.434
largest diff peak, hole (e Å-3
)
a
Distances involving a disordered Si-Et group were constrained to be equal (within 0.001 Å) during refinement: d(Si-C65A) ) d(Si-C65B); d(Si‚‚‚C66A)
2
2
) d(Si‚‚‚C66A); d(C65A-C66A) ) d(C65B-C66B). b S ) [∑w(Fo - Fc )2/(n - p)]1/2 (n ) number of data; p ) number of parameters varied; w )
[σ2(Fo2) + (A0P)2+ A1P]-1. A values are as follows: for 2a, A0 ) 0.0891, A1 ) 0; for 3a, A0 ) 0.0235, A1 ) 1.6166; for [5a‚NH3]PF6, A0 ) 0.0467, A1
2
2
4
) 0.7394; for 8a, A0 ) 0.0439, A1 ) 0.2208. c R1) ∑||Fo| - |Fc||/∑|Fo|. d wR2) [∑w(Fo - Fc )2/∑w(Fo )]1/2
.
follows. 31P{1H} NMR (202.46 MHz, δ): 243.4 (d, JPP ) 36 Hz,
“PCy2”), 62.3 (d, PPh3). 1H NMR (500 MHz, δRu-H): -15.89 ppm.
Inert-atmosphere MALDI-TOF-MS of the 2a/9a mixture (pyrene
in benzene matrix; m/z (relative intensity)): 676.6 (100%) [M+],
479.6 (33%) [M+ - PCy2], 412.6 (10%) [M+ - PPh3].
Method B. This alternate method allows the synthesis of (slightly
less pure) 2a on a scale larger than that given above. To a Schlenk
flask containing a dark red solution/suspension of 1a (736 mg, 1.0
mmol) in toluene (20 mL) was added KOBut (134 mg, 1.2 mmol,
1.2 equiv). The resulting dark blue solution was stirred for 16 h
before the solvent was removed by evaporation to give a dark blue
oil. The product was redissolved in a 1:5 toluene/hexanes solution
(2 × 25 mL) and filtered through Celite to remove any solid
impurities. The solvent was removed under vacuum, and the green-
black powder was washed with cold pentane (3 × 10 mL, -30 °C),
resulting in a dark blue powder (545 mg, 0.81 mmol, 81% crude
yield).
(b) [Ru(PPri2)(η5-indenyl)(PPh3)] (2b). To a dark red solution/
suspension of 1b (75 mg, 0.12 mmol) in toluene (5 mL) was added
KOBut (16 mg, 0.14 mmol, 1.2 equiv). The resulting dark blue
solution was stirred for 2 h to ensure complete reaction, the solvent
was removed under vacuum, the resulting dark blue oil was
dissolved in pentane (5 mL), and this solution was filtered through
Celite to remove solid impurities. The solution was placed in the
freezer (-30 °C) for 3 days, and dark blue crystals (61 mg, 0.10
mmol, 83%) were isolated after filtration and 3 × 10 mL washings
with cold pentane (-30 °C). 1H NMR shows this product
(containing 2b and 9b in an 84:16 ratio) contains ∼0.5 equiv of
pentane but is otherwise clean. Its extreme air sensitivity, however,
has precluded elemental analysis.
in solutions of 2b/9b. Data for 6b are as follows. 31P{1H} NMR
(145.80 MHz, C6D6, δ): 66.5 (d, JPP ) 29 Hz, HPCy2), -20.8 (d,
PPh3).
(c) [Ru(PCy2)(η5-indenyl)(CO)(PPh3)] (3a). A Schlenk flask
containing a dark blue solution of 2a (160 mg, 0.24 mmol) in
toluene (2 mL) was placed under an atmosphere of CO. The
resulting dark red solution was stirred for 10 min before the solvent
was removed under vacuum. Addition of pentane (5 mL) to the
residue gave an orange-red suspension, which was filtered and
washed with cold pentane (3 × 5 mL) to give an orange-red powder
(120 mg, 0.17 mmol, 71% crude yield). Recrystallization from
toluene (5 mL) by slow diffusion of a layer of pentane (40 mL)
gave [Ru(PCy2)(η5-indenyl)(CO)(PPh3)] (3a) as a red crystalline
solid (54 mg, 0.08 mmol, 45% yield). 31P{1H} NMR (202.46 MHz,
2
C6D6, δ): 56.9 (d, JPP ) 8 Hz, PCy2), 52.2 (d, PPh3). IR (KBr,
cm-1); 1931 (s, νCO). FAB-MS (+LSIMS matrix mNBA; m/z
(relative intensity)): 705.2 (100%) [M+ + H], 479.0 (27%) [M+
- HPCy2 - CO]. HR-MS (+LSIMS matrix mNBA): exact mass
(monoisotopic) calcd for C40H44OP2Ru + H, 705.1989; found,
705.1983 ( 0.0035 (average of 3 trials). Anal. Calcd for C40H44-
OP2Ru: C, 68.26; H, 6.30. Found: C, 68.17; H, 6.55. Dec pt: 161-
163 °C.
(d) [Ru(PPh2)(η5-indenyl)(CO)(PPh3)] (3c). In a Schlenk flask
containing 1c (299 mg, 0.43 mmol), a dark red solution/suspension
was formed by addition of toluene (5 mL). The solution was
saturated with CO, and then KOBut (96 mg, 0.86 mmol, 2 equiv)
was added. The resulting dark red solution was stirred for 10 min,
and then solvent and excess CO were removed under vacuum to
give a purple solid. A solution of the residue in toluene (30 mL)
was filtered through Celite to remove solid impurities and then
concentrated to 5 mL under vacuum. Recrystallization by slow layer
diffusion of pentane (40 mL) at low temperature (-30 °C) gave
dark purple crystals of [Ru(PPh2)(η5-indenyl)(CO)(PPh3)] (3c; 241
mg, 0.35 mmol, 81%). 31P{1H} NMR (202.46 MHz, C6D6, δ): 51.7
Data for 2b are as follows. 31P{1H} NMR (202.46 MHz, C6D6,
δ): 288.3 (d, JPP ) 65 Hz, PiPr2), 63.2 (d, PPh3). Data for 9b are
as follows. 31P{1H} NMR (202.46 MHz, C6D6, δ): 256.4 (d, JPP
) 38 Hz, “PiPr2”), 63.2 (d, PPh3, overlapping with signal due to
2b). Over time, the ortho-metalated product 6b was also observed
2
(d, JPP ) 8 Hz, PPh3), 17.9 (d, PPh2). IR (KBr, cm-1); 1921 (s,

A Ruthenium-Phosphorus Double Bond
Organometallics, Vol. 26, No. 6, 2007 1481
ν
CO). FAB-MS (+LSIMS matrix mNBA; m/z (relative intensity)):
(h) [Ru(η5-indenyl)(SiEt3)(HPCy2)(PPh3)] (8a). To a solution
of 2a (81 mg, 0.12 mmol) in toluene (2 mL) was added HSiEt3
(14 mg, 0.12 mmol) in toluene (2 mL). With stirring, the dark blue
mixture slowly changed to golden yellow (12-16 h). The solvent
was removed under vacuum, and pentane (1 mL) was added to
give a yellow suspension, which was filtered and washed with cold
pentane (3 × 5 mL). Slow evaporation (-25 °C) of a toluene
solution (5 mL) of the resulting yellow powder (42 mg) gave
analytically pure 7a (29 mg, 0.037 mmol, 31%). 31P{1H} NMR
693.0 (100%) [M+ + H], 506.9 (17%) [M+ - HPPh2], 478.9 (58%)
[M+ - HPPh2 - CO], 401.9 (18%) [M+ - PPh3 - CO]. HR-MS
(+LSIMS matrix mNBA): exact mass (monoisotopic) calcd for
C40H32OP2Ru + H, 693.1050; found, 693.1071 ( 0.0038 (average
of 3 trials). Anal. Calcd for C40H32OP2Ru: C, 69.46; H, 4.66.
Found: C, 69.41; H, 4.68. Dec pt: 163-166 °C.
(e) [Ru(PTolp )(η5-indenyl)(CO)(PPh3)] (3d). In a Schlenk flask
2
containing 1d (254 mg, 0.35 mmol) a dark red solution/suspension
was formed by addition of toluene (5 mL). The solution was
saturated with CO, and then KOBut (78 mg, 0.70 mmol, 2 equiv)
was added. The resulting dark red solution was stirred for 10 min
before solvent and excess CO were removed under vacuum to give
a strawberry red solid. The product was redissolved in toluene (30
mL) and this solution filtered through Celite to remove solid
impurities. The solution was reduced to 2 mL under vacuum and
recrystallized by slow layer diffusion of pentane (50 mL) at low
2
(202.46 MHz, CDCl3, δ): 55.3 (d, JPP ) 28 Hz, PPh3), 47.5 (d,
HPCy2). IR (KBr, cm-1): 2307 (w, νP-H). Anal. Calcd for C45H60-
SiP2Ru: C, 68.24; H, 7.63. Found: C, 68.12; H, 7.38. Dec pt: 161-
164 °C.
NMR Scale Reactions of 2a.
(a) Reaction with [HNEt3][Cl]. Solid 2a (30 mg, 0.044 mmol)
and [HNEt3][Cl] (6 mg, 0.04 mmol) were placed in a sealable NMR
tube. CD2Cl2 (0.8 mL) was transferred under vacuum, and the tube
was flame-sealed. The thawed solution was shaken to mix the
reagents before being placed in the NMR spectrometer, where the
disappearance of 2a and appearance of 1a was monitored by 31P-
{1H} NMR spectroscopy. Complete consumption of 2a occurred
within 30 min at room temperature, giving ∼90% of 1a.
(b) Reaction with HCl. Solid 2a (31 mg, 0.046 mmol) was
placed in a sealable NMR tube, and C6D6 (0.8 mL) was transferred
under vacuum. Ethereal HCl (2 M, 28 µL, 0.057 mmol) was added,
and the tube was flame-sealed. The thawed solution was shaken
for 5 min to mix the reagents before being placed in the NMR
spectrometer; however, the blue color of the solution did not
immediately disappear. The slow consumption of 2a may be due
to the low solubility of HCl in benzene. After 20 min the mixture
contained compound 1a (32%) along with 2a, 9a, and other
unidentified products. After 2 days, the sample was yellow-orange
and contained 1a as the major product (66%).
temperature (-30 °C) to give [Ru(PTolp )(η5-indenyl)(CO)(PPh3)]
2
(3d) as a red crystalline solid (175 mg, 0.24 mmol, 69%). 31P{1H}
2
NMR (202.46 MHz, C6D6, δ): 51.8 (d, JPP ) 7 Hz, PPh3), 17.3
(d, PTolp ). IR (KBr, cm-1): 1926 (s, νCO). FAB-MS (+LSIMS
2
matrix mNBA; m/z (relative intensity)): 721.1 (100%) [M+ + H],
478.9 (65%) [M+ - HPTolp2 - CO], 430.9 (21%) [M+ - PPh3 -
CO]. HR-MS (+LSIMS matrix mNBA): exact mass (monoisotopic)
calcd for C42H36OP2Ru + H, 721.1363; found, 721.1361 ( 0.0031
(average of 3 trials). Anal. Calcd for C42H36OP2Ru: C, 70.09; H,
5.04. Found: C, 69.21; H, 4.93. Dec pt: 155-156 °C. (We note
that the crude product is consistently accompanied by a small
amount (e5%) of [Ru(PTolp )(η5-indenyl)(CO)2], resulting from
2
substitution of PPh3 (31P{1H} NMR (202.46 MHz, C6D6, δ): 63.8
(s, PTolp )), even with very short reaction times.)
2
(f) [Ru(η5-indenyl)I(PMeCy2)(PPh3)] (4a). To a Schlenk flask
containing a dark blue solution of 2a (220 mg, 0.32 mmol) in
toluene (2 mL) was added MeI (0.10 mL, 1.6 mmol, excess). The
reaction mixture was stirred for 1 h, to give a dark red solution.
The solvent was removed under vacuum, and pentane (5 mL) was
added to give a red-brown suspension, which was filtered and
washed with cold pentane (3 × 5 mL) to give [Ru(η5-indenyl)I-
(PMeCy2)(PPh3)] (4a; 197 mg, 0.24 mmol, 75% crude yield). A
crude sample (102 mg, 0.12 mmol) was recrystallized from benzene
(5 mL) by slow vapor diffusion of hexanes to give analytically
pure 4a (82 mg, 0.10 mmol, 80%). 31P{1H} NMR (202.46 MHz,
CDCl3, δ): 49.5 (d, JPP ) 37 Hz, PPh3), 39.2 (d, PMeCy2). FAB-
MS (+LSIMS matrix mNBA; m/z (relative intensity)): 818.1 (36%)
[M+], 691.2 (89%) [M+ - I], 605.9 (18%) [M+ - MePCy2], 556.0
(100%) [M+ - PPh3], 478.9 (68%) [M+ - I - MePCy2], 344.9
(73%) [M+ - PPh3 - MePCy2]. HR-MS (+LSIMS matrix
mNBA): calcd for C40H47IP2Ru, 818.1241; found, 818.1255 (
0.0018 (average of 3 trials). Anal. Calcd for C40H47IP2Ru: C, 58.75;
H, 5.79. Found: C, 58.63; H, 5.66. Dec pt: 115-116 °C.
(c) Thermal Decomposition. Solid 2a (25 mg, 0.037 mmol)
and triphenylphosphine oxide (13.1 mg, 0.047 mmol, internal
standard) were placed in a sealable NMR tube. C7D8 (0.8 mL) was
transferred under vacuum, and the tube was flame-sealed. The
progress of the reaction was monitored at 77 °C (probe temperature)
by 31P{1H} NMR. Complete consumption of 2a (5.5 h) gave mainly
[Ru(η5-indenyl){κ2-(o-C6H4)PPh2}(HPCy2)] (6a; 89%).
Data for 6a are as follows. 31P{1H} NMR (202.46 MHz, δ): 57.2
(d, JPP ) 28 Hz, HPCy2), -20.0 (d, PPh3).
(d) Reaction with H2(g). Solid 2a (25 mg, 0.037 mmol) and
triphenylphosphine oxide (10.4 mg, 0.037 mmol, internal standard)
were placed in a sealable NMR tube. C6D6 (0.8 mL) was transferred
under vacuum, and slightly less than 1 atm of hydrogen gas was
introduced before the tube was flame-sealed. The thawed solution
was shaken until the dark blue solution turned yellow (5 min). 31P-
{1H} NMR showed the conversion of 2a to [Ru(η5-indenyl)(H)-
(HPCy2)(PPh3)] (7a) (98%).
(g) [Ru(η5-indenyl)(NH3)(HPCy2)(PPh3)]PF6 ([5a‚NH3]PF6).
To a solution of 2a (97 mg, 0.14 mmol) in toluene (3 mL) was
added [NH4][PF6] (23 mg, 0.14 mmol). With stirring, the blue
solution slowly (12-16 h) changed to a yellow suspension, which
was filtered and washed with hexanes (3 × 5 mL) to give a bright
yellow powder (108 mg). Recrystallization from CH2Cl2 (2 mL)
by the slow vapor diffusion of ether (10 mL) gave analytically pure
[5a‚NH3](PF6) (69 mg, 0.082 mmol, 60%). 31P{1H} NMR (202.46
MHz, CD2Cl2, δ): 59.4 (d, 2JPP ) 38 Hz, HPCy2), 55.0 (d, PPh3),
Other NMR Scale Reactions.
(a) Monitoring the Formation of [Ru(PPh2)(η5-indenyl)-
(PPh3)] (2c). Toluene-d8 (0.8 mL) was transferred under vacuum
to a sealable NMR tube containing solid 1c (26 mg, 0.037 mmol)
and KOBut (5 mg, 0.044 mmol, 1.2 equiv), frozen in N2(l). The
tube was flame-sealed and placed in an acetone/dry ice bath to thaw.
The sample was then placed in the 360 MHz NMR spectrometer
precooled to 230 K, and the progress of the reaction was monitored
by 31P{1H} NMR spectroscopy as the temperature was increased
in 5 K intervals. At 245 K a small amount of [Ru(PPh2)(η5-indenyl)-
(PPh3)] (2c; ∼25%) was observed, but no further change occurred
as the temperature was increased to 260 K. The sample (a green
solution) was removed, quickly shaken, and then placed back in
the spectrometer. The main product was still unreacted 1c (∼40%)
with an unchanged amount of 2c (∼25%) and other, unidentified
products (∼35%). The sample was then removed from the
spectrometer and warmed. When it reached room temperature, the
-144.0 (sept, JPF ) 710 Hz, PF6-). IR (KBr, cm-1): 3354 (w,
1
ν
N-H), 2342 (w, νP-H). FAB-MS (+LSIMS matrix mNBA; m/z
(relative intensity)): 694.2 (13%) [M+], 677.2 (100%) [M+ - NH3],
479.0 (31%) [M+ - NH3 - HPCy2], 413 (15%) [M+ - NH3 -
PPh3 - H+]. HR-MS (+LSIMS matrix mNBA): calcd for C39H48-
NP2Ru, 694.2306; found, 694.2307 ( 0.0007 (average of 3 trials).
Anal. Calcd for C39H48F6NP3Ru: C, 55.85; H, 5.77. Found: C,
55.56; H, 5.62. Dec pt: 169-171 °C.

1482 Organometallics, Vol. 26, No. 6, 2007
Derrah et al.
dark green solution spontaneously turned black, giving a complex
mixture of unidentified products.
Computational Details. Geometry optimization and time-
dependent (TD-DFT) calculations were performed with the hybrid
PBE1PBE density functional, which incorporates 25% of exact
exchange.25 The relativistic effective core potential of the Stuttgart
group (ECP28MWB) along with the associated valence basis set
were used for ruthenium.26 In the calculations of the simplified
models of 2/9 and their interconversion the 6-31++G(d,p) basis
sets were used for P, C, and H, whereas calculations on 2a with
the full ligand system employed the 6-31G(d) basis sets for
phosphorus and the indenyl carbons and the STO-3G basis sets for
the remaining atomic centers. All calculations were performed with
Gaussian03,27 and the TD-DFT results were analyzed with the
SWizard program.28 Ellipticity values were determined from
analysis of the electron density with XAim.29
Data for 2c in C7D8 at 250 K are as follows. 31P{1H} NMR
(145.80 MHz, δ): 195.8 (d, JPP ) 63 Hz, PPh2), 58.2 (d, PPh3).
(b) Monitoring the Formation of [Ru(PTolp )(η5-indenyl)-
2
(PPh3)] (2d). Toluene-d8 (0.8 mL) was transferred under vacuum
to a sealable NMR tube containing solid 1d (28 mg, 0.038 mmol)
and KOBut (5 mg, 0.046 mmol, 1.2 equiv), frozen in N2(l). The
tube was flame-sealed and placed in an acetone/dry ice bath to thaw.
The sample was then placed in the 360 MHz NMR spectrometer
precooled to 190 K. The progress of the reaction was monitored
by 31P{1H} NMR spectroscopy as the temperature was increased
in 5 K intervals. At 250 K a small singlet appeared at 66.2 ppm.
No new product formation was observed as the temperature was
increased to 260 K. The sample was removed from the spectrometer,
shaken quickly, resulting in a green solution, and then placed back
in the spectrometer. The main product was still the unknown
complex at 66.2 ppm (∼40%), but [Ru(P(Tolp)2)(η5-indenyl)(PPh3)]
(2d, ∼36%) and other unidentified products (∼24%) were also
observed. At room temperature the green color of this mixture
persisted for ∼1 h, before decomposing to a black mixture of
unidentified products.
Acknowledgment. We thank the NSERC of Canada for
financial support, Prof. John E. McGrady (University of
Glasgow) for helpful discussions, Prof. Deryn E. Fogg and
Johanna M. Blacquiere (University of Ottawa) for inert-
atmosphere MALDI-TOF analysis, and Shaun A. Hall (Uni-
versity of Victoria) for the preparation of complex 1d.
Data for 2d in C7D8 at 260 K are as follows. 31P{1H} NMR
Supporting Information Available: Tables giving DFT opti-
mized coordinates and calculated energies and CIF files giving
crystallographic data. This material is available free of charge via
the Internet at http://pubs.acs.org.
(145.80 MHz, δ): 201.7 (d, JPP ) 63 Hz, PTolp ), 60.6 (d, PPh3).
2
Crystallographic Study of 2a. Attempts to refine peaks of
residual electron density as solvent n-pentane carbon atoms in
crystals of 2a were unsuccessful. The data were corrected for
disordered electron density through use of the SQUEEZE proce-
dure23 as implemented in PLATON.24 A total solvent-accessible
void volume of 521.7 Å3 with a total electron count of 91 (consistent
with one molecule of solvent n-pentane) was found in the unit cell.
OM0700056
(25) Perdew, J. P.; Burke, K.; Ernzerhof, M. Phys. ReV. Lett. 1996, 77,
3865.
(26) Andrae, D.; Haussermann, U.; Dolg, M.; Stoll, H.; Preuss, H. Theor.
Chim. Acta 1990, 77, 123.
(22) Gamasa, M. P.; Gimeno, J.; Gonzalez-Bernardo, C.; Martin-Vaca,
B. M. Organometallics 1996, 15, 302.
(23) van der Sluis, P.; Spek, A. L. Acta Crystallogr. 1990, A46, 194.
(24) Spek, A. L. Acta Crystallogr. 1990, A46, C34 (PLATON-A Multi-
purpose Crystallographic Tool; Utrecht University, Utrecht, The Netherlands).
(27) Frisch, M. J., et al. Gaussian 03 (Revision B.03); see the Supporting
Information.
(28) Gorelsky, S. I. SWizard program; http://www.sg-chem.net.
(29) Ortiz Alba, J. C.; Bo, C. Xaim-1.0; Universitat Rovira i Virgili,
Tarragona, Spain.