(p-cymene) ruthenium (II) (diphenylphosphino) alkyne complexes: Preparation of (μ-Cl) (μ-PPh2C≡CR)-bridged Ru/Pt heterobimetallic complexes

Article abstract of DOI:10.1021/om049676j

The neutral complexes [n⁶-p-cymene)RuCl₂(PPh ₂C≡CR)] (R = Ph 1, ^tBu 2, (4-CH₃)C ₆H₄ 3, (4-C≡CPh)C₆H₄ 4, (4-CN)C₆H₄ 5) have been synthesized by reacting [(p-cymene)RuCl₂]₂ with the respective alkynylphosphine. Treatment of 1-5 with AgOTf or T1PF₆ and the corresponding PPh ₂C≡CR allows the preparation of cationic bis(diphenylphosphino) compounds [(n⁶-p-cymene)RuCl(PPh₂C=CR)₂]X (X = OTf; R = Ph 6, ^tBu 7, (4-CH₃)C₆H₄ 8, (4-C≡CPh)C₆H₄ 9, X = PF₆; R = (4-CN)C₆H₄10). All complexes have been characterized by analytical and spectroscopic methods, by cyclic voltammetry, and in several cases (3 and 7) by X-ray crystallography. Reactions of both neutral (1-4) and cationic (6-8) complexes with [cis-Pt(C₆F₅) ₂(thf)₂] (thf = tetrahydrofuran) gave heterobimetallic neutral [(n⁶-p-cymene)Cl-Ru(μ-Cl)(μ-1KP:n²-PPh ₂C=CR)Pt(C₆F₅)₂] (R = Ph 11a, ^tBu 12a, (4-CH₃)C₆H₄13a, (4-C≡CPh)-C₆H₄ 14a) and cationic [(n ⁶-p-cymene)(PPh₂C≡CR)Ru(μ-Cl)(μ-1K:P:n ²-PPh₂C≡CR)Pt(C₆F₅) ₂]-(OTf) (R = Ph 15, ^tBu 16, (4-CH₃)C ₆H₄ 17) derivatives stabilized by a mixed Cl/PPh ₂C≡CR bridging system. The molecular structures of 12a and 17 have been confirmed by X-ray diffraction. However, the neutral complexes 11-14 existed in solution as a mixture of isomers [(n ⁶-p-cymene)ClRu(μ-Cl)(μ-1kP:n²-PPh ₂C≡CR)Pt(C₆F₅)₂] (a) and [(n⁶-p-cymene)(PPh₂C≡CR)Ru-(μ-Cl) ₂Pt(C₆F₅)₂] (b), respectively.

Full text of DOI:10.1021/om049676j

4288
Organometallics 2004, 23, 4288-4300
(p-cym en e)Ru th en iu m (II)(d ip h en ylp h osp h in o)a lk yn e
Com p lexes: P r ep a r a tion of (µ-Cl)(µ-P P h 2CtCR)-Br id ged
Ru /P t Heter obim eta llic Com p lexes
J esu´s R. Berenguer,† Mar´ıa Bernechea,† J uan Fornie´s,*,‡ Ana Garc´ıa,† and
Elena Lalinde*,†
Departamento de Qu´ımica, Grupo de Sı´ntesis Quı´mica de La Rioja, UA-CSIC,
Universidad de La Rioja, 26006, Logron˜o, Spain, and Departamento de Qu´ımica Inorga´nica,
Instituto de Ciencia de Materiales de Arago´n, Universidad de Zaragoza-Consejo Superior de
Investigaciones Cient´ıficas, 50009 Zaragoza, Spain
Received May 6, 2004
t
The neutral complexes [(η6-p-cymene)RuCl2(PPh2CtCR)] (R ) Ph 1, Bu 2, (4-CH3)C6H4
3, (4-CtCPh)C6H4 4, (4-CN)C6H4 5) have been synthesized by reacting [(p-cymene)RuCl2]2
with the respective alkynylphosphine. Treatment of 1-5 with AgOTf or TlPF6 and the
corresponding PPh2CtCR allows the preparation of cationic bis(diphenylphosphino)
t
compounds [(η6-p-cymene)RuCl(PPh2CtCR)2]X (X ) OTf; R ) Ph 6, Bu 7, (4-CH3)C6H4 8,
(4-CtCPh)C6H4 9, X ) PF6; R ) (4-CN)C6H4 10). All complexes have been characterized by
analytical and spectroscopic methods, by cyclic voltammetry, and in several cases (3 and 7)
by X-ray crystallography. Reactions of both neutral (1-4) and cationic (6-8) complexes with
[cis-Pt(C6F5)2(thf)2] (thf ) tetrahydrofuran) gave heterobimetallic neutral [(η6-p-cymene)Cl-
Ru(µ-Cl)(µ-1κP:η2-PPh2CtCR)Pt(C6F5)2] (R ) Ph 11a , tBu 12a , (4-CH3)C6H4 13a , (4-CtCPh)-
C6H4 14a ) and cationic [(η6-p-cymene)(PPh2CtCR)Ru(µ-Cl)(µ-1κP:η2-PPh2CtCR)Pt(C6F5)2]-
t
(OTf) (R ) Ph 15, Bu 16, (4-CH3)C6H4 17) derivatives stabilized by a mixed Cl/PPh2CtCR
bridging system. The molecular structures of 12a and 17 have been confirmed by X-ray
diffraction. However, the neutral complexes 11-14 existed in solution as a mixture of isomers
[(η6-p-cymene)ClRu(µ-Cl)(µ-1κP:η2-PPh2CtCR)Pt(C6F5)2] (a) and [(η6-p-cymene)(PPh2CtCR)Ru-
(µ-Cl)2Pt(C6F5)2] (b), respectively.
In tr od u ction
functional phospines bearing a hard (N, O) donor atom,
since these ligands show interesting hemilabile prop-
erties.10-16 In contrast, the chemistry of analogous
(arene)ruthenium(II) complexes containing unsaturated
phosphines is relatively unexplored. Recently, Nelson
and co-workers have reported (arene)Ru(II) derivatives
with vinyl and allyl phosphines and 3,4-dimethyl-1-
phenylphosphole, showing interesting reactivity with
some of them.17,18 Thus, they found that complexes (η6-
arene)RuCl2(DPVP)] (DPVP ) diphenylvinylphosphine)
undergo a novel KOtBu-promoted hydroalkylation to
produce tethered phosphinopropylarene-ruthenium(II)
compounds.19 As far as we are aware, no analogous
derivatives have been reported with phosphinoalkynes,
The chemistry of half-sandwich η6-arene-ruthenium
complexes has been widely developed in the past decade,
in part due to their catalytic potential, but also due to
their usefulness in the synthesis of other Ru(0) and
Ru(II) complexes.1-3 In particular, (arene)ruthenium-
(II) complexes of the type [(η6-arene)RuCl2(PR3)] con-
taining aryl or alkyl phosphine as ancillary ligands have
been extensively studied, owing to their role as effective
precursors for a variety of catalytic and stoichiometric
organic transformations.2,4-9 Special interest is also
currently devoted to complexes stabilized by heterobi-
* Corresponding authors. E-mail: elena.lalinde@dq.unirioja.es;
forniesj@posta.unizar.es.
(10) Geldbach, T. J .; Pregosin, P. S. Eur. J . Inorg. Chem. 2002, 1907.
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Soc., Dalton Trans. 1999, 589.
† Universidad de La Rioja, UA-CSIC.
‡ Universidad de Zaragoza-CSIC.
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Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W.,
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Chem. 1989, 29, 163.
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10.1021/om049676j CCC: $27.50 © 2004 American Chemical Society
Publication on Web 08/06/2004

Ru/ Pt Heterobimetallic Complexes
Organometallics, Vol. 23, No. 18, 2004 4289
although these ligands (PPh2CtCR) have revealed an
interesting reactivity in transition metal chemistry,
such as P-C bond cleavages,20-26 insertion,27-32 and
coupling reactions.33,34 In addition, simple P-complex-
ation of these (Ph2PCRtCâ-R) ligands usually induces
a polarization35,36 in the alkyne function, with the CR
being partially negatively charged, making them sus-
ceptible to electrophilic and nucleophilic reactions with
simple molecules such as water,37,38 ethanol,39,40 XH,41
PPh2H,42 or amines.29,32
the nature of the M(M ) Rh, Ir)-P bond.48 As a
continuation of our work, we describe in this paper the
preparation, characterization, and electrochemical prop-
erties of novel neutral [(p-cymene)RuCl2(PPh2CtCR)]
and cationic [(p-cymene)RuCl(PPh2CtCR)2]+ arene com-
plexes, stabilized by different alkynylphosphines. The
reactivity of these complexes toward [cis-Pt(C6F5)2(thf)2]
has been investigated, to gain more insight into the
influence of both the Ru-P bonds and the nature of the
alkynyl substituent in the bonding capability of the
alkynyl fragment.
In previous papers, when studying the reactivity of
[cis-MX2(PPh2CtCR)2] (M ) Pd, Pt; X ) Cl,43 C6F5,44,45
t
t
or CtCR′;46 R ) Ph, Tol, Bu; R′ ) Ph, Bu) toward the
“cis-Pt(C6F5)2” synthon, we have shown an unprec-
edented and easy chemo-, regio-, and stereoselective
insertion of both PPh2CtCR ligands (R ) Ph, Tol) into
the robust Pt-C6F5 bond44,45 and also the very low η2-
bonding capability of the bulkier PPh2CtCtBu lig-
and.43,46,47 Moreover, we have also found that in the
iridium species [Cp*IrCl2(PPh2CtCPh)] the phenyl-
ethynyl fragment exhibits a stronger η2-bonding capa-
bility toward Pt(II) than the analogous rhodium deriva-
tive, which is a fact that can be mainly attributed to
Resu lts a n d Discu ssion
(i) Syn th esis of Mon on u clea r Com p lexes. The
novel alkynylphosphines PPh2CtC-(4-CtCPh)C6H4
and PPh2CtC-(4-CN)C6H4, as well as the previously
50
reported PPh2CtCR (R ) Ph,49 tBu,49 (4-CH3)C6H4
)
used in this work, have been prepared according to the
reported procedure by reaction of chlorodiphenylphos-
phine with the corresponding lithium acetylide.
The reaction of [{(η6-p-cymene)Ru(µ-Cl)Cl}2]51 with 2
molar equiv of alkynylphosphines PPh2CtCR (Scheme
1, i) in acetone, at room temperature, affords the
corresponding mononuclear complexes [(η6-p-cymene)-
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t
RuCl2(PPh2CtCR)] (R ) Ph 1, Bu 2, (4-CH3)C6H4 3,
(4-CtCPh)C6H4 4, (4-CN)C6H4 5), which are isolated as
air- and moisture-stable orange solids, in moderate
(61%) to high (84-94%) yield. As shown in Scheme 1
(path ii), a series of cationic derivatives containing two
P-coordinated alkynylphosphines [(η6-p-cymene)RuCl-
t
(PPh2CtCR)2]X (X ) OTf; R ) Ph 6, Bu 7, (4-CH3)-
C6H4 8, (4-CtCPh)C6H4 9, X ) PF6; R ) (4-CN)C6H4
10) were prepared by removing one of the chlorine
ligands in the neutral complexes (1-5) with silver
triflate (1-4) or TlPF6 (5) in acetone, followed by
subsequent treatment with 1 molar equiv of additional
PPh2CtCR. The products were isolated (53-97% yield)
by the usual workup (see Experimental Section) as air-
stable yellow (6-9) or orange (1-5, 10) solids and
characterized by means of standard analytic and spec-
troscopic techniques (see Experimental Section for
details), and in the case of complexes [(η6-p-cymene)-
RuCl2{PPh2CtC(4-CH3)C6H4}] (3) and [(η6-p-cymene)-
RuCl(PPh2CtCtBu)2](OTf) (7), their molecular struc-
tures have been confirmed by X-ray crystallography.
The IR spectra show a strong or medium (2, 4) ν(CtC)
band in the 2165-2176 cm-1 range, confirming the
P-coordination mode of the PPh2CtCR ligands49,50 and,
in the case of cationic derivatives, the characteristic
-
-
absorptions of CF3SO3 or PF6 (10) anions in the
expected regions (see Experimental Section). In all
complexes the corresponding phosphorus resonance
appears downfield shifted with respect to that of the free
PPh2CtCR. As has been previously noted,18,52 the
chemical shift ∆δ31P is generally greater by 2.15-8.51
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Chem. 1977, 16, 172.
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J . J . Chem. Soc., Dalton Trans. 1995, 1333.
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M. T.; Orpen, A. G.; Solano, S. Angew. Chem., Int. Ed. 1999, 38, 3058.
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M. T. Chem. Eur. J . 2002, 8, 3698.
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E. Organometallics 2002, 21, 2314.
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J . Can. J . Chem. 1971, 49, 2706.
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1991, 421, 335.
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2002, 648, 27.

4290 Organometallics, Vol. 23, No. 18, 2004
Berenguer et al.
Sch em e 1
Ta ble 1. Cr ysta llogr a p h ic Da ta for 3, 7, 12a ‚(CH3)2CO, a n d 17‚2CHCl3
3
7
12a ‚(CH3)2CO
17‚2CHCl3
empirical formula
fw
C31H31Cl2PRu
606.50
C47H52ClF3O3P2RuS
952.41
C43H39Cl2F10OPPtRu
1159.77
C67H50Cl7F13O3P2PtRuS
1788.38
temperature (K)
cryst syst
space group
a (Å)
b (Å)
c (Å)
173(1)
triclinic
P1h
223(1)
orthorhombic
Pc21n
15.5177(2)
16.8310(3)
17.4242(3)
90
173(1)
orthorhombic
P212121
12.9120(2)
14.1900(2)
23.1560(5)
90
223(1)
triclinic
P1h
9.3190(2)
11.7550(2)
12.9270(3)
94.2310(10)
100.5360(10)
99.1860(10)
1366.60(5)
2
12.3570(1)
14.3450(2)
19.7060(3)
90.2420(10)
91.8630(10)
103.8720(10)
3389.17(8)
2
R (deg)
â (deg)
90
90
90
90
γ (deg)
volume (Å3)
Z
4550.82(13)
4
1.390
0.571
1968
4242.67(13)
4
1.816
3.891
2264
Dcalcd (Mg/m3)
1.474
0.846
620
1.752
2.721
1760
abs coeff (mm-1
F(000)
)
cryst size (mm)
0.40 × 0.30 × 0.15
1.61 to 27.97
6485/0/320
1.027
0.40 × 0.30 × 0.30
4.11 to 27.56
10100/7/533
1.031
0.30 × 0.25 × 0.12
3.00 to 25.68
7949/4/540
1.031
0.35 × 0.25 × 0.25
4.14 to 27.88
15974/18/897
1.035
θ range for data collection (deg)
no. of data/restraints/params
goodness-of-fit on F2
final R indices [I > 2σ(I)]
R1 ) 0.0320,
wR2 ) 0.0709
R1 ) 0.0457,
wR2 ) 0.0752
0.576 and -0.716
R1 ) 0.0448,
wR2 ) 0.1034
R1 ) 0.0694,
wR2 ) 0.1137
0.599 and -0.806
R1 ) 0.0371,
wR2 ) 0.0757
R1 ) 0.0468,
wR2 ) 0.0788
1.575 and -0.846
R1 ) 0.0434,
wR2 ) 0.0970
R1 ) 0.0687,
wR2 ) 0.1071
0.909 and -1.297
R indices (all data)
largest diff peak and hole (e‚Å-3
)
ppm for the cationic [(η6-p-cymene)RuCl(PPh2CtCR)2]X
(6-10) complexes (∆δ 36.79-40.22 ppm) than for the
neutral (1-5) derivatives (∆δ 30.30-34.64 ppm). It is
remarkable that for the neutral complexes the observed
∆δP increases (2 < 3 < 1 < 4 < 5) as the acceptor
properties of the CtCR ligands increase (R ) tBu < (4-
CH3)C6H4< Ph < (4-CtCPh)C6H4 < (4-CN)C6H4). When
the uncoordinated P-CR and Câ alkyne carbon reso-
nances35,36,47,48 are compared with those of the free
phosphines, several trends are clearly observed: Upon
coordination, the CR resonances (doublet in 1-5, or A
part of an AXX′ spin system in 6-9) shift upfield, this
shift, ∆δ (ppm), being particularly significant in the
cationic derivatives (∆δ 1.6-3.7 ppm for 1-5 vs 4.8-
9.8 ppm for 6-9). On the other hand, and in accordance
with previous observations,48 in Rh and Ir(III) deriva-
tives, the Câ signals are only slightly affected in the
neutral complexes (1-5), but clearly move downfield for
the cationic ones (∆ 3.8 6, 3.3 7, 6.0 8, 5.3 9 ppm). As a
consequence, the final chemical shift differences (δCâ-
δCR), which are related to the polarization of the CtC
triple bond, are notably higher in the cationic bis-
(phosphine)ruthenium complexes than in the neutral
[(η6-p-cymene)RuCl2(PPh2CtCR)] derivatives. Interest-
ingly, we had previously observed that complexation of
two PPh2CtCPh molecules to the neutral “Ru(η5-C5-
Me5)Cl” fragment does not have an effect on the alkyne
polarization.48 The steric constraint around the metal
center in the cationic 6-9 derivatives containing two
PPh2CtCR ligands is clearly reflected in the 13C signals
due to the phenyl rings bonded to phosphorus, which
are chemical shift inequivalent, thus suggesting that the
rotation across the Ru-P bond is hindered or at least
slow on the NMR time scale.
X-ray crystallographic analyses confirm the structures
of 3 and 7 (Table 1 and Figure 1). Both the neutral
derivative 1 and the cation 7+ exhibit the expected and
usual pseudo-octahedral half-sandwich disposition around
the Ru atom, with the p-cymene ligand occupying one
face of the octahedron. The Ru-Cl distance, slightly

Ru/ Pt Heterobimetallic Complexes
Organometallics, Vol. 23, No. 18, 2004 4291
has been previously observed for related [(arene)(PR3)-
RuIIL2] complexes.53,54
The uncoordinated alkynyl fragments in the phos-
phine ligands in both species display a virtually linear
geometry, with typical CtC bond distances (1.187(6)-
1.198(3) Å). It should be mentioned that the two
acetylene units in the cation 7+ do not exhibit the
eclipsed arrangement previously found in [Cp*MCl-
(PPh2CtCPh)2]+ (M ) Rh, Ir) and [Cp*RuCl(PPh2Ct
CPh)2],48 containing the diphenyl(phenylethynyl)phos-
phine. As is observed in Figure 1b, in the cation [(η6-
p-cymene)RuCl(PPh2CtCtBu)2]+ and, probably, because
of the presence of two P-bonded bulkier tert-butylalkyn-
ylphosphines, the torsion angle CR-P-P-CR is 119.7°.
The electrochemistry of the complexes was investi-
gated by cyclic voltammetry (see Experimental Section
for details). For the neutral complexes 1-5, chemically
reversible one-electron Ru(II)/Ru(III) oxidations were
observed with potentials ranging from 0.69 to 0.74 V,
following correlation 2 < 3 < 1 < 4 < 5 identical to that
observed with ∆δ31P, i.e., ∆δ31P increases as E1/2
increases. Probably, due to their cationic nature, com-
plexes 9 and 10 do not give electrochemical response
between the CH2Cl2 windows. However, complexes 6-8
show no response from 0 to 1.8 V, but they unexpectedly
exhibit an irreversible reduction wave between -1.590
and -1.685 V, followed of a small oxidation feature
between -1.022 and -1.111 V in the reverse scan (all
values vs Fe+/Fe).
(ii) Syn th esis of Heter obin u clea r Com p lexes.
During the past decades important efforts have been
made to synthesize structurally defined polynuclear
complexes, in particular, heterobinuclear complexes,
mainly due to their potential application in catalysis.55-58
We have previously shown that [cis-Pt(C6F5)2(thf)2]
(thf ) tetrahydrofurane), having two weakly coordinat-
ing tetrahydrofurane molecules, is an excellent precur-
sor to homo- and heterobimetallic systems containing
the cis-Pt(C6F5)2 moiety.43,46-48,59-62 To examine the
bonding capability of the alkynyl fragments in the
neutral (1-5) and cationic (6-10) ruthenium(alky-
nylphosphine κ-P) complexes, the study of their reactiv-
ity toward [cis-Pt(C6F5)2(thf)2] was undertaken. The
results of this study are shown in Scheme 2.
At room temperature, the neutral compounds 1-4
react with [cis-Pt(C6F5)2(thf)2] in CH2Cl2 to yield
[(η6-p-cym en e)ClRu (µ-Cl)(µ-1κP :η2-P P h 2CtCR)P t -
(C6F5)2] (11a -14a ) as red (11a , 13a ), salmon pink (12a ),
or brown (14a ) solids. It should be noted that the
analogous reaction between [(η6-p-cymene)RuCl2{PPh2Ct
C(4-CN)C6H4}] (5) and [cis-Pt(C6F5)2(thf)2] yields only
a complex mixture of products, from which no pure
compound could be separated. Although two isomers are
possible, the IR spectra and the examination of several
crystals of 12a by X-ray spectroscopy revealed the
presence of only one isomer in the solid state, the one
stabilized by a mixed (µ-Cl)(µ-κP:η2-PPh2CtCR) bridg-
ing system. Complexes 11a -14a have been fully char-
F igu r e 1. Molecular structure of (a) [(η6-p-cymene)RuCl2-
PPh2CtC(4-CH3)C6H4}], 3, and (b) the cation [(η6-p-cymene)-
RuCl(PPh2CtCtBu)2]+ in 7. Selected bond lengths (Å) and
angles (deg): 3: Ru-P 2.3289(6), Ru-Cl 2.4024(6), 2.4109-
(6), P-CR 1.760(2), CR-Câ 1.198(3), P-Ru-Cl 84.73(2),
86.97(2), Cl-Ru-Cl 88.37(2), P-CR-Câ 173.0(2), CR-Câ-
Cγ 174.7(2); 7: Ru-P 2.3278(12), 2.3451(11), Ru-Cl 2.3849-
(11), P-CR 1.748(5), 1.745(5) CR-Câ 1.196(6), 1.187(6),
P-Ru-Cl 85.96(4), 88.89(4), P-Ru-P 91.64(4), P-CR-Câ
172.9(4), 171.7(4), CR-Câ-Cγ 176.2(5), 176.7(5).
shorter in 7+ (2.3849(11) Å) than those observed in 3
(2.4024(6), 2.4109(6) Å), Ru-P lengths (2.3289(6) Å 3;
2.3278(12), 2.3451(11) Å in 7+), and the P-Ru-Cl and/
or P-Ru-P and Cl-Ru-Cl angles are unexceptional
for (arene)rutheniumchlorophosphine derivatives.17,18,53
The Ru-C distances are slightly longer in the cation
(range for 7+ 2.222(4)-2.312(4) Å) than in the neutral
complex (range for 3 2.168(2)-2.244(2) Å), but compare
well with the values found in related cationic or neutral
Ru(II)-p-cymene complexes. The neutral complex 3
shows a clear η4-η2 distortion, with two short bonds
(Ru-C(28) 2.168(2) Å, Ru-C(27) 2.179(2) Å) trans to
the Ru-P bond and four longer bonds (2.216(2)-2.244-
(2) Å) trans to the Ru-Cl bonds. This finding reflects
the higher trans influence of the phosphorus ligands and
(54) Smith, P. D.; Gelbrich, T.; Hursthouse, M. B. J . Organomet.
Chem. 2002, 659, 1.
(55) Severin, K. Chem. Eur. J . 2002, 8, 1515.
(56) Wheatley, P.; Kalck, P. Chem. Rev. 1999, 99, 3379.
(57) Stephan, W.; Nadasdi, T. T. Coord. Chem. Rev. 1996, 147, 147.
(58) Adams, R. D. In Comprehensive Organometallic Chemistry II;
Wilkinson, G., Stone, F. G. A., Abel, E. W., Eds.; Pergamon: Oxford,
1995; Vol. 10, p 1.
(53) Pinto, P.; Marconi, G.; Heinemann, F. W.; Zenneck, U. Orga-
nometallics 2004, 23, 374.

4292 Organometallics, Vol. 23, No. 18, 2004
Berenguer et al.
Sch em e 2
acterized by elemental analyses, IR, 31P{1H}, and 19F
NMR spectroscopy, mass spectrometry ES(+), and, in
the case of 12a , X-ray diffraction methods. Thus, the
IR spectra of complexes 11a-13a exhibit only a medium-
intensity ν(CtC) band at ca. 1990 cm-1 (1989 11; 1990
12, 1987 cm-1 13), typical of bridging µ-PPh2CtCR
ligands.43,46-48 As expected, complex 14a , containing the
CtC-C6H4-CtC-Ph diynyl fragment, shows the pres-
ence of free (2170 cm-1) and bridging (1965 cm-1) CtC
alkynyl units.
In addition, we obtained crystals of 12a , which were
suitable for single-crystal X-ray diffraction analysis, and
examination of several crystals, as we have noted,
revealed the presence of only one isomer, the mixed (µ-
Cl)(µ-κP:η2-PPh2CtCR) bridged form. Complex 12a
crystallizes in the chiral space group P212121, with four
symmetry-related molecules of only one enantiomer at
the ruthenium center (S) and four acetone solvent
molecules in the unit cell. We noted that the crystal
structure of another crystal chosen from the same
sample gives the same structure, but showing an
absolute configuration R at the Ru, thus indicating that
both enantiomers are present in the crystalline mixture.
The molecular structure of 12a is presented in Figure
2, and selected bond lengths and angles are given in
Table 2. It is noteworthy that, despite the presence of
two chloride ligands in the precursor, in the final
binuclear compound the organometallic ruthenium frag-
ment has a preference in the solid state to act as a mixed
Cl,η2(alkyne) bidentate ligand toward the “cis-Pt(C6F5)2”
entity. The ruthenium atom presents the typical piano-
stool geometry, with the p-cymene ligand coordinated
in the usual η6-mode, and the platinum center has the
expected square-planar geometry. The Ru(1)-Cl(1)
bridging distance (2.4413(16) Å) is slightly longer than
F igu r e 2. ORTEP view of [(η6-p-cymene)ClRu(µ-Cl)(µ-1κP:
η2-PPh2CtCtBu)Pt(C6F5)2], 12a . Ellipsoids are drawn at
the 50% probability level. Hydrogen atoms have been
omitted for clarity.
the terminal Ru(1)-Cl(2) (2.3941(18) Å) bond length and
comparable to that previously found in [(PPh2CtCPh)-
Cp*Ru(µ-Cl)(µ-1κP:η2-PPh2CtCPh)Pt(C6F5)2], A.48 The
Pt-Cl (2.4116(15) Å) and η2-Pt-C(1),C(2) acetylenic
(2.177(6), 2.218(7) Å) bond distances are very close to
those found in A (Pt-Cl 2.3785(9) Å; Pt-C(acetylenic)
2.229(3), 2.226(4) Å). However, the degree of folding of
the tert-butylethynyl portion in the phosphine ligand
caused by coordination to the Pt atoms was found to be
significantly greater than that seen in the phenyleth-
ynyl fragment in complex A (angles at C(1) and C(2),
155.1(6)° and 159.2(2)° in 12a vs 162.3° and 166.3° in
A). The Ru-Pt separation, 4.121 Å, consistent with the

Ru/ Pt Heterobimetallic Complexes
Organometallics, Vol. 23, No. 18, 2004 4293
t
F igu r e 3. Variable-temperature 19F NMR spectra of 12 (12a (*) + 12b (b), R ) Bu) in CD3COCD3.
Ta ble 2. Selected Bon d Len gth s [Å] a n d An gles
[d eg] for [(η6-p-cym en e)ClRu (µ-Cl)-
(µ-1KP :η2-P P h 2CtCtBu )P t(C6F 5)2]‚(a ceton e)
(12a ‚a ceton e) a n d
cymene)(PPh2CtCR)Ru(µ-Cl)2Pt(C6F5)2] (b) were present
in solution. The presence of both isomers in solution,
but only one in the solid state, suggests the occurrence
of crystallization-induced transformation, probably due
to steric reasons in the lattice. In the 31P{1H} NMR
spectra, two singlets corresponding to both isomers
appeared. The resonance that appears significantly low
field shifted (δ(P) 46.32-48.55) with respect to the
corresponding precursor is attributed to the bridging
phosphine ligand in the isomer a . Similar downfield
shifts (∆(δP)) from 47.88 ppm for 14a to 55.49 ppm for
12a ) have been previously observed in other complexes
containing µ-κP:η2-PPh2CtCR ligands, this being at-
tributed to the loss of the electron ring current upon
complexation.46-48 The less deshielded signal, which in
each case appears relatively close to the corresponding
one in the precursor, is attributed to the minor isomer
in CDCl3 (δ(P) 7.10-9.80) stabilized by chloride bridges.
[(η6-p-cym en e)(P P h 2CtCTol)Ru (µ-Cl)-
(µ-1KP :η2-P P h 2CtCTol)P t(C6F 5)2](OTf)‚2CHCl3
(17‚2CHCl3)
12a ‚(CH3)2CO)
17‚2CHCl3
Pt-Cipso(C6F5)
2.033(7)
2.023(6)
2.4116(15)
2.177(6)
2.218(7)
2.030(4)
2.025(4)
2.4081(9)
2.188(4)
2.229(4)
Pt-Cl
Pt-CR
Pt-Câ
Ru-η6-C(arene)
Ru-P(b)
Ru-P(t)
Ru-Cl(b)
Ru-Cl(t)
P-CR(b)
P-CR(t)
2.167(7)-2.246(6) 2.236(4)-2.328(4)
2.3194(18)
2.3390(10)
2.3346(11)
2.4140(11)
2.4413(16)
2.3941(18)
1.766(6)
1.782(5)
1.745(5)
1.241(6)
1.191(6)
4.094
87.88(17)
89.87(11)
100.96(16)
85.20(16)
32.63(15)
81.89(11)
96.12(10)
87.48(4)
89.03(4)
CR-Câ(b)
CR-Câ(t)
Pt-Ru
1.199(9)
4.121
1
Variable-temperature H and 19F NMR spectra indicate
a temperature dependence of the spectral patterns and
also of the molar ratio between the isomers, the mixed
bridged form a increasing as the temperature is lowered.
It should be noted that complex 12a is only sparingly
Cipso(C6F5)-Pt-Cipso(C6F5) 90.1(3)
cis Cl-Pt-Cipso(C6F5)
cis CR-Pt-Cipso(C6F5)
cis Câ-Pt-Cipso(C6F5)
CR-Pt-Câ
87.39(17)
99.2(3)
86.0(3)
31.6(2)
83.28(17)
96.39(18)
88.26(6)
87.11(6)
85.81(6)
1
soluble in CDCl3 (enough for a H NMR spectrum), and
Cl-Pt-CR
Cl-Pt-Câ
the 19F NMR spectra were recorded in acetone-d6. In
this solvent the ratio 12a :12b is nearly temperature
independent, being ∼30:70 at 200 K, which is similar
to that observed at 293 K. In all complexes, the presence
of separated patterns for both isomers, even at high
temperature, indicates that their interconversion is slow
on the NMR time scale. To illustrate this, the temper-
ature dependence of the 19F NMR spectra of 12 in CD3-
P(b)-Ru-Cl(b)
P-Ru-Cl
Cl-Ru-Cl
P-Ru-P
94.01(4)
116.22(4)
159.4(4)
175.0(4)
166.0(4)
179.0(5)
Ru-Cl-Pt
116.27(7)
155.1(6)
P-CR-Câ(b)
P-CR-Câ(t)
CR-Câ-Cγ(b)
159.2(7)
CR-Câ-Cγ(t)
1
COCD3 and of the H NMR spectra for 13 in CDCl3 are
shown in Figures 3 and 4. As can be observed, the
limiting low-temperature 19F spectrum of 12 shows a
pattern compatible with a static structure for both
isomers, indicating that the rotation of C6F5 groups
about the Pt-C bond is hindered. In all complexes
studied, the signals due to m-fluorine atoms appear
partially overlapped or are coincident. Upon raising the
temperature, the rotation of C6F5 rings becomes rapid
open Ru(1)-Cl(1)-Pt(1) angle (116.27(7)°), excludes any
direct intermetallic interaction.
Notwithstanding, the 1H, 31P{1H}, and 19F NMR
spectroscopy clearly showed the presence of two species
at room temperature in a ca. 55-60:45-40 proportion
in CDCl3 and ca. 25-30:75-70 in acetone-d6, suggesting
that both of the possible isomers [(η6-p-cymene)ClRu-
(µ-Cl)(µ-1κP:η2-PPh2CtCR)Pt(C6F5)2] (a ) and [(η6-p-

4294 Organometallics, Vol. 23, No. 18, 2004
Berenguer et al.
1
F igu r e 4. Variable-temperature H NMR spectra in a selected region (C6H4 and CHMe2, p-Cy) of 13 (13a (*) + 13b (b),
R ) (4-CH3)C6H4) in CDCl3.
in the two isomers. Based on the coalescence of the
o-fluorine signals, the calculated energy barriers are
∆Gq270 ≈ 54 kJ ‚mol-1 for 12b, ∆Gq290 ≈ 51 kJ ‚mol-1 and
∆Gq318 ≈ 57 kJ ‚mol-1 for 12a . The behavior of the other
complexes is similar, but the NMR spectra were re-
corded in CDCl3, and in this solvent at low temperature
the major isomer observed is the mixed bridged (238 K;
for 11a :11b and 14a :14b 75:25 and for 13a :13b 80:20,
see Experimental Section for details).
Cl, followed by a reorientation of the cis-Pt(C6F5)2(η2-
alkyne) unit, and bonding to the other chlorine ligand.
Despite the presence of mixtures of binuclear species
11a -14a /11b-14b, the cyclic voltammograms of these
complexes in CH2Cl2 exhibit only an irreversible oxida-
tion wave in the narrow range from 1.17 to 1.26 V. In
each case, the wave is attributed to the RuII/III couple,
being significantly positively shifted (∆(mV) 483 11, 480
12, 420 13, 478 14) compared to that of the correspond-
ing neutral precursor (1-4), which is consistent with
electron donation through the bridging ligand (Cl or
phosphine) to the more electron-deficient Pt center.
As shown in Scheme 2 (ii), treatment of the bis-
(diphenyl)ethynylphosphine cationic derivatives 6-8
with [cis-Pt(C6F5)2(thf)2] in CH2Cl2 yielded cationic
heterobridged heterobimetallic complexes [(η6-p-cy-
mene)(PPh2CtCR)Ru(µ-Cl)(µ-1κP:η2-PPh2CtCR)Pt(C6-
The 1H NMR resonances of the doubly chloride-
bridged species 11b-14b are unexceptional and, as
expected, do not change appreciably with the temper-
ature. On the contrary, in the mixed bridged isomers
11a -14a , in which coordination of only one of the two
chloride ligands creates chirality at the ruthenium
center, the expected nonequivalence of the two halves
of the p-cymene ligands was only distinguishable at
room temperature for the tert-butylethynylphosphine
derivative 12a and for the remaining complexes at low
temperature. As can be observed in Figure 4, which
shows a section of the temperature dependence of the
1H spectra for 13, at 293 K only two arene (C6H4) and
one methyl (d, CH(CH3)2) resonances are seen for the
p-cymene ligand in the isomer 13a ; the CH singlet at
ca. 5.2 ppm was extremely broad, suggesting that this
temperature was close to the coalescence point. By
lowering the temperature, the ratio 13a :13b increases
and the CH (C6H4) and Me (CH(CH3)2) resonances
broaden, collapse, and, finally, split. At the low-
exchange limit, all four arene-ring protons and the two
methyl groups of the CHMe2 entity became inequiva-
lent. The latter give rise to two different doublets
(δ 0.95, 0.83) with identical integrated intensities. In
this complex (13a ), the coalescence temperature for the
methyl resonances and for the CH signals located at
4.71 and 5.78 ppm were measured at 263 and 288 K,
respectively, both data treatments yielding an energy
barrier of ca. 54 kJ ‚mol-1. Similar barriers were mea-
sured for complexes 11a (≈53.8 kJ ‚mol-1) and 14a (53.9
(Me) and 54.5 (CH) kJ ‚mol-1). As the two C6F5 rings
are nonequivalent even at high temperature, the ob-
served equilibration of the two halves of the p-cymene
ligand is probably caused by a fast rupture of the Pt-
t
F5)2](OTf) (R ) Ph 15, Bu 16, (4-CH3)C6H4 17), which
are isolated as air-stable yellow solids in high yields
(71-95%). All attempts to obtain analogous bimetallic
complexes under similar reaction conditions starting
from 9 and 10 were fruitless. Complexes 15-17, whose
acetone solutions behave as the expected 1:1 electro-
lytes, have been characterized by usual spectroscopic
techniques and, in the case of the tolylethynyl derivative
complex 17, its structure confirmed by an X-ray diffrac-
tion study. Their IR spectra confirm the presence of
bridging (ν(CtC) 1988 15, 1977 16, and 1972 cm-1 17)
and terminal (ν(CtC) 2168 15, 2165 16, and 2170 cm-1
17) PPh2CtCR ligands. The 31P{1H} NMR spectra also
confirm the inequivalence of both phosphine ligands
displaying two doublets in the range 36.51-51.55 ppm
and 0.72-2.98 ppm (2J P-P 53 Hz 15, 17 and 51 Hz 16),
respectively. The low-field signal, which is strongly
deshielding in relation to the corresponding precursor,
is attributed, as in isomers 11a -14a , to the bridging
phosphine ligand, and the high-field resonance, which
appears close to those seen in the precursors, is assigned
to the terminal P-coordinated ligand. Due to the chiral-
ity of the formed binuclear derivatives, all four arene
ring protons and the methyl groups of the CHMe2 entity
in the p-cymene ligand became inequivalent. As ex-
pected, the latter give rise to two different doublets in

Ru/ Pt Heterobimetallic Complexes
Organometallics, Vol. 23, No. 18, 2004 4295
F igu r e 5. Variable-temperature 19F NMR spectra of [(η6-p-cymene){(PPh2CtC(4-CH3)C6H4}Ru(µ-Cl)µ-1κP:η2-PPh2CtC-
(4-CH3)C6H4}Pt(C6F5)2](OTf), 17, in CDCl3.
their 1H spectra with identical intensities in the spec-
troscopic range 0.98-1.1 ppm.
The temperature dependence of the 19F NMR spectra
of complexes 15 and 17 is similar. In both complexes,
the rotation of one C6F5 group around the Pt-i-C bond
is hindered over all the range of temperatures studied
(-40 to 40 °C), while the energy barrier for the other is
lower, being static only at low temperature, as is clearly
seen in Figure 5 for complex 17 (see Experimental
Section for details). The free energy of activation ∆Gq
for the dynamic ring calculated, using the ortho and
meta fluorine resonances, is 51.7 ( 0.1 kJ ‚mol-1 in
complex 17 and 52.5 ( 0.1 kJ ‚mol-1 in complex 15. The
dynamic behavior observed for one ring is tentatively
ascribed to the less sterically hindered C6F5 group
mutually cis to the µ-Cl bridging group. We noted that
the rotation of this ring could be more easily achieved,
due to the fact that it is located trans to the η2-acetylenic
entity, which is known to have a higher trans-influence
than the chlorine group. In the tert-butylethynylphos-
phine complex 16, both C6F5 rings are static in the
limiting low-temperature spectrum, but exhibit a simi-
F igu r e 6. Molecular structure of the cation [(η6-p-cymene)-
{PPh2CtC(4-CH3)C6H4}Ru(µ-Cl)µ-1κP:η2-PPh2CtC(4-CH3)-
C6H4}Pt(C6F5)2](OTf) in 17. Ellipsoids are drawn at the
50% probability level. Hydrogen atoms have been omitted
for clarity.
lar dependence upon temperature (∆Gq
) 47.1 and
253
neutral bimetallic complex 12a . Finally, coordination of
the acetylenic fragment C(1)-C(2) to Pt has a percep-
tible effect on both the bond length (1.241(6) Å in C(1)t
C(2) vs 1.191(6) Å in C(22)tC(23)) and the linearity of
the acetylenic group. Angles at C(1) and C(2) have
values of 159.4(4)° and 166.0(4)°, respectively, compared
with 175.0(4)° (angle at C(22)) and 179.0(5)° (angle at
C(23)) on the uncoordinated acetylenic fragment. For
complex 16 no electrochemical response was observed
from -1.8 to +1.8 V. By contrast, the binuclear com-
pounds 15 and 17, as observed for their cationic 6 and
8 precursors, again do not give electrochemical response
in CH2Cl2 from 0 to 1.8 V. However, they show a quasi
reversible reduction wave at -0.95 V for complex 15,
and at -1.016 V for complex 17, and in the correspond-
ing reverse scan one irreversible small anodic peak
(-0.445 V 15, -0.502 V 17). Both the cathodic and the
small anodic peak are notably more positive (∆(mV) 640
V (c), 577 V (a) 15; 650 V (c), 542 V (a) 17) compared to
those observed in the precursors.
48.3 kJ ‚mol-1, respectively, for the o-F, see Experimen-
tal Section for details).
The structure proposed for these 15-17 binuclear
complexes has been confirmed by X-ray crystallography,
using a single crystal of 17, obtained from slow diffusion
of n-hexane into a solution of 17 in CHCl3 at room
temperature (see Figure 6). Relevant distances and
angles are shown in Table 2. Complex 17 crystallizes
in the centrosymmetric group P1h, with both enanthio-
morphic cations at the Ru center, S and R, present in
the unit cell, showing the expected piano-stool type
geometry at the ruthenium center and square-planar
at the platinum atom. The chelate bite angle Cl(1)-Ru-
(1)-P(1) (87.48(4)°) and the angles P(1)-Ru(1)-P(2)
(94.01(4)°) and P(2)-Ru(1)-Cl(1) (89.03(4)°) are similar
to those found in [(PPh2CtCPh)Cp*Ru(µ-Cl)(µ-PPh2Ct
CPh)Pt(C6F5)2], A. The Ru-P(1) bridging length is
identical within the experimental error (2.3390(10) Å)
to the terminal Ru-P(2) distance (2.3346(11) Å) and
comparable to those found in cation 7+ (2.3278(12),
2.3451(11) Å). The Pt-C(alkyne) bond distances (2.188-
(4) and 2.229(4) Å), the angle at the bridging chloride
atom (Ru(1)-Cl(1)-Pt(1) 116.22(4)°), and the Ru-Pt
separation (4.094 Å) are similar to those found in the
Con clu sion s
In conclusion, we report the synthesis and properties
of some potentially useful neutral [(η6-p-cymene)RuCl2-

4296 Organometallics, Vol. 23, No. 18, 2004
Berenguer et al.
(PPh2CtCR)] (1-5) and cationic [(η6-p-cymene)RuCl-
(PPh2CtCR)2]X (6-10) ruthenium complexes, bearing
one or two diphenylphosphinoacetylene ligands, and
investigate their reactivity toward the solvento species
[cis-Pt(C6F5)2(thf)2]. 13C{1H} NMR studies on the mono-
nuclear complexes (1-10) suggest that the alkyne
polarization on the PPh2CtCR ligand upon P-coordina-
tion is perceptibly higher in the cationic (6-10) com-
plexes than in the neutral derivatives (1-5) and, in the
latter, clearly enhanced with respect to those of free
PPh2CtCR ligands. This spectroscopic behavior is
entirely similar to that seen with the isoelectronic “M-
(η5-C5Me5)” (M ) Rh, Ir(III)) moieties and the PPh2Ct
CPh ligand, but contrasts with the fact that complex-
ation of two PPh2CtCPh to the neutral “Ru(η5-C5Me5)Cl”
fragment has been observed to have no effect on the
alkyne polarization. We have shown that the neutral
complexes react with [cis-Pt(C6F5)2(thf)2] to yield het-
erobimetallic compounds (11a -14a ), stabilized in the
solid state by a (µ-Cl)(µ-PPh2CtCR) bridging system,
as has been confirmed by X-ray crystallography on
complex 12a . In solution, these neutral bimetallic Ru-
(II)-Pt(II) complexes exist as a mixture of isomers (µ-
Cl)(µ-PPh2CtCR) 11a -14a /(µ-Cl)2 11b-14b, which
interconvert slower than the NMR time scale. It has
been observed that the heteromixed bridged isomers
type a are more favorable in chloroform than in acetone,
but are disfavored at higher temperatures. The exist-
ence of only one isomer (a ) in the solid state with the
“(η6-arene)RuCl2” fragment contrasts with the presence
of both isomers (a + b, 1:1) previously observed with
the isoelectronic “Ir(η5-C5Me5)Cl2” unit or the doubly
chloride-bridged isomer (b) seen with the “Rh(η5-C5Me5)-
Cl2” moiety. Chiral cationic bimetallic d6-d8 complexes
[(η6-p-cymene)(PPh2CtCR)Ru(µ-Cl)(µ-1κP:η2-PPh2Ct
CR)Pt(C6F5)2](OTf) (15-17) have also been prepared
starting from the cationic mononuclear complexes 6-8
and the synthon “cis-Pt(C6F5)2”. In contrast to related
chiral neutral isomers 11a -14a , the heterobridged
system, in these cationic 15-17 compounds, was found
to be stable in solution, making both halves of the
p-cymene ligand nonequivalent. Finally, as is often
found in other fluoroaryl complexes of Pt, the rotation
of the C6F5 groups around the Pt-C6F5 bond is clearly
hindered in the limiting low-temperature 19F spectra of
all bimetallic 11-17 complexes. Furthermore, the pres-
ence of different ligands trans to the C6F5 rings in
isomers 11a -14a and complexes 15-17 usually induces
different rotation energy barriers for the C6F5 groups.
F igu r e 7. Labeling scheme for the carbon atoms in
p-cymene and arylethynylphosphine.
PPh2CtCR ligands (R ) Ph,49 tBu,49 Tol50). The novel alkyn-
ylphosphines PPh2CtCC6H4CtCC6H5 and PPh2CtCC6H4CN
used in this work have been prepared following the general
procedure described by Carty et al.,49 and their analytical and
spectroscopic data are included in this work.
Cyclic voltammetric studies were performed using an EG&G
model 283 potentiostat/galvanostat. The three-electrode sys-
tem consists of a working platinum disk electrode, an auxiliary
platinum wire electrode, and a saturated calomel reference
(SCE). The measurements were carried out in anhydrous CH2-
Cl2 solution under N2 in the test compounds and 0.1 M in
(NBu4)[PF6] as supporting electrolyte. The values are given
versus FeCp2+/FeCp2 under the experimental conditions em-
ployed.
Figure 7 shows the labeling scheme for the carbon atoms
in the p-cymene and in the arylethynylphosphine.
Da ta for P P h 2CtC(4-CtCP h )C6H4. Yield: 72%. Anal.
Calcd for C28H19P: C, 87.03; H, 4.96. Found: C, 86.90; H, 4.74.
MS ES(+): m/z 389 [M + 3H]+ 16%; 387 [M + H]+ 4%; 285
[M - (CtCPh)]+ 100%. IR (cm-1): ν(CtC) 2166 (m), 2152 (m).
1H NMR (δ, CDCl3): 7.66 (3H), 7.49 (8H), 7.34 (8H) (aromatic,
1
C6H5 and C6H4). 13C{1H} NMR (δ, CDCl3): 136.2 (d, J C-P
)
)
6.3, i-C, Ph); 132.7 (d, 2J C-P ) 21.0, o-C, Ph); 131.8 (d, 4J C-P
1.4, C2, C6H4); 131.75 (C8, C6H5); 131.6 (d, J C-P ) 2.6, p-C,
4
Ph); 129.2 (C3, C6H4); 128.8 (d, J C-P ) 7.7, m-C, Ph); 128.6
3
(C10, C6H5); 128.5 (C9, C6H5); 123.9 (C7, C6H5); 123.2 (d,
3J C-P ) 4.5, C1, C6H4); 122.6 (C4, C6H4); 107.4 (d, J C-P ) 4.0,
2
Câ); 91.8, 91.4 (C5tC6); 89.2 (d, 1J C-P ) 11.1, CR). 31P{1H} NMR
(δ, CDCl3): -33.27 (s).
Da ta for P P h 2CtC(4-CN)C6H4. Yield: 26%. Anal. Calcd
for C21H14NP: C, 81.02; H, 4.53; N, 4.50. Analyses of several
samples always give lower values than expected: 76.23; 4.11;
3.58. MS ES(+): m/z 312 [M + H]+ 21%; 130 [M - Ph - C6H4-
CN - 2H]+ 100%. IR (cm-1): ν(CN) 2227 (s); ν(CtC) 2172 (m).
1H NMR (δ, CDCl3): 7.62 (8H), 7.37 (6H) (CH, Ph). 13C{1H}
1
NMR (δ, CDCl3): 135.3 (d, J C-P ) 6.2, i-C, Ph); 132.7 (d,
4
2J C-P ) 21.1, o-C, Ph); 132.2 (d, J C-P ) 1.4, p-C, Ph); 132.1
3
(C2, C6H4CN); 129.4 (C3, C6H4CN); 128.8 (d, J C-P ) 7.7, m-C,
Ph); 127.5 (d, 3J C-P ) 1.1, C1, C6H4CN); 118.4 (CN); 112.1 (C4,
2
1
C6H4CN); 105.6 (d, J C-P ) 3.0, Câ); 91.7 (d, J C-P ) 12.5, CR).
31P{1H} NMR (δ, CDCl3): -33.48 (s).
Syn t h esis of [(η6-p-cym en e)R u Cl2(P P h 2CtCR )] (R )
t
P h 1, Bu 2, Tol 3, C6H4CtCC6H5 4). Gen er a l P r oced u r e.
A solution of [(η6-p-cymene)RuCl2]2 (0.20 g, 0.33 mmol) in
acetone (10 mL) was treated with two molar equivalents of
the corresponding PPh2CtCR, and the mixture was stirred
for ca. 45 min. The resulting orange solid was isolated by
filtration, washed with diethyl ether (or ethanol in case of
complex 4), and dried under vacuum.
Exp er im en ta l Section
Da ta for 1. Yield: 84%. Anal. Calcd for C30Cl2H29PRu: C,
60.81; H, 4.93. Found: C, 60.86; H, 4.85. MS ES(+): m/z 559
[M - Cl]+ 100%. IR (cm-1): ν(CtC) 2171 (s); ν(Ru-Cl) 295
C, H, and N analyses, conductivities (acetone, ca. 5 × 10-4
mol‚L-1), and IR and NMR spectroscopies were performed as
described elsewhere,48 the temperature of the routine NMR
being 293 K. Literature methods were employed to prepare
1
(w), 283 (w). H NMR (δ, CDCl3): 8.04 (4H), 7.64 (2H), 7.5-
7.36 (9H) (Ph); 5.33, 5.26 (AA′BB′ system, J H-H ) 5.7, 4H,
C6H4, p-cym); 2.94 (sept, J H-H ) 6.9, 1H, CH, iPr); 1.98 (s, 3H,
[Ru(η6-p-cymene)Cl2]2 and [Pt(C6F5)2(thf)2]63 complexes and
i
51
CH3-C6H4); 1.17 (d, J H-H ) 6.9, 6H, CH3, Pr). 13C{1H} NMR
(δ, CDCl3): 133.2 (d, 2J C-P ) 10.4, o-C, Ph); 132.12 (d, 1J C-P
)
4
(59) Fornie´s, J .; Go´mez, J .; Lalinde, E.; Moreno, M. T. Chem. Eur.
J . 2004, 10, 888.
(60) Berenguer, J . R.; Fornie´s, J .; Lalinde, E.; Mart´ın, A.; Serrano,
B. J . Chem. Soc., Dalton Trans. 2001, 2926.
(61) Ara, I.; Berenguer, J . R.; Eguiza´bal, E.; Fornie´s, J .; Lalinde, E.
Organometallics 2001, 20, 2686.
(62) Ara, I.; Berenguer, J . R.; Eguiza´bal, E.; Fornie´s, J .; Lalinde,
E.; Mart´ın, A. Eur. J . Inorg. Chem. 2001, 1631.
(63) Uso´n, R.; Fornie´s, J .; Toma´s, M.; Menjo´n, B. Organometallics
1985, 4, 1912.
54, i-C, Ph); 132.1 (d, J C-P ) 1.5, o-C, CtCPh); 130.4 (d,
4J C-P ) 2.7, p-C, Ph); 130.3 (p-C, CtCPh); 128.7 (m-C,
CtCPh); 127.9 (d, 3J C-P ) 10.9, m-C, Ph); 120.9 (d, 3J C-P ) 3,
2
i-C, CtCPh); 109.4 (d, J C-P ) 1.3, C4, p-cym); 109.0 (d,
2
2J C-P ) 11.7, Câ); 96.1 (C1, p-cym); 90.5 (d, J C-P ) 4.4, C3,
2
1
p-cym); 86.7 (d, J C-P ) 6, C2, p-cym); 83.6 (d, J C-P ) 89.4,
CR); 30.3 (C6, p-cym); 21.9 (C7, p-cym); 17.6 (C5, p-cym). 31P-
{1H} NMR (δ, CDCl3): -2.17 (s). Ep ) 0.72 V (reversible).
a

Ru/ Pt Heterobimetallic Complexes
Organometallics, Vol. 23, No. 18, 2004 4297
3
Da ta for 2. Yield: 94%. Anal. Calcd for C28Cl2H33PRu: C,
58.74; H, 5.81. Found: C, 58.73; H, 6.10. MS ES(+): m/z 572
[M]+ 12.9%; 1109 [2M - Cl]+ 13%; 539 [M - Cl]+ 100%. IR
(cm-1): ν(CtC) 2166 (m); ν(Ru-Cl) 296 (w). 1H NMR (δ,
CDCl3): 7.96 (m, 4H), 7.33 (m, 6H) (Ph); 5.29, 5.21 (AA′BB′
system, J H-H ) 5.6, 4H, C6H4, p-cym); 2.91 (sept, J H-H ) 6.9,
(d, J C-P ) 2.9, C1, C6H4CN); 118 (CN); 113.3 (C4, C6H4CN);
109.7 (C4, p-cym); 106.3 (d, 2J C-P ) 10.2, Câ); 96.6 (C1, p-cym);
90.3 (d, 2J C-P ) 4.3, C3, p-cym); 88.0 (d, 1J C-P ) 84.6, CR); 86.7
2
(d, J C-P ) 5.9, C2, p-cym); 30.4 (C6, p-cym); 21.9 (C7, p-cym);
17.6 (C5, p-cym). 31P{1H} NMR (δ, CDCl3): 1.16 (s). Ep ) 0.74
a
V (reversible).
i
t
Syn th esis of [(η6-p-cym en e)Ru Cl(P P h 2CtCR)2](OTf)
(R ) P h 6, tBu 7, Tol 8, C6H4CtCC6H5 9). Gen er a l
P r oced u r e. A solution of [(η6-p-cymene)RuCl2(PPh2CtCR)]
(0.17 mmol) in acetone (10 mL) was stirred with AgOTf (0.04
g, 0.17 mmol) for 2 h in the absence of light. Then, the solution
was filtered and treated with 0.17 mmol of the corresponding
PPh2CtCR. After 5 min of stirring the solvent was evaporated
to dryness and addition of diethyl ether (for 6 and 9) or
n-hexane (for 7 and 8) caused the precipitation of the final
complexes as yellow solids.
1H, CH, Pr); 1.92 (s, 3H, CH3-C6H4); 1.43 (s, 9H, CH3, Bu);
i
1.18 (d, J H-H ) 6.9, 6H, CH3, Pr). 13C{1H} NMR (δ, CDCl3):
2
1
132.8 (d, J C-P ) 10.4, o-C, Ph); 132.3 (d, J C-P ) 54, i-C, Ph);
4
3
129.9 (d, J C-P ) 2.7, p-C, Ph); 127.5 (d, J C-P ) 10.9, m-C,
Ph); 119.3 (d, J C-P ) 10.4, Câ); 109.0 (C4, p-cym); 95.3 (C1,
2
p-cym); 90.3 (d, J C-P ) 4.4, C3, p-cym); 86.4 (d, J C-P ) 6, C2,
2
2
p-cym); 73.1 (d, 1J C-P ) 93.1, CR); 30.3 (d, 4J C-P ) 1.1, C(CH3)3);
30.0 (C6, p-cym); 28.8 (d, 3J C-P ) 1.9, C(CH3)3); 21.8 (C7, p-cym);
17.3 (C5, p-cym). 31P{1H} NMR (δ, CDCl3): -3.94 (s). Ep
)
a
0.69 V (reversible).
Da ta for 3. Yield: 87%. Anal. Calcd for C31Cl2H31PRu: C,
61.39; H, 5.15. Found: C, 61.14; H, 5.11. MS ES(+): m/z 571
[M - Cl]+ 100%; 537 [M - 2Cl + H]+ 74%. IR (cm-1): ν(CtC)
Da ta for 6. Yield: 53%. Anal. Calcd for C51ClF3H44O3P2-
RuS: C, 61.72; H, 4.47; S, 3.23. Found: C, 61.36; H, 4.19; S,
3.17. ΛM: 112 Ω-1‚cm2‚mol-1. MS ES(+): m/z 844 [M - OTf]+
39%; 709 [RuCl(PPh2CtCPh)2]+ 26%; 557 [RuCl(PPh2CtCPh)-
(cym)]+ 100%. IR (cm-1): ν(CtC) 2171 (s); ν(OTf) 1275 (s), 1224
1
2170 (s); ν(Ru-Cl) 300 (m). H NMR (δ, CDCl3): 8.04 (m, 4H,
Ph), 7.53 (d, J H-H ) 7.8, 2H, CH, Tol), 7.36 (m, 6H, Ph), 7.22
(d, J H-H ) 7.8, 2H, CH, Tol); 5.33, 5.26 (AA′BB′ system,
J H-H ) 5.7, 4H, C6H4, p-cym); 2.93 (sept, J H-H ) 6.9, 1H, CH,
iPr); 2.40 (s, 3H, CH3, Tol); 1.97 (s, 3H, CH3-C6H4); 1.17 (d,
J H-H ) 6.9, 6H, CH3, iPr). 13C{1H} NMR (δ, CDCl3): 140.9 (C4,
1
(s), 1154 (s), 1032 (s); ν(Ru-Cl) 310 (w). H NMR (δ, CDCl3):
8.10 (4H), 7.48 (16H), 7.3 (4H), 7.08 (2H), 6.98 (4H) (Ph); 5.76
(d), 5.21 (d) (J H-H ) 5.4, 4H, C6H4 p-cym); 2.62 (sept, J H-H
)
6.8, 1H, CH, iPr); 2.24 (s, 3H, CH3-C6H4); 1.14 (d, J H-H ) 6.8,
2
4
1
6H, CH3, iPr). 13C{1H} NMR (δ, CDCl3): 134.9 (AXX′, | J C-P
+
Tol); 133.2 (d, J C-P ) 10.4, o-C, Ph); 132.1 (d, J C-P ) 1.4,
1
4
3J C-P| ) 58.5, i-C, Ph); 132.2 (s, o-C, CtCPh), 132.2 (“t”,
CH, Tol); 132.3 (d, J C-P ) 53.8, i-C, Ph); 130.4 (d, J C-P
)
2.6, p-C, Ph); 129.5 (CH, Tol); 128.0 (d, 3J C-P ) 10.9, m-C, Ph);
117.9 (d, 3J C-P ) 3, C1, Tol); 109.48 (d, 2J C-P ) 12.2, Câ); 109.45
2
4
2
4
| J C-P + J C-P| ) 10.4, o-C, Ph), 131.8 (“t”, | J C-P + J C-P| )
11.5, o-C, Ph), 131.7 (s, p-C, Ph), 131.0 (p-C, Ph), 130.8 (“t”,
(d, J C-P ) 1.3, C4, p-cym); 96.1 (C1, p-cym); 90.6 (d, J C-P
)
)
2
2
1
| J C-P + 3J C-P| ) 56.1, i-C, Ph), 130.6 (p-C, CtCPh); 129.1 (“t”,
4.5, C3, p-cym); 86.8 (d, J C-P ) 6, C2, p-cym); 83.0 (d, J C-P
2
1
3
5
| J C-P + J C-P| ) 11.5, m-C, Ph); 128.9 (m-C, CtCPh); 128.2
90.6, CR); 30.4 (C6, p-cym); 22.0 (C7, p-cym); 21.7 (CH3, Tol);
(“t”, | J C-P + 5J C-P| ) 11.2, m-C, Ph); 119.9 (i-C, CtCPh); 118.9
3
17.6 (C5, p-cym). 31P{1H} NMR (δ, CDCl3): -2.46 (s). Ep
)
a
(C4, p-cym); 113.2 (AXX′, | J C-P + 4J C-P| ) 13.8, Câ); 101.5 (C1,
2
p-cym); 98.8 (C3, p-cym); 92.3 (t, J C-P ) 4.5, C2, p-cym); 79.0
2
0.70 V (reversible).
(AXX′, | J C-P + 3J C-P| ) 105.3, CR); 31.1 (C6, p-cym); 21.5 (C7,
1
Da ta for 4. Yield: 61%. Anal. Calcd for C38Cl2H33PRu: C,
65.90; H, 4.80. Found: C, 65.53; H, 4.76. MS ES(+): m/z 657
[M - Cl]+ 100%. IR (cm-1): ν(CtC) 2167 (m); ν(Ru-Cl) 290
p-cym); 17.2 (C5, p-cym). 19F NMR (δ, CDCl3): -78.29 (s, CF3).
31P{1H} NMR (δ, CDCl3): 5.74 (s). Epc ) -1.59 V (irreversible);
a
1
Ep ) -1.022 V (irreversible, small).
(m). H NMR (δ, CDCl3): 8.03 (m, 4H), 7.57 (m, 7H), 7.34 (m,
8H) (CH, Ph); 5.33, 5.26 (AA′BB′ system, J H-H ) 5.4, 4H, C6H4,
Da ta for 7. Yield: 84%. Anal. Calcd for C47ClF3H52O3P2-
RuS: C, 59.27; H, 5.5; S, 3.37. Found: C, 59.10; H, 4.98; S,
2.92. ΛM: 119 Ω-1‚cm2‚mol-1. MS ES(+): m/z 803 [M - OTf]+
100%. IR (cm-1): ν(CtC) 2165 (s); ν(OTf) 1271 (s), 1223 (s),
1150 (s), 1031 (s); ν(Ru-Cl) 306 (w). 1H NMR (δ, CDCl3): 7.98
(m, 4H), 7.42 (m, 8H), 7.22 (m, 4H), 7.1 (m, 4H) (Ph); 5.67 (d),
5.16 (d) (J H-H ) 6.1, 4H, C6H4, p-cym); 2.60 (sept, J H-H ) 6.9,
1H, CH, iPr); 2.11 (s, 3H, CH3-C6H4); 1.39 (s, 18H, CH3, tBu);
p-cym); 2.93 (sept, J H-H ) 6.7, 1H, CH, iPr); 1.98 (s, 3H, CH3-
i
C6H4); 1.17 (d, J H-H ) 6.7, 6H, CH3, Pr). 13C{1H} NMR (δ,
2
4
CDCl3): 133.3 (d, J C-P ) 10.4, o-C, Ph); 132.13 (d, J C-P
)
1.9, C2, C6H4); 131.12 (d, 1J C-P ) 55, i-C, Ph); 131.84 (C3, C6H4);
131.75 (C8, C6H5); 130.6 (d, J C-P ) 2.3, p-C, Ph); 128.8 (C10
,
4
C6H5); 128.5 (C9, C6H5); 128.1 (d, 3J C-P ) 10.9, m-C, Ph); 125.4,
122.7 (C4, C6H4, C7, C6H5); 120.6 (d, J C-P ) 2.9, C1, C6H4);
3
109.7 (C4, p-cym); 108.6 (d, 2J C-P ) 11.3, Câ); 96.5 (C1, p-cym);
i
1.13 (d, J H-H ) 6.9, 6H, CH3, Pr). 13C{1H} NMR (δ, CDCl3):
92.7 (C5tC6); 90.5 (d, J C-P ) 4.4, C3, p-cym); 88.6 (C5tC6);
2
1
133.8 (AXX′, | J C-P
+
3J C-P| ) 58, i-C, Ph); 132.0 (AXX′,
86.8 (d, 2J C-P ) 5.9, C2, p-cym); 85.5 (d, 1J C-P ) 87.8, CR); 30.4
1
3
2
4
| J C-P + J C-P| ) 56.2, i-C, Ph); 131.8 (“t”, | J C-P + J C-P| )
(C6, p-cym); 22.0 (C7, p-cym); 17.7 (C5, p-cym). 31P{1H} NMR
11.2, o-C, Ph); 131.6 (“t”, | J C-P + 4J C-P| ) 10.3, o-C, Ph); 130.9
2
a
3
5
(δ, CDCl3): -1.16 (s). Ep ) 0.73 V (reversible).
(p-C, Ph); 130.2 (p-C, Ph); 128.3 (“t”, | J C-P + J C-P| ) 11.3,
3
5
Syn th esis of [(η6-p-cym en e)Ru Cl2(P P h 2CtCC6H4CN)]
(5). A solution of [(η6-p-cymene)RuCl2]2 (0.20 g, 0.33 mmol) in
acetone and 0.20 g of PPh2CtCC6H4CN (0.65 mmol) was
stirred for 1 h. After this time the orange solution obtained
was evaporated to dryness and the residue treated with diethyl
ether, yielding 5 as an orange solid that was isolated by
filtration and dried under vacuum. Yield: 89%. Anal. Calcd
for C31Cl2H31PRu: C, 60.30; H, 4.57; N, 2.27. Found: C, 59.97;
H, 4.97; N, 2.60. MS ES(+): m/z 1200 [NCC6H4CtCPPh2(cym)-
Ru(µ-Cl)3Ru(cym)PPh2CtCC6H4CN]+ 4%; 888 [(cym)Ru(µ-
Cl)3Ru(cym)PPh2CtCC6H4CN]+ 16%; 582 [M - Cl]+ 100%. IR
(cm-1): ν(CtN) 2228 (w); ν(CtC) 2176 (s); ν(Ru-Cl) 300 (m).
1H NMR (δ, CDCl3): 7.97 (m, 4H, Ph), 7.71, 7.69 (AA′BB′
system, J H-H ) 8.3, 4H, C6H4CN), 7.4 (m, 6H, Ph); 5.31, 5.25
(AA′BB′ system, J H-H ) 5.7, 4H, C6H4, p-cym); 2.88 (sept,
m-C, Ph); 127.8 (“t”, | J C-P + J C-P| ) 11.2, m-C, Ph); 122.8
(AXX′, | J C-P + 4J C-P| ) 11.4, Câ); 118.5 (C,4 p-cym); 99.8 (C1,
2
p-cym); 98.3 (C3, p-cym); 91.5 (t, J C-P ) 4.6, C2, p-cym); 70.4
2
(AXX′, | J C-P + 3J C-P| ) 105, CR); 30.6 (C6, p-cym); 30 (C(CH3)3);
1
28.9 (C(CH3)3); 21.2 (C7, p-cym); 16.7 (C5, p-cym). 19F NMR (δ,
CDCl3): -78.29 (s, CF3). 31P{1H} NMR (δ, CDCl3): 4.57 (s).
c
a
Ep ) -1.685 V (irreversible); Ep ) -1.111 V (irreversible,
small).
Da ta for 8. Yield: 92%. Anal. Calcd for C53ClF3H48O3P2-
RuS: C, 62.38; H, 4.74 S, 3.14. Found: C, 62.18; H, 4.91; S,
3.06. ΛM: 135 Ω-1‚cm2‚mol-1. MS ES(+): m/z 871 [M - OTf]+
100%. IR (cm-1): ν(CtC) 2169 (s); ν(OTf) 1264 (s), 1223 (s),
1150 (s), 1031 (s); ν(Ru-Cl) 305 (w). 1H NMR (δ, CDCl3): 8.1,
7.47, 7.36, 7.12, 6.96 (m, 28H, aromatics; Ph, Tol); 5.70 (d),
5.20 (d) (J H-H ) 6.0, 4H, C6H4 p-cym); 2.65 (sept, J H-H ) 6.7,
i
i
J H-H ) 6.9, 1H, CH, Pr); 1.98 (s, 3H, CH3-C6H4); 1.14 (d,
1H, CH, Pr); 2.40 (s, 6H, CH3, Tol); 2.22 (s, 3H, CH3-C6H4);
i
i
J H-H ) 6.9, 6H, CH3, Pr). 13C{1H} NMR (δ, CDCl3): 133.2 (d,
1.14 (d, J H-H ) 6.7, 6H, CH3, Pr). 13C{1H} NMR (δ, CDCl3):
3
1
2J C-P ) 10.5, o-C, Ph); 132.7 (d, J C-P ) 1.1, CH, C6H4CN);
141.6 (s, C,4 Tol); 135.4 (AXX′, | J C-P + 3J C-P| ) 58.2, i-C, Ph);
1
2
132.3 (CH, C6H4CN); 131.6 (d, J C-P ) 54, i-C, Ph); 130.7 (d,
132.2 (“t”, | J C-P
+
+
4J C-P| ) 10.3, o-C, Ph); 132.2 (CH, Tol);
4J C-P| ) 11.4, o-C, Ph); 131.6 (p-C, Ph);
3
2
4J C-P ) 2.3, p-C, Ph); 128.2 (d, J C-P ) 10.9, m-C, Ph); 125.7
131.7 (“t”, | J C-P

4298 Organometallics, Vol. 23, No. 18, 2004
Berenguer et al.
1
3
131.03 (AXX′, | J C-P + J C-P| ) 56, i-C, Ph); 130.5 (p-C, Ph);
Da ta for 11a . Yield: 73%. Anal. Calcd for C42Cl2F10H29
PPtRu: C, 44.97; H, 2.61. Found: C, 44.74; H, 2.33. MS ES-
(+): m/z 1149 [M + Na + 4H]+ 2%; 863 [M + Na
-
3
5
129.6 (CH, Tol); 129.1 (“t”, | J C-P + J C-P| ) 11.6, m-C, Ph);
128.2 (“t”, | J C-P + 5J C-P| ) 11.3, m-C, Ph); 118.0 (C4, p-cym);
-
3
116.9 (“t”, | J C-P + 5J C-P| ) 2.8, C1, Tol); 113.9 (AXX′, | J C-P
+
PPh2CtCPh+4H]+ 3%; 557 [M - Pt(C6F5)2 - Cl]+ 100%
(sample ionizated with Na+). IR (cm-1): ν(CtC) 1989 (m);
ν(C6F5)X-sens 810 (m), 797 (m); ν(Ru-Cl) 305 (w), 258 (w). In
solution, the observed ratio for the equilibrium 11a /11b at
room temperature is 55:45 in CDCl3 and 25:75 in HDA. 1H
NMR (δ, CDCl3): 8.18-7.11 (m, Ph, overlapped with those
corresponding to phenyl protons of 11b); 5.40 (s, C6H4, p-cym);
5.30 (s, vbr, C6H4, p-cym); 2.38 (sept, J H-H ) 6.7, CH, iPr); 1.95
3
2
4J C-P| ) 14.3, Câ); 101.4 (C1, p-cym); 99.1 (t, J C-P ) 4.4, C3,
2
p-cym); 92.19 (2J C-P ) 4.5, C2, p-cym); 78.4 (AXX′, | J C-P
+
1
3J C-P| ) 106.5, CR); 31.1 (C6, p-cym); 21.8, 21.5 (CH3, Tol and
C7, p-cym); 17.2 (C5, p-cym). 19F NMR (δ, CDCl3): -78.27 (s,
CF3). 31P{1H} NMR (δ, CDCl3): 4.77 (s). Ep ) -1.666 V
c
a
(irreversible); Ep ) -1.044 V (irreversible, small).
Da ta for 9. Yield: 60%. Anal. Calcd for C67ClF3H52O3P2-
RuS: C, 67.47; H, 4.39; S, 2.69. Found: C, 67.79; H, 4.73; S,
2.24. ΛM: 134 Ω-1‚cm2‚mol-1. MS ES(+): m/z 1044 [M - OTf]+
97%; 994 [M - OTf - Cl - CH3]+ 100%; 909 [M - OTf - cym]+
18%; 657 [M - OTf - PP2CtCC6H4CtCC6H5]+ 86%. IR (cm-1):
ν(CtC) 2171 (s); ν(OTf) 1264 (s), 1224 (s), 1154 (s), 1031 (s);
ν(Ru-Cl) 254 (w). 1H NMR (δ, CDCl3): 8.1, 7.8, 7.49, 7.32,
7.11 (m, 38H, CH, Ph); 5.80 (d), 5.26 (d) (J H-H ) 5.7, 4H, C6H4,
p-cym); 2.57 (sept, J H-H ) 7.0, 1H, CH, iPr); 2.26 (s, 3H, CH3-
i
(s, CH3-C6H4); 0.99 (d, J H-H ) 6.7, CH3, Pr). 11b: 5.81, 5.76
(AA′BB′ system, J H-H ) 5.7, C6H4, p-cym); 2.65 (sept, J H-H
)
i
6.8, CH, Pr); 1.93 (s, CH3-C6H4); 1.13 (d, J H-H ) 6.8, CH3,
iPr). The two aromatic (CH, C6H4), and methyl (d, CH(CH3)2)
resonances of p-cymene in 11a broaden as the temperature is
lowered, coalesce, and finally split: 5.73, 5.67, 5.27, 4.76 (CH);
0.97 (d, J H-H ) 5.0); 0.84 (d, J H-H ) 4.9). The ratio 11a :11b
observed at 223 K is 77:23. The Tc for the methyl groups is ca.
263 K (∆Gq ≈ 54.2 kJ ‚mol-1) and for the CH signals at 5.73
C6H4); 1.14 (d, J H-H ) 7.0, 6H, CH3, Pr). 13C{1H} NMR (δ,
i
263
and 4.76 ppm ca. 283 (∆Gq ≈ 53.8 kJ ‚mol-1). 19F NMR (δ,
1
3
CDCl3): 134.6 (AXX′, | J C-P + J C-P| ) 58.6, i-C, Ph); 132.5-
283
128.3 (aromatics); 126.1, 122.6 (C4 and C7, phosphine); 119.4
CDCl3, 282.5 MHz): at 238 K, the ratio 11a :11b is 75:25;
3
3
(C1, phosphine); 112.7 (AXX′, | J C-P + 4J C-P| ) 13.3, Câ); 102.0
2
-116.43 (d, J Pt-o-F ≈ 345), -117.18 (d, J Pt-o-F ≈ 415),
3
3
(C4, p-cym); 98.6 (C1, p-cym); 93.2 (C3, p-cym); 92.8 (C5tC6);
-120.63 (d, J Pt-o-F ≈ 400), -123.00 (d, J Pt-o-F ≈ 330) (o-F);
-160.13 (t, p-F); -161.30 (t, p-F); -162.92 (m), -164.22 (m)
(1:3 m-F). 11b: -119.28 (d, 3J Pt-o-F ≈ 500), -120.30 (d, 3J Pt-o-F
cannot be determined) (o-F); -163.18 (t, p-F); -165.02 (m),
-165.45 (m) (m-F). Upon heating, the ortho and meta signals
of both complexes broaden and the relative concentration of
11b increases. For 11a , the signals at -117.18 and -120.63,
88.6 (C5tC6); 88.5 (C2, p-cym); 80.5 (AXX′, | J C-P + J C-P| )
104, CR); 31.1 (C6, p-cym); 21.6 (C7, p-cym); 17.5 (C5, p-cym).
19F NMR (δ, CDCl3): -78.27 (s, CF3). 31P{1H} NMR (δ,
CDCl3): 6.95 (s). Electrode potential: no response was ob-
served from -1.8 to 1.8 V.
1
3
Syn th esis of [Ru Cl(η6-p-cym en e)(P P h 2CtCC6H4CN)2]-
(P F6) (10). A 0.10 g sample of [(p-cymene)RuCl2(PPh2CtCC6H4-
CN)] (0.16 mmol) was stirred with 0.06 g (0.16 mmol) of TlPF6
and 0.05 g of PPh2CtCC6H4CN (0.16 mmol) in acetone. After
90 min the mixture was evaporated to dryness, treated with
CH2Cl2, and filtered through Celite. The resulting red solution
was evaporated to dryness and treated with diethyl ether,
affording 10 as an orange solid. Yield: 96.7%. Anal. Calcd for
corresponding to one C6F5 ring, coalesce at ca. 288
K
(∆Gq ) 51.95 kJ ‚mol-1), while the signals at -116.43 and
288
-123.00 coalesce at 298 K (∆Gq ) 52.2 kJ ‚mol-1). At the
298
highest temperature recorded (308 K), no signals due to o-F
have risen above the baseline. For 11b, the two signals due to
the o-F (as well as both of the signals due to m-F) broaden
and coalesce at ca. 268 K (258 K for m-F; ∆Gq
) 50.8
268
kJ ‚mol-1 for o-F, ∆Gq ) 50.7 kJ ‚mol-1 for m-F). At 293 K:
258
C
52ClF6H42N2P3Ru‚CH2Cl2: C, 56.67; H, 3.95; N, 2.49. Found:
C, 56.23; H, 3.91; N, 2.14. (The presence of CH2Cl2 has been
11a : the signals due to o-F are embedded in the baseline;
-160.78 (t, p-F); -161.95 (t, p-F); -164.4 (s br, m-F): -164.79
observed by 1H NMR spectroscopy.) ΛM: 133 Ω-1‚cm2‚mol-1
MS ES(+): m/z 893 [M - PF6]+ 16%; 682 [Ru(cym)2(PPh2-
CtCC6H4CN)]+ 100%. IR (cm-1): ν(CtN) 2228 (m); ν(CtC)
2176 (s); ν(PF6) 839 (vs); ν(Ru-Cl) 288 (w). 1H NMR (δ,
CDCl3): 7.85-7.06 (m, 28H, CH, Ph); 5.59, 5.46 (AA′BB′
system, J H-H ) 5.4, 4H, C6H4, p-cym); 2.75 (sept, J H-H ) 6.9,
.
3
(m, m-F). 11b: -119.76 (s br, J Pt-o-F ≈ 520, o-F); -163.82 (t,
p-F); -165.88 (m, m-F). 31P{1H} NMR (δ, CDCl3): 46.32 (s).
a
11b: 8.03 (s). Ep ) 1.203 V (irreversible).
Da ta for 12a . Yield: 76%. Anal. Calcd for C40Cl2F10H33
-
PPtRu: C, 43.61; H, 3.02. Found: C, 43.26; H, 3.08. MS ES-
(+): m/z 1151 [M + 2Na + 3H]+ 35% (sample ionizated with
Na+). IR (cm-1): ν(CtC) 1990 (m); ν(C6F5)X-sens 806 (m), 798
(m); ν(Ru-Cl) 308 (w), 229 (w). Complex 12a is not very soluble
in CDCl3, although soluble enough to record the 1H NMR
spectrum. The observed ratio for the equilibrium 12a /12b at
room temperature is 60:40 in CDCl3 and 30:70 in HDA. 1H
NMR (δ, CDCl3): 8.41, 7.96, 7.82, 7.51 (m, Ph; overlapped with
those corresponding to phenyl protons of 12b); ∼5.7 (br, C6H4,
p-cym. This signal is obscured by the corresponding signals of
12b); 5.46 (br), 5.21 (br), 4.60 (br) (C6H4, p-cym); 2.30 (sept,
J H-H ) 6.9, CH, iPr); 2.00 (s, CH3-C6H4); 1.18 (d, J H-H ) 6.9),
i
1H, CH, Pr); 1.98 (s, 3H, CH3-C6H4); 1.2 (d, J H-H ) 6.9, 6H,
CH3, Pr). 19F NMR (δ, CDCl3): -71.42 (d, J P-F ) 714.7, PF6).
i
31P{1H} NMR (δ, CDCl3): -144.15 (sept, J P-F ) 714.7, PF6).
31P{1H} NMR (δ, CDCl3): 3.31 (s). The 13C{1H} NMR spectrum
could not be obtained because it decomposes in solution.
Electrode potential: no response was observed from -1.8 to
1.8 V.
Syn th esis of [(η6-p-cym en e)ClRu (µ-Cl)(µ-P P h 2CtCR)-
P t(C6F 5)2] (Xa ) (R ) P h , X ) 11; R ) tBu , X ) 12; R ) Tol,
X ) 13; R ) C6H4CtCC6H5, X ) 14). Gen er a l P r oced u r e.
Solutions of [(η6-p-cymene)RuCl2(PPh2CtCR)] (R ) Ph 1, tBu
2, Tol 3, C6H4CtCC6H5 4) in CH2Cl2 (10 mL) were treated with
an equimolecular amount of [cis-Pt(C6F5)2(thf)2]. In each case,
the resulting solution was stirred for 10 min and evaporated
to dryness. Addition of diethyl ether yielded complexes 11a -
14a as red (11a , 13a ), salmon pink (12a ), and brown (14a )
solids. Although in the solid state only complexes Xa (X ) 11-
14) are present, in solution the NMR data indicate the
presence of an equilibrium between the isomers Xa and [(η6-
p-cymene)(PPh2CtCR)Ru(µ-Cl2)Pt(C6F5)2], Xb (X ) 11-14).
The following amounts of precursors were employed. For 11:
0.10 g (0.17 mmol) of 1 with 0.11 g of [cis-Pt(C6F5)2(thf)2]. For
12: 0.15 g (0.26 mmol) of 2 with 0.18 g of [cis-Pt(C6F5)2(thf)2].
For 13: 0.15 g (0.25 mmol) of 3 with 0.17 g of [cis-Pt(C6F5)2-
(thf)2]. For 14: 0.10 g (0.15 mmol) of 4 with 0.11 g of [cis-Pt-
(C6F5)2(thf)2].
i
1.16 (d, J H-H ) 9.0) (2 CH3, Pr); 0.82 (s, tBu). 12b: 5.73
(AA′BB′ system, J H-H ≈ 5, C6H4, p-cym; overlaps with the
signal corresponding to one C6H4 proton of 12a ); 2.65 (sept,
i
t
J H-H ) 6.7, CH, Pr); 1.87 (s, CH3-C6H4); 1.45 (s, Bu); 1.18
(d, J H-H ) 7.2, CH3, iPr). 13C{1H} NMR (δ, HDA): only signals
due to 12b can be assigned unequivocally; 133.5 (d, J C-P
2
)
4
11.17, o-C, Ph); 132.2 (d, J C-P ) 2.9, p-C, Ph); 131.8 (d,
1J C-P ) 56, i-C, Ph); 129.6 (d, 3J C-P ) 11.3, m-C, Ph); 124.3 (d,
2J C-P ) 12.2, Câ); 110.1 (d, J C-P ) 1.5, C4, p-cym); 100.4 (C1,
2
p-cym); 91.4 (d, J C-P ) 4.1); 90.3 (d, J C-P ) 4.8) (C2 and C3,
2
2
p-cym); 71.2 (J C-P ) 103, tentatively assigned to CR); 31.5 (C6,
p-cym); 30.5 (d, J C-P ) 1.4, C(CH3)3); 22.1 (C7, p-cym); 18.2
4
(C5, p-cym). 19F NMR (δ, HDA, 376.47 MHz): at 200 K the
ratio 12a /12b is ∼30:70; -116.87 (m), -117.54 (m), -121.19
(m), -122.28 (m) (1:1:1:1, o-F) (platinum satellites are observed

Ru/ Pt Heterobimetallic Complexes
Organometallics, Vol. 23, No. 18, 2004 4299
3
for some of the signals, but J Pt-o-F cannot be assigned);
J H-H ) 6.7, CH3, iPr). Upon lowering the temperature the 14a :
14b ratio increases to ca. 75:25 and the CH (C6H4) and methyl
(CH(CH3)2) resonances of p-cymene in 14a broaden, coalesce,
and finally resolve into four aromatic and two broad aliphatic
resonances, respectively (223 K C6H4: 5.81; 5.69; 5.26 and 4.74;
-161.37 (s br), -161.77 (s br) (1:1, p-F); ∼-164.3 (br, m-F,
this signal overlaps with the signal due to the p-F of 12b);
164.83 (m, m-F). 12b: -119.07 (d), -119.27 (d) (3J Pt-o-F cannot
be unequivocally assigned, o-F); -164.26 (s br, p-F); -166.42
(s br, m-F). For 12a , the signals at -116.87 and -122.28,
CH(CH3)2: 0.98 (br); 0.83 (br)). ∆Gq for CH(CH3)2 ≈ 53.9
263
corresponding to one C6F5 ring, coalesce at 290 K (∆Gq
≈
kJ ‚mol-1; ∆Gq for the CH signals located at 5.81 and 4.74
290
288
50.5 kJ ‚mol-1), while the signals at -117.54 and -121.19
ppm ≈ 54.5 KJ ‚mol-1
.
19F NMR (δ, CDCl3, 282.4 MHz): at
coalesce at ca. 318 K (ca. the highest temperature recorded)
238 K, the ratio 14a /14b is 75:25; -116.48 (d, 3J Pt-o-F ≈ 340),
(∆Gq ) 56.7 kJ ‚mol-1). For 12b, the two signals due to the
-117.05 (s br, J Pt-o-F ≈ 365), -120.68 (d, J Pt-o-F ≈ 365),
3
3
318
o-F coalesce at 270 K (∆Gq
) 54.3 kJ ‚mol-1). At 290 K:
-123.00 (d, J Pt-o-F ≈ 315) (1:1:1:1 o-F); -159.97 (t, p-F);
3
270
12a : only two broad signals (1:1) at -117.08 (3J Pt-o-F ≈ 365)
and -121.35 (3J Pt-o-F ≈ 400) are observed in the o-F region;
-162.92 (s br), -163.53 (s br) (1:1, p-F); -165.98 (m, 4 m-F).
-160.98 (t, p-F); -162.86 (m), -163.94 (m) (1:3 m-F). 14b:
3
3
-119.39 (d, J Pt-o-F ≈ 480), -120.31 (d, J Pt-o-F cannot be
determined) (o-F); -163.10 (t, p-F); -164.91 (m), -165.31 (m)
(m-F). For 14a , the signals at -117.05 and -123.00, corre-
3
12b: -119.13 (s br, J Pt-o-F ≈ 525, o-F); -165.80 (s br, p-F);
-167.60 (s br, m-F). 31P{1H} NMR (δ, HDA): 48.55 (s). 12b:
sponding to one C6F5 ring, coalesce at 288 K (∆Gq ) 50.6
288
7.51 (s). Ep ) 1.17 V (irreversible).
kJ ‚mol-1), while the signals at -116.48 and -120.68 coalesce
at 298 K (∆Gq298 ) 53.3 kJ ‚mol-1). At the highest temperature
recorded (308 K), no signals due to o-F have risen above the
baseline. For 14b, the two signals due to the o-F, as well as
both of the signals due to m-F, broaden and coalesce
(∆Gq ) 51.1 kJ ‚mol-1 for o-F; ∆Gq ) 50.4 kJ ‚mol-1 for
a
Da ta for 13a . Yield: 82%. Anal. Calcd for C43Cl2F10H31
PPtRu: C, 45.48; H, 2.75. Found: C, 45.14; H, 2.66. MS ES-
(+): m/z 1179 [M + 2Na - 3H]+ 5%; 571 [M - Pt(C6F5)2
-
-
Cl]+ 100% (sample ionizated with Na+). IR (cm-1): ν(CtC)
1987 (br); ν(C6F5)X-sens 808 (s), 798 (s); ν(Ru-Cl) 304 (w), 224
(w). In solution, the observed ratio for the equilibrium 13a /
13b at room temperature is 55:45 in CDCl3 and 30:70 in HDA.
1H NMR (δ, CDCl3): 8.18-6.92 (m, aromatics, Ph and Tol;
these signals overlap with the corresponding signals of 13b);
5.38 (s br), 5.2 (v br) (C6H4, p-cym); 2.40 (sept, J H-H ) 6.9,
268
258
m-F). At 293 K: 14a : ∼-117 (br, o-F) (The other signals due
to o-F are embedded in the baseline); -160.58 (t), -161.56 (t)
(p-F); ∼-164.2 (br), -164.43 (m) (m-F). 14b: -119.84 (s br,
3J Pt-o-F ≈ 530, o-F); -163.73 (t, p-F); -165.80 (m, m-F).
31P{1H} NMR (δ, CDCl3): 46.72 (s). 14b : 9.80 (s). Ep
1.208 V (irreversible).
)
a
i
CH, Pr); 2.19 (s, CH3, Tol); 1.94 (s, CH3-C6H4, p-cym); 0.98
Syn t h esis of [(η6-p -cym en e)(P P h 2CtCR )R u (µ-Cl)(µ-
P P h 2CtCR)P t(C6F 5)2](OTf) (R ) P h 15, Bu 16, Tol 17).
i
(d, J H-H ) 6.9, CH3, Pr). 13b : 5.81, 5.75 (AA′BB′ system,
t
J H-H ) 5.9, C6H4, p-cym); 2.67 (sept, J H-H ) 6.9, CH, iPr); 2.42
(s, CH3, Tol); 1.92 (s, CH3-C6H4, p-cym); 1.13 (d, J H-H ) 6.9,
Gen er al P r ocedu r e. [cis-Pt(C6F5)2(thf)2] was added to equimo-
lecular solutions of [(η6-p-cymene)RuCl(PPh2CtCR)2](OTf)
(R ) Ph 6, tBu 7, Tol 8) in CH2Cl2 (∼10 mL), and the mixtures
were stirred for 5 min, evaporated to dryness, and treated with
diethyl ether for 15 and 17 (or hexane for 16) to yield the
corresponding products as yellow solids. The following amounts
were employed: for 15 0.06 g (0.06 mmol) of 6 with 0.04 g of
[cis-Pt(C6F5)2(thf)2]; for 16 0.08 g (0.08 mmol) of 7 with 0.06 g
of [cis-Pt(C6F5)2(thf)2]; for 17 0.07 g (0.07 mmol) of 8 with
0.0462 g of [cis-Pt(C6F5)2(thf)2].
i
CH3, Pr). By lowering the temperature, the 13a :13b ratio
increases to ca. 80:20 and the CH (C6H4) and methyl (CH-
(CH3)2) resonances for 13a broaden and finally resolve into
four CH signals (223 K: 4.71 (d), 5.27, 5.67, 5.78) and two
doublets (0.95, J H-H ) 5.9; 0.83, J H-H ) 5.5), respectively.
∆Gq for Me ≈ 54.36 kJ ‚mol-1 and ∆Gq for the CH signals
263
288
located at 4.71 and 5.78 ppm ≈ 54.58 kJ ‚mol-1
.
19F NMR
(δ, CDCl3, 282.4 MHz): at 238 K, the ratio 13a /13b observed
3
is ca. 80:20: -116.40 (d, J Pt-o-F ≈ 360), -117.23 (s br,
3
3J Pt-o-F ≈ 395), -120.59 (d, J Pt-o-F ≈ 415), -122.87 (d,
Da ta for 15. Yield: 78%. Anal. Calcd for C63ClF13H44O3P2-
PtRuS‚CH2Cl2: C, 47.85; H, 2.89; S, 2.00. Found: C, 47.97;
H, 2.51; S, 1.99. ΛM: 133 Ω-1‚cm2‚mol-1. MS ES(+): m/z 1086
[M - OTf - PPh2CtCPh - H]+ 4%; 843 [RuCl(cym)(PPh2-
CtCPh)2]+ 100%; 709 [RuCl(PPh2CtCPh)2]+ 29%. IR (cm-1):
ν(CtC) 2168 (m); ν(µ-CtC) 1988 (m); ν(C6F5)X-sens 809 (m), 800
3J Pt-o-F ≈ 325) (1:1:1:1 o-F); -160.28 (t), -161.45 (t) (1:1 p-F);
-162.94 (m), -164.32 (m) (1:3 m-F). 13b: -119.25 (d), -120.35
(d) (3J Pt-o-F satellites cannot be determined, o-F); -163.20 (t,
p-F); -165.04 (m), -165.46 (m) (m-F). For 13a , the signals at
-117.23 and -122.87, corresponding to one C6F5 ring, coalesce
at 288 K (∆Gq288 ) 50.8 kJ ‚mol-1), while the signals at -116.40
1
(m); ν(Ru-Cl) 258 (w). H NMR (δ, CDCl3): 8.30, 7.94, 7.58,
and -120.59 coalesce at 298 K (∆Gq ) 53.3 kJ ‚mol-1). At
7.49, 7.35, 7.12, 7.02, 6.83, 6.64 (m, 30H, Ph); 5.91 (s br, 1H),
298
the highest temperature recorded (308 K), no signals due to
o-F have risen above the baseline. For 13b, the two signals
due to the o-F (as well as both of the signals due to m-F)
5.79 (m, 2H), 4.86 (d, J H-H ) 5.4, 1H) (C6H4, p-cym); 2.42 (m,
i
J H-H ) 6.6, 1H, CH, Pr); 2.24 (s, 3H, CH3-C6H4); 1.11 (d,
i
i
J H-H ) 6.6, 3H, CH3, Pr); 1.03 (d, J H-H ) 6.6, 3H, CH3, Pr).
broaden and coalesce at 268 K (258 K for the m-F; ∆Gq
)
19F NMR (δ, CDCl3, 233 K): -78.64 (s, 3F, OTf); -115.44 (d,
268
50.7 kJ ‚mol-1 for o-F; ∆Gq
) 50.8 kJ ‚mol-1). At 298 K:
3J Pt-o-F ) 420, 1 o-F); -117.25 (d, J Pt-o-F ) 355, 1 o-F);
3
258
3
3
13a : the signals due to o-F are embedded in the baseline;
-161.0 (t, p-F); -162.20 (t, p-F); -164.48 (br), -164.95 (m)
-120.65 (d, J Pt-o-F ) 415, 1 o-F); -123.45 (d, J Pt-o-F ) 295,
1 o-F); -158.09 (t, 1 p-F); -160.08 (t, 1 p-F); -162.16 (m, 1
m-F); -163.39 (m, 2 m-F); -163.90 (m, 1 m-F). Upon heating,
the exterior o-F signals broaden and, finally, coalesce at 303
3
(2:2 m-F). 13b: -119.73 (br, J Pt-o-F ) 518, o-F); -163.93 (t,
p-F); -165.97 (m, m-F). 31P{1H} NMR (δ, CDCl3): 46.04 (s).
a
K (∆Gq ) 52.6 kJ ‚mol-1), as well as two meta resonances
13b: 7.10 (s). Ep ) 1.126 V (irreversible).
303
located at -163.39 and -163.90 at ca. 268 K (∆Gq ) 52.4
Da ta for 14a . Yield: 90%. Anal. Calcd for C50Cl2F10H33
-
268
kJ ‚mol-1). At 293 K: -78.44 (s, 3F, OTf); -117.0 (v br, 1 o-F);
PPtRu‚1/2CH2Cl2: C, 47.97; H, 2.71. Found: C, 47.99; H, 2.17.
MS ES(+): m/z 657 [M - Pt(C6F5)2 - Cl]+ 100%. IR (cm-1):
ν(CtC) 2170 (m), 1965 (w); ν(C6F5)X-sens 812 (s), 801 (s);
ν(Ru-Cl) 266 (w). In solution, the observed ratio for the
equilibrium 14a /14b at room temperature is 52:48 in CDCl3
and ca. 25:75 in HDA. 1H NMR (δ, CDCl3): 8.19-7.32 (m,
aromatics, Ph and (4-CtCPh)C6H4; these signals overlap with
the corresponding signals of 14b); 5.40 (s br), ∼5.3 (v br) (C6H4,
3
3
-117.30 (d, J Pt-o-F ≈ 370, 1 o-F); -120.67 (d, J Pt-o-F ≈ 410,
1 o-F); -123.0 (v br, 1 o-F); -158.68 (t, 1 p-F); -160.75 (t, 1
p-F); -162.85 (m, 1 m-F); -163.86 (m, 1 m-F); -164.16 (m,
2 m-F). 31P{1H} NMR (δ, CDCl3): 51.55 (d, µ-P); 2.98 (d)
(2J P-P ) 53.0). Ep ) -0.950 V (quasi reversible); Ep
)
c
a
-0.445 V (irreversible).
Da ta for 16. Yield: 95%. Anal. Calcd for C59ClF13H52O3P2-
PtRuS: C, 47.83; H, 3.54; S, 2.16. Found: C, 47.81; H, 3.58;
S, 2.56. ΛM: 134 Ω-1‚cm2‚mol-1. MS ES(+): m/z 803 [RuCl-
(cym)(PPh2CtCtBu)2]+ 100%; 669 [RuCl(PPh2CtCtBu)2] 10%.
IR (cm-1): ν(CtC) 2203 (sh), 2165 (m); ν(µ-CtC) 1977 (w);
i
p-cym); 2.38 (sept, J H-H ) 6.7, CH, Pr); 1.94 (s, CH3-C6H4;
this signal coincides with the CH3-C6H4 signal of 14b); 0.99
i
(d, J H-H ) 6.7, CH3, Pr). 14b: 5.80 (s br, C6H4, p-cym); 2.61
(sept, J H-H ) 6.7, CH, iPr); 1.94 (s, CH3-C6H4); 1.10 (d,

4300 Organometallics, Vol. 23, No. 18, 2004
Berenguer et al.
ν(C6F5)X-sens 808 (s br); ν(Ru-Cl) 260 (w). 1H NMR (δ, CDCl3):
7.99, 7.68, 7.47, 7.36, 7.25, 7.18 (m, 20H, Ph); 5.91 (s br), 5.68
(d, J H-H ) 5.7), 5.29 (s br), 5.0 (d, J H-H ) 5.3) (4H, C6H4,
tion. Images were processed using the DENZO and SCALE-
PACK suite of programs,64 and the absorption correction was
performed using SORTAV.65 The structure of 12a ‚(acetone)
was solved by Patterson and Fourier methods using the
DIRDIF92 program,66 while the rest of the structures were
solved by direct methods (3) or the Patterson method (7, 17‚
2CHCl3) using the SHELXL-97 program.67 The four structures
were refined by full-matrix least squares on F2 with SHELXL-
97. All non-hydrogen atoms were assigned anisotropic dis-
placement parameters, and all hydrogen atoms were con-
strained to idealized geometries fixing isotropic displacement
parameters of 1.2 times the Uiso value of their attached carbon
for the phenyl and methine hydrogens and 1.5 for the methyl
groups. In the case of complex 17, one phenyl group (C(24)-
C(29)) presents a positional disorder, which could be refined
over two positions with partial occupancy factors of 0.50. The
absolute structure parameters for 7 and 12a ‚(acetone) are
-0.03(3) and 0.031(5), respectively. 12a ‚(acetone), which
crystallizes in the space group P212121, shows the enantio-
morphic S form in the crystallographic study presented in this
paper (Figure 2). Nevertheless, one study carried out with
another crystal chosen from the same crystalline sample has
shown the enantiomer R for complex 12a . The cation present
in complex 17 also possesses a chiral center in the ruthenium
atom, but in this case both enantiomers, R and S, are present
in the unit cell (Figure 6 shows the enantiomer R). Finally,
for complex 12a , the low quality of the crystals does not allow
the observation of reflections at high θ, and, also, two residual
peaks (1.59 and 1.44 e Å-3) close to the Pt atom were observed,
but with no chemical significance.
i
p-cym); 2.08 (m, 1H, CH, Pr); 2.00 (s, 3H, CH3-C6H4); 1.53
(s, 9H, tBu); 1.08 (d, J H-H ) 6.7, 3H, CH3, iPr); 0.98 (d, J H-H
)
6.7, 3H, CH3, iPr); 0.82 (s, 9H, tBu). 19F NMR (δ, CDCl3,
223 K): -78.68 (s, 3F, OTf); -115.11 (br, 1 o-F); -116.59 (br,
1 o-F); -121.60 (br, 1 o-F); -122.46 (br, 1 o-F) (3J Pt-o-F cannot
be assigned); -157.84 (br, 1 p-F); -159.03 (br, 1 p-F); -162.04
(br, 1 m-F); -162.72 (br, 3 m-F). Upon heating, the signals at
-115.11 and -116.59, as well as the signals at -121.60 and
-122.46, broaden and coalesce at ca. 253 K (∆Gq253 ) 47.1 and
48.3 kJ ‚mol-1, respectively). At 293 K: -78.41 (s, 3F, OTf);
3
3
-117.88 (d, J Pt-o-F ≈ 350, 2 o-F); -120.84 (d, J Pt-o-F ≈ 390,
2 o-F); -158.55 (t, 1 p-F); -159.64 (t, 1 p-F); -163.22 (m,
4 m-F). 31P{1H} NMR (δ, CDCl3): 36.51 (d, µ-P); 0.72 (d)
(2J P-P ) 51.3). Electrode potential: no response was observed
from -1.8 to 1.8 V.
Da ta for 17. Yield: 71%. Anal. Calcd for C65ClF13H48O3P2-
PtRuS: C, 50.38; H, 3.12; S, 2.07. Found: C, 49.98; H, 2.76;
S, 1.93. ΛM: 121 Ω-1‚cm2‚mol-1. MS ES(+): m/z 1401 [M -
OTf]+ 100%. IR (cm-1): ν(CtC) 2170 (m); ν(µ-CtC) 1972 (m);
1
ν(C6F5)X-sens 815 (m), 807 (m); ν(Ru-Cl) 270 (w). H NMR (δ,
CDCl3) 8.29, 7.91, 7.57, 7.40, 7.27, 6.97, 6.82, 6.63 (m, 28H,
aromatics, Ph and Tol); 5.88 (s br, 1H), 5.75 (m, 2H), 4.83 (d,
J H-H ) 5.3, 1H) (C6H4, p-cym); 2.45 (s, 3H, CH3, Tol); 2.40 (m,
1H, CH, iPr); 2.26 (s, 3H, CH3-C6H4), 2.24 (s, 3H, CH3-C6H4)
i
(Tol and p-cym); 1.10 (d, J H-H ) 6.7, 3H, CH3, Pr); 1.02 (d,
i
J H-H ) 6.6, 3H, CH3, Pr). 19F NMR (δ, CDCl3, 233 K): -78.65
3
(s, 3F, OTf); -115.52 (d, J Pt-o-F ≈ 420, 1 o-F); -117.35 (d,
3
3J Pt-o-F ≈ 360, 1 o-F); -120.64 (d, J Pt-o-F ≈ 410, 1 o-F);
-123.35 (d, 3J Pt-o-F ≈ 295, 1 o-F); -158.25 (t, 1 p-F); -160.24
(t, 1 p-F); -162.23 (m, 1 m-F); -163.53 (m, 2 m-F); -163.97
(m, 1 m-F). Upon heating, the exterior o-F signals broaden and,
finally, coalesce at 298 K (∆Gq298 ) 51.8 kJ ‚mol-1). On the same
line, two m-F signals located at -163.53 and -163.97 coalesce
at ca. 263 K (∆Gq263 ≈ 51.7 kJ ‚mol-1). At 293 K: -78.39 (s, 3F,
Ack n ow led gm en t. We wish to thank the Direccio´n
General de Investigacio´n, Spain, and the European
Regional Development Fund (Projects BQU2002-03997-
C02-01, 02, PGE-FEDER) and the Comunidad de La
Rioja (APCI-2002/8) for financial support and grants to
A.G. and M.B., respectively.
3
OTf); -116.0 (v br, 1 o-F); -117.30 (d, J Pt-o-F ≈ 365, 1 o-F);
-120.61 (d, 3J Pt-o-F ≈ 405, 1 o-F); -122.5 (v br, 1 o-F); -158.80
(t, 1 p-F); -160.92 (t, 1 p-F); -162.90 (m, 1 m-F); -163.91 (m,
1 m-F); -164.26 (m, 2 m-F). 31P{1H} NMR (δ, CDCl3): 51.38
Su p p or tin g In for m a tion Ava ila ble: Further details of
the structure determinations of 3, 7, 12a ‚(acetone), and 17‚
2CHCl3 in CIF format. This material is available free of charge
via the Internet at http://pubs.acs.org.
(d, µ-P); 2.72 (d) (2J P-P ) 53.0). Ep ) -1.016 V (quasi
c
a
reversible); Ep ) -0.502 V (irreversible).
X-r a y Cr ysta llogr a p h y. Table 1 reports details of the
structural analyses for all complexes. Orange (3, 7) or yellow
(17) crystals were obtained by slow diffusion of n-hexane into
a dichloromethane (3) or chloroform (7, 17) solution of each
compound at room temperature, while red crystals of 12a were
obtained, leaving an acetone solution of this complex to
evaporate at room temperature. For complex 12a one molecule
of acetone and for complex 17 two molecules of CHCl3 are
found, respectively, in the asymmetric unit. X-ray intensity
data were collected with a NONIUS kCCD area-detector
diffractometer, using graphite-monochromated Mo KR radia-
OM049676J
(64) Otwinowski, Z.; Minor, W. In Methods in Enzymology; Carter,
C. V., J r., Sweet, R. M., Eds.; Academic Press: New York, 1997; Vol.
276A, p 307.
(65) Blessing, R. H. Acta Crystallogr. 1995, A51, 33.
(66) Beursken, P. T.; Beursken, G.; Bosman, W. P.; de Gelder, R.;
Garc´ıa-Granda, S.; Gould, R. O.; Smith, J . M. M.; Smykalla, C. The
DIRDIF92 program system; Technical Report of the Crystallography
Laboratory: University of Nijmegen: The Netherlands, 1992.
(67) Sheldrick, G. M. SHELX-97, a program for the refinement of
crystal structures; University of Go¨ttingen: Germany, 1997.