C-H activation in phosphonium salts promoted by platinum(II) complexes

Article abstract of DOI:10.1021/om001034i

The reaction of PtCl₂(NCPh)₂ with the bis-phosphonium salts {[R₂PhPCH₂]₂C(O)}Cl₂ (R₂ = Ph₂, PhEt, Et₂) (1:1 molar ratio) in refluxing 2-methoxyethanol affords the C,C-orthometalated complexes [PtCl₂(C₆H₄-2-PR₂ C(H)C(O)CH₂PPhR₂)] (R₂ = Ph₂ 1a, PhEt 1b, Et₂ 1c). The reaction of PtCl₂ with the bis-phosphonium salt {[Ph₃PCH₂]₂C(O)} Cl₂ (1:1 molar ratio) gives {[Ph₃PCH₂]₂C(O)}[PtCl₄], 2, while treatment of PtCl₂ with the perchlorate salts {[R₂PhPCH₂]₂C(O)}(ClO₄)₂ (1:1 molar ratio) results in the formation of the cationic dinuclear orthometalated derivatives [Pt(μ-Cl)(C₆H₄-2-PR₂C(H)C(O)CH₂PP hR₂)]₂(ClO₄)₂ (R₂ = Ph₂ 3a, PhEt 3b, Et₂ 3c). The cycloplatination of the bis-phosphonium salts to give the C,C-orthometalated derivatives implies two C-H bond activation processes at two types of carbon atoms, one arylic and one alkylic. The reaction of PtCl₂(NCPh)₂ or PtCl₂ with the allylphosphonium salts [PhR₂PCH₂CH=CH₂]Cl (R₂ = Ph₂, Me₂) or [Ph₃PCH₂CH=CHMe]Cl (1:1 molar ratio) in refluxing 2-methoxyethanol gives the orthometalated vinyl-phosphonium derivatives [PtCl₂(C₆H₄-2-PR₂-η²- E-C(H)=C(H)CH₃)] (R₂ = Ph₂ 4a, Me₂ 4b) or [PtCl₂(C₆H₄-2-PPh₂-η² -E-C(H)=C(H)CH₂CH₃)], 7, respectively, while the reaction of PtCl₂ with [Ph₃PCH₂-CH=CH₂]ClO₄ (1:1 molar ratio) gives the η²-olefin-bonded derivative [Cl₃Pt(η²-CH₂=CH-CH₂ PPh₃)], 5. The reaction of [Ph₃PCH₂CH=CHPh]Cl with PtCl₂ (1:1 molar ratio, 2-methoxyethanol, reflux) gives an easily separable mixture of products: the η²-olefin-bonded [Cl₃Pt(η²-CHPh=CH-CH₂PPh₃)], 8, and the orthometalated [PtCl₂(C₆H₄-2-PPh₂-η² -E-C(H)=C(H)CH₂Ph)], 9, while the reaction of [Ph₃PCH₂CMe=CH₂]Cl with PtCl₂ (1:1 molar ratio) gives a mixture of the cycloplatinated [PtCl₂(C₆H₄-2-PPh₂-η² -C(H)-CMe₂)], 10, and the isomerized vinyl-phosphonium salt [Ph₃P-C(H)=CMe₂]Cl, 11. The synthesis of complexes 4, 7, 9, and 10 implies the activation of one C(aryl)-H bond (instead of the more active methylene group adjacent to the phosphonium unit P-CH₂) and the rearrangement of the allyl group into a vinyl group by 1,3-prototropic shift, this shift being produced in the absence of external base. The complexes 4a·CH₂Cl₂ and 8 have been characterized by X-ray diffraction methods.

Full text of DOI:10.1021/om001034i

1424
Organometallics 2001, 20, 1424-1436
C-H Activa tion in P h osp h on iu m Sa lts P r om oted by
P la tin u m (II) Com p lexes
Larry R. Falvello,† Susana Ferna´ndez,† Carmen Larraz,† Rosa Llusar,‡
Rafael Navarro,*,† and Esteban P. Urriolabeitia†
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-Consejo Superior de Investigaciones Cientı´ficas, E-50009 Zaragoza,
Spain, and Departament de Ciencies Experimentals, Campus Riu Sec, Universitat J aume I,
POB 224, 12071 Castello´, Spain
Received December 4, 2000
The reaction of PtCl2(NCPh)2 with the bis-phosphonium salts {[R2PhPCH2]2C(O)}Cl2 (R2
) Ph2, PhEt, Et2) (1:1 molar ratio) in refluxing 2-methoxyethanol affords the C,C-
orthometalated complexes [PtCl2(C6H4-2-PR2C(H)C(O)CH2PPhR2)] (R2 ) Ph2 1a , PhEt 1b,
Et2 1c). The reaction of PtCl2 with the bis-phosphonium salt {[Ph3PCH2]2C(O)}Cl2 (1:1 molar
ratio) gives {[Ph3PCH2]2C(O)}[PtCl4], 2, while treatment of PtCl2 with the perchlorate salts
{[R2PhPCH2]2C(O)}(ClO4)2 (1:1 molar ratio) results in the formation of the cationic dinuclear
orthometalated derivatives [Pt(µ-Cl)(C6H4-2-PR2C(H)C(O)CH2PPhR2)]2(ClO4)2 (R2 ) Ph2 3a ,
PhEt 3b, Et2 3c). The cycloplatination of the bis-phosphonium salts to give the C,C-
orthometalated derivatives implies two C-H bond activation processes at two types of carbon
atoms, one arylic and one alkylic. The reaction of PtCl2(NCPh)2 or PtCl2 with the allyl-
phosphonium salts [PhR2PCH2CHdCH2]Cl (R2 ) Ph2, Me2) or [Ph3PCH2CHdCHMe]Cl (1:1
molar ratio) in refluxing 2-methoxyethanol gives the orthometalated vinyl-phosphonium
derivatives [PtCl2(C6H4-2-PR2-η2-E-C(H)dC(H)CH3)] (R2 ) Ph2 4a , Me2 4b) or [PtCl2(C6H4-
2-PPh2-η2-E-C(H)dC(H)CH2CH3)], 7, respectively, while the reaction of PtCl2 with [Ph3PCH2-
CHdCH2]ClO4 (1:1 molar ratio) gives the η2-olefin-bonded derivative [Cl3Pt(η2-CH2dCH-
CH2PPh3)], 5. The reaction of [Ph3PCH2CHdCHPh]Cl with PtCl2 (1:1 molar ratio,
2-methoxyethanol, reflux) gives an easily separable mixture of products: the η2-olefin-bonded
[Cl3Pt(η2-CHPhdCH-CH2PPh3)], 8, and the orthometalated [PtCl2(C6H4-2-PPh2-η2-E-C(H)d
C(H)CH2Ph)], 9, while the reaction of [Ph3PCH2CMedCH2]Cl with PtCl2 (1:1 molar ratio)
gives a mixture of the cycloplatinated [PtCl2(C6H4-2-PPh2-η2-C(H)dCMe2)], 10, and the
isomerized vinyl-phosphonium salt [Ph3P-C(H)dCMe2]Cl, 11. The synthesis of complexes
4, 7, 9, and 10 implies the activation of one C(aryl)-H bond (instead of the more active
methylene group adjacent to the phosphonium unit P-CH2) and the rearrangement of the
allyl group into a vinyl group by 1,3-prototropic shift, this shift being produced in the absence
of external base. The complexes 4a ‚CH2Cl2 and 8 have been characterized by X-ray diffraction
methods.
In tr od u ction
ture3), because of its practical importance.4 We recently
reported the intramolecular rearrangement of the C,C-
chelating bis-ylide ligand [C(H)PPh3]2CO to the C,C-
orthometalated ligand [(C6H4-2-PPh2C(H)COCH2PPh3)],5a
using PdII complexes, as well as the synthesis of PtII
complexes with the orthometalated group [(C6H4-2-
PPh2C(H)COCH2PPh3)] through cycloplatination of the
phosphonium-ylide [Ph3PdC(H)C(O)CH2PPh3]ClO4.5b
The orthometalation of ylide ligands is a known reac-
tion, not only for the platinum group metals6 but also
in early transition metals such as Nb.7
As part of our ongoing work on systems derived from
ylide groups,8 we have explored the reactivity of some
simple compounds of PtII, such as PtCl2 itself or PtCl2-
(NCR)2 (R ) Me, Ph), toward stabilized bis-phospho-
nium salts [R2PhPCH2C(O)CH2PPhR2](X)2 (R ) Et, Ph;
The activation of C-H bonds induced by transition
metals is, at present, one of the most active fields of
research in organometallic chemistry, due to its impli-
cations in several fundamental steps in catalytic cycles,
in the functionalization of simple substrates, and in
other important chemical processes.1 PtII complexes
have been employed frequently to promote C-H bond
activation,2 and interest in this class of reaction is
growing continuously (as evidenced by the number of
contributions from this field appearing in the litera-
* Corresponding author. E-mail: rafanava@posta.unizar.es. Inter-
net: http://lrf1.unizar.es/∼navarro/c_Rafa.html.
† Universidad de Zaragoza-Consejo Superior de Investigaciones
Cient´ıficas.
‡ Universitat J aume I.
(1) (a) Ryabov, A. D. Chem. Rev. 1990, 90, 403. (b) Shilov, A. E.;
Shul’pin, G. B. Chem. Rev. 1997, 97, 2879. (c) Steenwinkel, P.; Gossage,
R. A.; van Koten, G. Chem. Eur. J . 1998, 4, 759. (d) Dyker, G. Angew.
Chem., Int. Ed. 1999, 38, 1698. (e) Rybtchinsky, B.; Milstein, D. Angew.
Chem., Int. Ed. 1999, 38, 870.
(2) Anderson, G. K. In Comprehensive Organometallic Chemistry II;
Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press:
Oxford, 1995; Vol. 9, pp 507-518, and references therein.
10.1021/om001034i CCC: $20.00 © 2001 American Chemical Society
Publication on Web 03/08/2001

C-H Activation in Phosphonium Salts
Organometallics, Vol. 20, No. 7, 2001 1425
X ) Cl, ClO4)9a-c and also toward several allyl-phos-
phonium salts [PhR2PCH2-C(R′)dC(H)(R′′)]X (R ) Me,
Ph; R′ ) H, Me; R′′ ) H, Me, Ph; X ) Cl, ClO4).9d,e In
the case of the bis-phosphonium salts, we have found
that the reaction occurs through two C-H bond
activationssthe transformation of one phosphonium
unit into an ylide group and an unexpectedly easy
cycloplatination reactionswhich result in the prepara-
tion of complexes containing the C,C-orthometalated
ligand [C6H4-2-PR2C(H)COCH2PPhR2]. However, in the
case of the allyl-phosphonium salts, we have found two
different behaviors: (i) simple η2-coordination of the
olefin moiety of the allyl group to the PtII center, or (ii)
orthometalation through C(aryl)-H bond activation and
isomerization of the allyl group into a vinyl group,
resulting in complexes containing the cycloplatinated
ligand [C6H4-2-PR2C(H)dC(R′)-CH2R′′], σ-bonded to the
PtII center through one aryl carbon atom and π-bonded
through the vinylic CdC double bond.
(NCPh)2 with [R2PhPCH2C(O)CH2PPhR2](Cl)2 (R ) Et
and/or Ph) (1:1 molar ratio, 2-methoxyethanol, reflux,
22 h) results in the formation of the C,C-orthometalated
derivatives [PtCl2(C6H4-2-PR2C(H)COCH2PPhR2)] (R2 )
Ph2 1a ; PhEt 1b; Et2 1c), characterized by elemental
analysis and mass spectroscopy (see eq 1 and Experi-
mental Section). The IR spectra of 1a -c show the
carbonyl absorption in the range 1641-1647 cm-1, in
the same region as that reported for the PdII homologue
[PdCl2(C6H4-2-PR2C(H)COCH2PPhR2)] (1636 cm-1).5a
1
The H NMR spectra of 1a and 1c show a single set of
Resu lts
resonances, in accord with the presence of only one
isomer. The methine proton [Pt]-C(H)P appears in the
range 4.0-4.5 ppm as a doublet of doublets, through
coupling with two P nuclei, and shows 195Pt satellites.
1. Rea ctivity of P tII Com p lexes tow a r d r-Sta bi-
lized Bis-p h osp h on iu m Sa lts. The treatment of PtCl2-
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Solans, X.; Font-Bard´ıa, M. Organometallics 2000, 19, 1384. (d)
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2
The value of the coupling constant J Pt-H is about 114-
119 Hz, typical for C-bonded ylides.6f The presence of
the CH2PPhR2 unit can also be inferred from the 1H
spectra, since these protons appear as the AB part of
an ABX spin sytem (X ) 31P). The 31P{1H} NMR spectra
of 1a and 1c show, as expected, two doublets corre-
sponding to the two inequivalent P atoms. The presence
of the orthometalated aryl group can be clearly seen
from the 13C{1H} NMR spectrum of 1a , since there
appears a resonance at 145.96 ppm, typical for ortho-
metalated carbon atoms5a and attributed to C1.
Each of the complexes 1a and 1c possesses only one
chiral center (the ylidic carbon) and is presumably
obtained as the racemic mixture of the two enantiomers
(RC and SC). The situation found in complex 1b is
somewhat complicated since two chiral centers are
present, the P atom in the orthometalated ring and the
ylide carbon, leading to two possible diastereoisomers.
In fact, two fractions have been obtained in the synthe-
sis of 1b, the first one insoluble in the alcoholic reaction
medium and the second one soluble and precipitated
with Et2O. The spectroscopic characterization of the first
fraction (see Experimental Section) shows that it con-
sists of a single product (1bR), while the second fraction
is a mixture of the two possible diastereoisomers (1bR/
1bâ) in 1:4 molar ratio, thus permitting their separate
characterization. Each diastereoisomer will be the ra-
cemic mixture of the two enantiomers (RPRC/SPSC or
RPSC/SPRC), since the reaction was performed in the
absence of chiral sources, and we would not expect any
enantioselective induction. To ascertain the relative
configurations of the neighboring chiral P and C atoms
(4) (a) J ia, C.; Piao, D.; Oyamada, J .; Lu, W.; Kitamura, T.; Fujiwara,
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(7) Antin˜olo, A.; Carrillo-Hermosilla, F.; Dı´ez-Barra, E.; Ferna´ndez-
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1
of the orthometalated ring, we have measured the H-
1H NOESY spectra of 1bR and that of the mixture (1bR/
1bâ). For compound 1bR, the NOESY spectrum does not
show NOE interactions between the ylidic proton Pt-
C(H) and the CH2 protons of the ethyl group bonded to
the P atom. However, in the case of the mixture (1bR/
1bâ) there is a clear NOE interaction between the
resonance at 4.25 ppm, attributed to the ylidic proton
of complex 1bâ, and the resonances at 3.30 and 3.08

1426 Organometallics, Vol. 20, No. 7, 2001
Falvello et al.
the carbonyl oxygen is available to act as a ligating
agent, displacing one NCPh ligand.
To shed light on all of these questions, we have
performed a control experiment by refluxing the bis-
phosphonium salt {[Ph3PCH2]2CO}Cl2 in 2-methoxy-
ethanol for 22 h. At the end of the reaction and after
evaporation of the solvent, a very small (but detectable)
amount of the ylide-phosphonium salt [Ph3PdC(H)-
COCH2PPh3]Cl, probably formed as a result of a spon-
taneous loss of HCl, was found in the NMR of the
residue. Thus, it seems plausible that this ylide-phos-
phonium salt [Ph3PdC(H)COCH2PPh3]Cl, formed dur-
ing the reaction, could interact with the PtII center by
displacement of one NCPh group and C-coordination.
The subsequent orthometalation of the C-bonded ylide
should not differ from those described for other thermal
C-H bond activations of ylides promoted by metal
complexes.6 A similar mechanism (formation of the
ylide, C-coordination, and C-H activation) was proposed
for the orthometalation of [To3PCH2(py-2)]Cl,6d except
that in that case the formation of the ylide was ac-
complished by an external base. Another interesting
observation on the synthesis of 1a -c is that the three
complexes can be obtained in satisfactory yields, show-
ing that the orthometalation proceeds regardless of the
number of alkyl groups attached to the P atom (0, 1, or
2). These results contrast with those reported by us5a
for the cyclopalladation of the bis-ylide complexes {Pd-
(µ-Cl)[C(H)PPhR2]2CO}2(ClO4)2, in which a decrease of
the cone angle of the phosphine PPhR2 promoted a
dramatic decrease in the conversion to the metalated
derivative. In this context, the differences between the
PdII and PtII complexes are clear. In the case of PdII
complexes, the C,C-coordinated bonding mode of the bis-
ylide (obtained by deprotonation of the bis-phosphonium
salt with acetate as external base) is stable, and this
bonding mode is still unknown in PtII derivatives.
Further heating of the Pd(bis-ylide) complexes results
in the formation of the orthometalated derivatives
(although not in all cases) by intramolecular rearrange-
ment. In the case of PtII orthometalated complexes, the
synthesis is accomplished in all cases in a single step
without addition of external base. Thus, the method
reported here expands the synthetic accessibility of
orthometalated compounds.
F igu r e 1. Structures of complexes 1bR and 1bâ.
ppm, attributed to a methylene group in the same
complex. It is very likely that this NOE interaction is
due to the relative proximity of the ylide proton and the
ethyl group bonded to the P atom in the ring (see Figure
1), since the other ethyl group (resonances at 2.99 and
2.85) is found in a position more distant from the ylidic
proton. A plausible arrangement, such as that depicted
in Figure 1b, in which the ylidic proton and the ethyl
group are in equatorial positions could explain the ob-
served interactions, since any other arrangement would
leave these groups farther apart. Moreover, it is sensible
to assume that the bulky group -C(O)CH2PPh2Et on
the ylidic carbon would adopt an axial position in order
to minimize steric repulsions with other groups present
in the molecule. This has already been observed in the
cyclopalladated complex [Pd(C6H4-2-PPh2-C(H)-C(O)-
CH2PPh3)(PPh3)(NCMe)]ClO4.5a This arrangement re-
sults in absolute configurations (SPRC/RPSC) for isomer
1bâ (Figure 1b) and hence (RPRC/SPSC) for isomer 1bR
(Figure 1a).
The synthesis of 1a -c starting from the bis-phospho-
nium salts is noteworthy from several different points
of view. Two C-H bond activations have occurred, one
in the “activated” -C(dO)-C(sp3)H2 group and the
other one in the C(aryl-sp2)-H moiety. Formally, two
dehydrohalogenations have occurred but involving two
different types of C-H bonds since, instead of a second
C-H activation in the remaining “activated” methylene
adjacent to the carbonyl group, reaction occurs at an
arylic C-H bond. Probably the different size of the
resulting metallacyclessfour versus five linksscould
account for this behavior, obtaining the more thermo-
dynamically stable five-membered ring. Moreover, in a
recent communication,5b we have reported difficulties
in obtaining PtII complexes with the bis-ylide C,C-
coordinated [LnPt{C(H)PPh3}2CO]0,n+, analogous to those
reported for PdII.5a,8
Moreover, as far as we know, there is only one
precedent reported in the literature for this rare double
C-H bond activation in phosphonium salts,6d and very
few examples of any double C-H bond activation
promoted by the same metal have been reported.3b
Another interesting fact is that the orthometalation of
the bis-phosphonium salts [R2PhPCH2C(O)CH2PPhR2]-
(Cl)2 occurs without the assistance of an external base,
while the orthometalation of [To3PCH2(py-2)]Cl6d (To )
ortho-tolyl, 2-Me-C6H4) occurs only in the presence of
Proton Sponge [1,8-bis(dimethylamino)naphthalene] or
Na2CO3. Moreover, it seemed to have been established
that the species containing the C-H bond to be acti-
vated should be coordinated to the metal center prior
to the activation step itself. In the present case, only
The role of the ancillary ligands in the platinum
starting material is significant. Thus, the reaction of
PtCl2 with {[Ph3PCH2]2CO}Cl2 (1:1 molar ratio, 2-meth-
oxyethanol, reflux) results in the formation of the ionic
derivative [Ph3PCH2COCH2PPh3][PtCl4], 2 (see eq 2).
This complex was characterized on the basis of its
elemental analysis, mass spectrum, and IR spectrum,
but no NMR data could be obtained due to its insolubil-
ity in all common organic solvents. The IR spectrum of
2 has the carbonyl absorption at 1723 cm-1, that is, at
almost the same frequency found for [Ph3PCH2COCH2-
PPh3](ClO4)2 (1722 cm-1).9a,b It also shows a strong
absorption at 318 cm-1, attributed to the Pt-Cl stretch,
and which appears very close to the frequency reported
for K2[PtCl4] (321 cm-1).10
Moreover, the role of the counterion in stabilizing the
bis-phosphonium salts is relevant. Thus, the reaction

C-H Activation in Phosphonium Salts
Organometallics, Vol. 20, No. 7, 2001 1427
Sch em e 1
of PtCl2 (or PtCl2L2; L ) NCPh or NCMe) with the
perchlorates {[PhR2PCH2]2CO}(ClO4)2 (1:1 molar ratio,
2-methoxyethanol, reflux) gives the dicationic complexes
[Pt(µ-Cl)(C6H4-2-PR2C(H)COCH2PPhR2)]2(ClO4)2 (R2 )
Ph2 3a ; PhEt 3b; Et2 3c) (see eq 3), characterized by
their elemental analyses and mass spectra (see Experi-
mental Section). In this case, the reaction proceeds
faster (0.5-4 h) than in the synthesis of complexes 1a -c
(22 h). The NMR spectra of complexes 3a and 3c show
two sets of resonances, revealing the presence of two
isomers. Due to the presence of two chiral centers in
each dinuclear derivative, two diastereoisomers (each
one as the mixture of two enantiomers) are expected,
(RR/ SS) and (RS/ SR). The resemblance of the NMR
spectra of 3a to those obtained for the palladium
analogue5a [Pd(µ-Cl)(C6H4-2-PPh2C(H)COCH2PPh3)]2-
(ClO4)2 allows us to propose a similar stereochemistry
for these compounds; that is, complexes 3a and 3c have
been obtained as mixtures of the two diastereoisomers
(RR/ SS) and (RS/ SR) and the dinuclear skeleton
adopts an anti arrangement of the orthometalated
fragments. The observed molar ratio of the diastereo-
isomers is 1.6:1 for 3a (major/minor) and 1:1 for 3c; we
have not attempted the elucidation of the absolute
configurations for each isomer.
With respect to complex 3b, we have observed a
behavior more or less similar to that described for 1b,
except that the number of expected diastereoisomers for
3b is 8 (16 enantiomers), assuming an anti arrangement
of the orthometalated rings. Two fractions were ob-
tained, the first one precipitated in the alcoholic medium
and the second one precipitated by addition of Et2O (see
Experimental Section). The first fraction corresponds to
the mixture of two compounds (1.5:1 molar ratio), and
the second one shows, in its 31P{1H}NMR spectrum,
eight different resonances corresponding to the P atom
in the ring C6H4-2-PPhEtC(H)Pt. Due to the complexity
of the mixture obtained, we have not attempted to
assign absolute configurations to the isomers obtained.
In summary, we have found a very easy method for
the synthesis of orthometalate-ylide complexes of PtII
starting from bis-phosphonium salts, thus avoiding the
preparation of the sometimes unstable ylides or bis-
ylides.
reactivity, and coordinated allyl-ylides are expected to
be obtained. The reactivity of allyl-ylides continues to
attract some interest,11 and some PdII complexes with
allyl-ylides have been synthesized,12 although no plati-
num complexes with allyl-ylides have been reported un-
til now. Because of all this, we have explored the reac-
tivity of PtII complexes toward allyl-phosphonium salts.
The reaction of PtCl2(NCPh)2 or PtCl2 with [Ph3P-
CH2CHdCH2]Cl (1:1 molar ratio) in refluxing 2-meth-
oxyethanol (22 h) results in the formation of the or-
thometalated vinyl-phosphonium derivative cis-[Cl2Pt-
(C6H4-2-PPh2-E-η2-C(H)dC(H)Me] (4a , see Experimen-
tal and Scheme 1). Compound 4a crystallizes from
CH2Cl2/Et2O as a solvate in the form of colorless prisms
and shows correct elemental analyses and mass spec-
trum. The IR spectrum shows clearly the cis disposition
of the two chloride ligands by the appearance of two
absorptions at 326 and 285 cm-1
.
1
The analysis of the H NMR spectrum of 4a provides
important structural information. Thus, the presence
of the orthometalated Pt-C6H4 group can be inferred
from the observation of four different resonances, well
spread in the frequency domain (8.11, 7.42, 7.24, and
7.17 ppm), one of them (H6, 8.11 ppm) showing 195Pt
satellites (3J Pt-H6 ) 42 Hz) and giving proof of the
metalation of one aryl ring of the PPh3 unit. Interest-
ingly, we have not observed a similar dispersion of the
arylic resonances, nor platinum satellites, in the closely
related complexes 1a -c or 3a -c. Going to high field, it
is clearly seen that the resonances attributed to the
starting allyl group have disappeared and that new
resonances attributed to the vinylic fragment E-PC-
(H)dC(H)Me have appeared. The olefinic protons appear
as an AB spin system coupled with other nuclei; the
MeC(H)d proton appears at 4.56 ppm as a doublet of
doublets by coupling with the other olefinic proton and
the P atom, and the dC(H)P proton appears at 4.66 ppm
as a complex multiplet, due to the additional coupling
with the P and CH3 nuclei. The methyl group appears
as a doublet at 1.84 ppm, flanked by 195Pt satellites. The
E-configuration of the alkenyl fragment can be inferred
from the observation of the value of the coupling
2. Rea ctivity of P tII Com p lexes tow a r d Sem ista -
bilized Allyl-p h osp h on iu m Sa lts. In the preceding
examples the presence of a carbonyl group adjacent to
a methylene group activated the latter, and we have
observed more or less easy dehydrohalogenations through
C-H bond activation, resulting in PtII-ylide complexes.
The substitution of the carbonyl group by an olefin
moiety (allyl-phosphonium salts), although it should
produce a decrease in the acidity of the methylenic
P-CH2 protons, would not promote dramatic changes in
3
constant J P-H ) 17.1 Hz for the resonance at 4.56 ppm,
indicating a mutual cis arrangement,13a thus implying
a trans disposition of the methyl group and the P atom.
(11) (a) Wang, Q.; El Khoury, M.; Schlosser, M. Chem. Eur. J . 2000,
6, 420. (b) Breitsameter, F.; Polborn, K.; Schmidpeter, A. Eur. J . Inorg.
Chem. 1998, 1907.
(12) (a) Hirai, M.-F.; Miyasaka, M.; Itoh, K.; Ishii, Y. J . Chem. Soc.,
Dalton Trans. 1979, 1200. (b) Hirai, M.-F.; Miyasaka, M.; Itoh, K.; Ishii,
Y. J . Organomet. Chem. 1979, 165, 391. (c) Hirai, M.-F.; Miyasaka,
M.; Itoh, K.; Ishii, Y. J . Organomet. Chem. 1978, 160, 25.
(10) Nakamoto, K. Infrared Spectra of Inorganic and Coordination
Compounds, 2nd ed.; Wiley and Sons: New York, 1970; p 115.

1428 Organometallics, Vol. 20, No. 7, 2001
Falvello et al.
This E-configuration seems to be preferred in substi-
tuted vinyl-phosphonium salts.13 The coordination of the
olefinic CdC double bond to the platinum atom is
evident from the presence of 195Pt satellites in the
methyl resonance and in that attributed to the C(H)Me
proton. The 31P{1H} NMR spectrum of 4a shows a
resonance at 25.84 ppm, flanked by platinum satellites
(3J Pt-P ) 48.6 Hz), downfield relative to the correspond-
ing resonance in the free allyl-phosphonium salt (21.20
ppm).
served. After removal of the Pt0, the complex [PtCl3(η2-
CH2dCH-CH2PPh3)], 5, can be obtained from the
alcohol solution in low yield (see Scheme 1). Complex 5
gives the correct elemental analysis and mass spectra
(the phosphonium cation and the trichloroplatinate
anion are the only species detected in the positive and
negative FAB spectrum, respectively). The IR spectrum
of 5 shows absorptions corresponding to the Pt-Cl
stretch, which are very similar to those observed in
K[PtCl3(C2H4)], and does not show absorptions corre-
-
The presence of the orthometalated ligand and the
coordination of the generated vinylic unit to the plati-
num center can also be inferred from the APT 13C{1H}
NMR spectrum of 4a (see Experimental Section). Six
separate resonances (two with negative phase and four
with positive phase) in the range 150-120 ppm can be
attributed to the C6H4 fragment. Moreover, this spec-
trum shows resonances corresponding to two inequiva-
lent Ph groups, since in this molecule the molecular
plane is not a plane of symmetry. The Câ carbon atom
[dC(H)Me] appears as a singlet at 81.53 ppm, with Pt
satellites (1J Pt-C ) 223.2 Hz), and the CR carbon atom
sponding to the ClO4 group.
1
The H NMR spectrum of 5 does not show signals in
the aromatic region other than those attributed to the
Ph groups and shows the resonances corresponding to
the allyl moiety shifted to high field (range 4.77-4.00
ppm) with respect to the corresponding resonances in
the free allyl-phosphonium (range 5.61-5.17 ppm), as
expected for the η2-coordination of the CdC double bond.
Moreover, the relative intensity of the aromatic and
allylic resonances is 15:5, showing that in this case no
orthometalation has occurred. The 31P{1H} NMR spec-
trum of 5 shows a single signal at 18.34 ppm with
platinum satellites (J Pt-P ) 156.1 Hz). In contrast to
that observed in 4a , this resonance appears shifted to
high field with respect to the resonance of the free
phosphonium (21.20 ppm). The η2-coordination of the
allyl group can also be inferred from the 13C{1H} NMR
spectrum, since the Câ carbon appears at 68.95 ppm
(1J Pt-C ) 217 Hz) and the Cγ carbon at 67.52 ppm (1J Pt-C
) 193 Hz). Both signals show platinum satellites and
are shifted to high field with respect to the correspond-
ing values in the free allyl-phosphonium (Câ ) 123.12
ppm; Cγ ) 126.09 ppm). In accord with the structure
(see Scheme 1), signals corresponding to the presence
of only one type of Ph group are observed, and the PCH2
moiety remains unaltered, as can be deduced from the
position of the resonance (27.35 ppm) and its shape
[dC(H)P] appears as a doublet at 57.91 ppm (1J P-C
)
77.8 Hz), also showing Pt satellites (1J Pt-C ) 244.6 Hz).
These two resonances are shifted to high field by more
than 52 ppm with respect to the corresponding reso-
nances in the free vinyl phosphonium 6 (see below and
Experimental Section), and similar upfield shifts have
been reported in the coordination of ethylene, for
instance in the Zeise’s salt K[Cl3Pt(C2H4)].14 Finally, the
methyl group appears at 21.61 ppm as a doublet.
Further characterization of complex 4a is provided by
its X-ray structure (see below).
The allyl-phosphonium salts [PhMe2PCH2CHdCH2]Br
and [Ph3PCH2CHdCHMe]Br behave similarly toward
PtCl2 in refluxing 2-methoxyethanol. Thus, the corre-
sponding complexes cis-[Cl2Pt(C6H4-2-PMe2-E-η2-
C(H)dC(H)Me] (4b, very insoluble in most common
organic solvents) and cis-[Cl2Pt(C6H4-2-PPh2-E-η2-
C(H)dC(H)Et] (7) can be isolated and characterized
similarly to 4a (see Scheme 1 and eq 4).
1
(doublet, J P-C ) 48 Hz).
The solvent used in the reaction also exerts a consid-
erable influence on the synthesis of complexes of type
4 or 5. Thus, the reaction of [Ph3P-CH2CHdCH2]Cl
with PtCl2 (1:1 molar ratio) in refluxing toluene for only
1 h affords complex 5 in good yields (see Experimental
Section and Scheme 1). When the reaction time in
refluxing toluene is prolonged to 22 h, complex 5 is the
only species detected in the reaction mixture. However,
if complex 5 (isolated) is dissolved in 2-methoxyethanol
and this solution is refluxed for 22 h, complex 4a can
be obtained, although in lower yields than in the
procedure reported above.
However, the presence of different counterions in the
starting allyl-phosphonium salt gives different behav-
iors, as has already been observed in complexes 1a -c
and 3a -c. Thus, in the reaction of [Ph3PCH2CHdCH2]-
ClO4 with PtCl2 (1:1 molar ratio) in refluxing 2-meth-
oxyethanol (22 h) extensive decomposition can be ob-
The synthesis of the orthometalated vinyl-phospho-
nium complexes 4a and 4b starting from allyl-phospho-
nium salts implies, formally, a dehydrohalogenation by
C-H activation, but this C-H activation is produced
in one aryl ring of the PPh3 (or PPhMe2) unit, instead
of the more “expected” position, namely, the CR of the
allyl group. Moreover, the allyl group CH2-CHdCH2
undergoes isomerization, giving the methyl-vinyl group
-CHdCH-CH3, probably through a 1,3-prototropic
shift, and the vinylic moiety is η2-coordinated to the PtII
center. These facts constitute a clear difference with
respect to the reactivity of PdII compounds toward allyl-
phosphonium salts, since η3-allyl-phosphonium deriva-
tives of PdII have been reported12 (through deprotona-
(13) (a) Huang, C.-C.; Duan, J .-P.; Wu, M.-Y.; Liao, F.-L.; Wang,
S.-L.; Cheng, C.-H. Organometallics 1998, 17, 676. (b) Duan, J .-P.; Liao,
F.-L.; Wang, S.-L.; Cheng, C.-H. Organometallics 1997, 16, 3934. (c)
Rybin, L. V.; Petrovskaya, E. A.; Rubinskaya, M. I.; Kuz’mina, L. G.;
Struchkov, Y. T.; Kaverin, V. V.; Koneva, N. Y. J . Organomet. Chem.
1985, 288, 119. (d) Scordia, H.; Kergoat, R.; Kubicki, M. M.; Guerchais,
J . E.; L’Haridon, P. Organometallics 1983, 2, 1681. (e) Chin, C. S.; Lee,
M.; Oh, M.; Won, G.; Kim, M.; Park, Y. J . Organometallics 2000, 19,
1572. (f) Arisawa, M.; Yamaguchi, M. J . Am. Chem. Soc. 2000, 122,
2387. (g) Reynolds, K. A.; Dopico, P. G.; Brody, M. S.; Finn, M. G. J .
Org. Chem. 1997, 62, 2564.
(14) Mann, B. E.; Taylor, B. F. 13C NMR Data for Organometallic
Compounds; Academic Press: London, 1981; pp 192-197.

C-H Activation in Phosphonium Salts
Organometallics, Vol. 20, No. 7, 2001 1429
tion at CR by external base), and they are stable. The
isomerization of allyl-phosphonium derivatives into the
vinylic species was known several years ago.15 Thus, the
first plausible hypothesis one can imagine is that the
reaction occurs in two steps: The first is the generation
of the vinyl-phosphonium from the allylic salt, which
makes C-H activation at CR more difficult; the second
step is the orthometalation of the resulting vinyl-
phosphonium salt, which should not differ from those
described for other thermal C-H bond activations of
ylides.6
F igu r e 2. Proposed intermediates in the orthometalation
of allyl-phosphonium salts.
that the reaction should begin by direct interaction of
the allyl moiety with the PtII center. Two possibilities
can be envisaged: a structure similar to complex 5 or,
better, a platinum-ylide complex such as that repre-
sented in Figure 2, structure A, obtained by dehydro-
halogenation of the phosphonium salt at CR. Since it has
been proved that under our reaction conditions the
allyl-vinyl isomerization takes place, and that this
isomerization proceeds via ylide formation, it seems
reasonable to assume that, in the presence of the metal,
the ylide generated could coordinate to the platinum
center. We have represented this coordination as η3-
allyl-phosphonium by analogy with similar known pal-
ladium complexes.12 Once the ylide is coordinated, the
carbon-hydrogen activation step should occur, pro-
moted by the metal through either an oxidative addition
(intermediate B, Figure 2), an electrophilic substitution
(intermediate C, Figure 2), or a multicentered pathway,
since it has been reported1a that all of these mechanisms
could operate in C-H activation processes promoted by
platinum complexes. Finally, the hydrogen liberated by
the C-H activation is captured by Cγ of the allyl unit,
which thus becomes a vinylic moiety, giving the ortho-
metalated-vinyl derivatives.
However, some experimental facts militate against
this proposal. First, the known allyl-vinyl isomerization
always requires the presence of base,15 since the reac-
tion proceeds via ylide and the ylide is generated by
deprotonation with base, even in catalytic amounts.15a
To confirm that the allyl-vinyl isomerization really
occurs under our reaction conditions, we have refluxed
[Ph3P-CH2CHdCH2]X (X ) Br, Cl) in 2-methoxyetha-
nol for 22 h, in the absence of base. To our surprise,
this yielded (after workup) a white solid whose spec-
troscopic parameters are identical to those reported in
the literature for E-[Ph3PCHdCH-CH3]X,15a,b 6 (see
Experimental Section and Scheme 1). The same behav-
ior was observed when the allyl-phosphonium salt
[Ph3P-CH2C(Me)dCH2]Cl was refluxed in 2-methoxy-
ethanol; that is, the vinyl-phosphonium salt [Ph3P-
CHdCMe2]Cl was obtained in good yield (see below,
compounds 10 and 11). However, when the allyl-
phosphonium salts [Ph3P-CH2CHdCH-R]Cl (R ) Me,
Ph, employed in the synthesis of the orthometalated
complexes 7 and 9; see below) were treated in the same
fashion (2-methoxyethanol, reflux, 22 h), the starting
salts were recovered in quantitative yield. Nevertheless,
and although the isomerization occurs in some cases
under our reaction conditions, another factor mitigates
against the proposed mechanism. When the vinyl-
phosphonium salts E-[Ph3PCHdCH-CH3]X, 6, and
[Ph3P-CHdCMe2]Cl, 11, were refluxed in 2-methoxy-
ethanol with PtCl2 or PtCl2(NCR)2 (R ) Me, Ph, 1:1
molar ratio), the orthometalation reaction did not take
place, and the starting products were always recovered,
even after longer refluxing periods (48 h or more).
The reactivity of PtCl2 with other allyl-phosphonium
salts is similar to that described in the synthesis of 4a ,
4b, 5, and 7. Thus, PtCl2 reacts with [Ph3P-CH2-CHd
CH(Ph)]Cl in refluxing 2-methoxyethanol to give two
different, and easily separable, products. The first
product precipitates from the alcoholic medium as a
greenish powder. Recrystallization from CH2Cl2/Et2O
gives a deep yellow solid characterized as [PtCl3(η2-
PhCHdCH-CH2PPh3)], 8 (see eq 5). Slow crystalliza-
These two factss(i) the nonisomerization of the Cγ-
substituted allyl-phosphonium salts [Ph3P-CH2CHd
CH-R]Cl (R ) Me, Ph) and (ii) the lack of reactivity of
the isomerized vinyl-phosphonium salts E-[Ph3PCHd
CH-CH3]Cl, 6, and [Ph3P-CHdCMe2]Cl, 11, with PtII
complexesssuggest that the mechanism operating in
this reaction must be different from that proposed and
also suggest that the isomerization step should occur
after, and probably as a consequence of, the orthometa-
lation.
Once the notion of direct orthometalation of the vinyl-
phosphonium salts has been discarded, it seems clear
tion by Et2O vapor diffusion into a CH2Cl2 solution of 8
gives yellow crystals adequate for X-ray purposes (see
below). Complex 8 gives correct elemental analysis and
mass spectra (positive and negative FAB), and its IR
spectrum shows absorptions attributed to the Pt-Cl
stretch at 330, 327, and 312 cm-1, very similar to those
observed in 5 and in K[PtCl3(C2H4)].
(15) (a) Keough, P. T.; Grayson, M. J . Org. Chem. 1964, 29, 631. (b)
Seyferth, D.; Fogel, J . J . Organomet. Chem. 1966, 6, 205. (c) Schweizer,
E. E.; Shaffer, E. T.; Hughes, C. T.; Berninger, C. J . J . Org. Chem.
1966, 31, 2907. (d) Vedejs, E.; Bershas, J . P.; Fuchs, P. L. J . Org. Chem.
1973, 38, 3625. (e) Corey, E. J .; Erickson, B. W. J . Org. Chem. 1974,
39, 821. (f) Kim, S.; Kim, Y. C. Tetrahedron Lett. 1990, 31, 2901. (g)
Shen, Y.; Wang, T. Tetrahedron Lett. 1990, 31, 543. (h) Shen, Y.; Wang,
T. Tetrahedron Lett. 1990, 31, 3161. (i) Kim, S.; Kim, Y. C. Synlett
1990, 115. (j) Hatanaka, M.; Himeda, Y.; Ueda, I. J . Chem. Soc., Chem.
Commun. 1990, 526. (k) Shen, Y.; Wang, T. Tetrahedron Lett. 1991,
32, 4353.
The presence of the η2-coordinated phosphonium can
1
be inferred from the NMR spectral data. The H NMR
spectrum shows, in addition to the expected aromatic
signals, four different resonances corresponding to the

1430 Organometallics, Vol. 20, No. 7, 2001
Falvello et al.
four inequivalent protons of the -CH2-CHdCH- unit.
The two olefinic protons appear at 6.06 (with 195Pt
satellites) and 5.29 ppm, and the two diastereotopic
PCH2 protons appear at 4.43 and 4.10 ppm as the AB
part of an ABMX spin system (M ) 31P; X ) 1HCâ
olefinic), this fact reflecting clearly the η2-coordination
of the olefin. The 13C{1H} NMR spectrum also reflects
the η2-coordination of the olefin, since the resonances
attributed to the olefinic carbons Câ and Cγ show 195Pt
satellites (signal at 87.83 ppm) and are shifted downfield
(87.83 and 61.52 ppm) with respect to the corresponding
resonances in the free phosphonium (140.05 and 113.74
ppm). The 31P{1H} NMR spectrum shows a singlet
resonance at 18.37 ppm, with platinum satellites, and
it is shifted upfield with respect to the free phosphonium
(21.67 ppm), similar to what is observed for 5.
carbon atom Cγ has two substituents, for instance
[Ph3P-CH2-CHdCMe2]+, there is a complete lack of
reactivity toward the platinum complexes PtCl2(NCR)2
(R ) Me, Ph) or toward PtCl2 under the same experi-
mental conditions (2-methoxyethanol, reflux), and the
phosphonium salt is recovered at the end of the reaction
in almost quantitative yields. The same behavior was
observed when cyclic allyl-phosphonium salts were
employed, such as [(2-cyclohexenyl)triphenylphospho-
nium]bromide. However, if the substituent is located at
the Câ carbon atom, new complexes can be obtained,
although with some difficulties.
The reaction of [Ph3P-CH2-C(Me)dCH2]Cl with
PtCl2 (1:1 molar ratio) in refluxing 2-methoxyethanol
(22 h) gives a white solid after workup. The spectro-
scopic parameters of this solid show that it is actually
a mixture of the expected orthometalated derivative [Pt-
(C6H4-2-PPh2-η2-C(H)dCMe2)Cl2], 10, and the corre-
sponding vinyl-phosphonium salt [Ph3PC(H)dCMe2]Cl,
11 (see Experimental Section and eq 6). Exhaustive
The second product obtained in this reaction is soluble
in the alcohol medium. After workup (see Experimental
Section) a white crystalline solid was obtained, which
was characterized as the orthometalated [Pt(C6H4-2-
PPh2-η2-E-C(H)dC(H)CH2Ph)Cl2] 9 (see eq 5). Complex
9 gives the correct elemental analysis and mass spec-
trum. The IR spectrum shows two absorptions at 323
and 278 cm-1 corresponding to the Pt-Cl stretch, in
keeping with the presence of the cis-Cl2Pt moiety. The
spectroscopic characterization of 9 (see Experimental
Section) yields the same key features as those described
for 4a , 4b, and 7. The 1H NMR spectrum shows the
resonance attributed to the proton ortho to the cyclom-
etalation position (H6) at 8.18 ppm as a doublet of
washing of this solid with water in order to separate
the soluble phosphonium salt results in the decomposi-
tion of the platinum derivative, and after workup, only
11 is obtained. Attempts to recrystallize this mixture
always led to other mixtures with different molar ratios,
but never to pure products. Finally, attempts to separate
the mixture by column chromatography also led to
mixtures or to the decomposition of the organometallic
product 10. Thus, although it is possible to obtain a
complete spectroscopic characterization of both com-
pounds (see Experimental Section), satisfactory elemen-
tal analytical data and mass spectra could only be
obtained for the phosphonium salt 11.
doublets of doublets with platinum satellites (3J Pt-H6
)
37.8 Hz). The olefinic protons (HCR and HCâ) appear at
4.68 and 4.56 ppm as a split AB spin system, due to
the coupling with the P atom and with the diaste-
reotopic methylene protons of the benzyl group (CγH2-
Ph). In turn, these methylenic protons appear at 3.76
and 3.67 ppm, also as a coupled AB spin system (coupled
to HCâ). The 31P{1H} NMR spectrum shows a singlet
resonance at 26.79 ppm with platinum satellites (3J Pt-P
) 35.6 Hz). This resonance is shifted downfield with
respect to its position in the starting allyl-phosphonium
(21.67 ppm), similar to what was observed for 4a , 4b,
and 7. Finally, the 13C{1H} NMR spectrum of 9 shows
the expected resonances in accord with the proposed
structure.
The spectroscopic characterization of 10 clearly shows
the presence of the orthometalated vinyl-phosphonium
1
group. The H NMR shows the presence of resonances
attributed to the cycloplatinated C6H4 ring, the HCR
2
It is worth noting that complexes 5 and 8 contain the
allyl-phosphonium η2-coordinated, obviously nonisomer-
ized, but complexes 4a and 9 contain the isomerized and
orthometalated vinyl-phosphonium; that is, the coordi-
nation alone does not imply isomerization, but ortho-
metalation always implies isomerization. All attempts
simply to coordinate the vinyl-phosphonium salts (pro-
cesses similar to those described for 5 and 8) did not
result in the expected η2-coordination, and the starting
vinyl salts were recovered.
proton (4.63 ppm, J Pt-H ) 68.7 Hz), and two different
methyl groups (2.02 and 1.28 ppm), both with platinum
satellites (36.0 and 51.6 Hz, respectively). The 31P{1H}
NMR shows a resonance at 23.35 ppm with platinum
satellites (3J Pt-P ) 45.1 Hz), shifted downfield with
respect to the starting allyl derivative (20.33 ppm) and
also with respect to the corresponding free vinyl-phos-
phonium 11 (11.38 ppm). The 13C{1H} NMR spectrum
shows the expected upfield shifts for the CR and Câ
carbons on going from 11 to 10 due to the η2-coordina-
tion (CR, 103.13 ppm in 11 to 58.56 ppm in 10; Câ, 172.62
ppm in 11 to 101.36 ppm in 10) and also shows the pres-
ence of the two methyl groups (33.08 and 28.35 ppm).
3. X-r a y Cr ysta l Str u ctu r es. A drawing of the
organometallic compound 4a is shown in Figure 3,
relevant crystallographic parameters are shown in
Table 1, and selected bond distances and angles are
collected in Table 2. The platinum atom is bonded to
two mutually cis chlorine atoms, to the ortho carbon
From the observed reactivity in the synthesis of
complexes 4a (starting from [Ph3P-CH2-CHdCH2]+),
7 (starting from [Ph3P-CH2-CHdCHMe]+), and 9
(starting from [Ph3P-CH2-CHdCHPh]+), it seems that
the introduction of different substituents at Cγ does not
have any influence over the orthometalation reaction,
since in all cases the cycloplatinated derivatives can be
obtained. We have therefore also examined the influence
of multiple substituent on the allyl group. When the

C-H Activation in Phosphonium Salts
Organometallics, Vol. 20, No. 7, 2001 1431
Ta ble 2. Selected Bon d Len gth s [Å] a n d An gles
[d eg] for 4a ‚CH2Cl2.
Pt(1)-C(12)
Pt(1)-C(20)
Pt(1)-Cl(1)
P(1)-C(7)
P(1)-C(13)
C(7)-C(12)
C(9)-C(10)
C(11)-C(12)
C(20)-C(21)
1.997(9)
2.161(9)
2.394(2)
1.772(9)
1.797(9)
1.413(12)
1.373(15)
1.404(12)
1.516(12)
Pt(1)-C(19)
Pt(1)-Cl(2)
P(1)-C(19)
P(1)-C(1)
2.108(8)
2.291(3)
1.769(8)
1.787(9)
1.391(12)
1.387(14)
1.389(14)
1.395(12)
C(7)-C(8)
C(8)-C(9)
C(10)-C(11)
C(19)-C(20)
C(12)-Pt(1)-C(19)
C(19)-Pt(1)-C(20)
87.7(3) C(12)-Pt(1)-C(20)
38.1(3) C(12)-Pt(1)-Cl(2)
87.3(4)
90.8(3)
154.5(3)
91.4(2)
C(19)-Pt(1)-Cl(2) 167.2(2) C(20)-Pt(1)-Cl(2)
C(12)-Pt(1)-Cl(1) 175.2(2) C(19)-Pt(1)-Cl(1)
C(20)-Pt(1)-Cl(1)
C(19)-P(1)-C(7)
C(7)-P(1)-C(1)
C(7)-P(1)-C(13)
95.0(3) Cl(2)-Pt(1)-Cl(1)
103.1(4) C(19)-P(1)-C(1)
112.8(4) C(19)-P(1)-C(13)
111.2(4) C(1)-P(1)-C(13)
89.04(10)
109.3(4)
112.9(4)
107.6(4)
73.0(5)
C(20)-C(19)-P(1) 121.2(7) C(20)-C(19)-Pt(1)
P(1)-C(19)-Pt(1)
C(19)-C(20)-Pt(1)
C(7)-C(12)-Pt(1)
104.8(4) C(19)-C(20)-C(21) 123.5(8)
68.9(5) C(21)-C(20)-Pt(1) 115.3(6)
118.2(6) C(11)-C(12)-Pt(1) 125.9(7)
F igu r e 3. Thermal ellipsoid plot of [Pt(C6H4-2-PPh2-E-
η2-C(H)dC(H)Me)Cl2], 4a . Non-hydrogen atoms are drawn
at the 50% probability level.
olefins have a weak trans influence,18 and compound 4a
could be a good example. The Pt-Caryl bond distance
[Pt(1)-C(12) ) 1.997(9) Å] is similar, within experi-
mental error, to those found in other orthometalated
ylide complexes.6a,e The bond distances Pt-Cvinyl are
similar, within experimental error [Pt(1)-C(19) ) 2.108-
(8) Å and Pt(1)-C(20) ) 2.161(9) Å] and fall in the usual
range of distances found in η2-coordinated olefins.16,19
The environment around the P atom is tetrahedral, and
all P-C bond distances are similar within experimental
error. The vinylic CdC bond distance [C(19)-C(20) )
1.395(12) Å] is longer than that expected for a CdC
double bond with trans substituents [1.312(11) Å],20 due
to the coordination to the Pt atom, and the C-CH3 bond
distance [C(20)-C(21) ) 1.516(12) Å] is typical for a
C-C single bond.20 The olefin is almost perpendicular
to the coordination plane, as the dihedral angle between
Pt1-C20-C19 and Pt1-C12-Cl2-Cl1 is 86.2(4)°. In
addition, the olefin unit, including substituents, deviates
from planarity, as can be seen from the torsion angle
P1-C19-C20-C21, which is 155.6(7)°.
A drawing of the organometallic compound 8 is shown
in Figure 4, relevant crystallographic parameters are
listed in Table 1, and selected bond distances and angles
are collected in Table 3. The platinum atom is sur-
rounded by three chlorine atoms and by the trans-
cinnamyl-triphenylphosphonium cation, which is coor-
dinated through the CdC double bond. A pair of trans
chlorine atoms are disordered, with populations of 95%/
5% for the disordered congeners. The two sets of
positions correspond to different orientations of the
olefin, which has free rotation with respect to the PtCl3
unit. The dihedral angle between the planes Pt-Cl1-
Cl2-Cl3 and Pt-C2-C3 is 74.70(12)°, and that between
Pt-C2-C3 and Pt-Cl1′-Cl2-Cl3′ is 46.8(3)°. The Pt-
Cl bond distances [Pt(1)-Cl(1) 2.3220(7), Pt(1)-Cl(2) )
Ta ble 1. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
for 4a ‚CH2Cl2 a n d 8
4a ‚CH2Cl2
8
formula
mol wt
data collecn T, K
cryst syst
space group
a, Å
C
22H21Cl4PPt
C27H24Cl3PPt
680.87
298(2)
monoclinic
P21/n
10.1058(9)
14.9236(13)
17.1015(14)
90.517(2)
2579.1(4)
4
653.29
300(2)
monoclinic
P21/c
12.5634(10)
11.4472(9)
16.6823(11)
102.882(6)
2338.8(3)
4
b, Å
c, Å
â, deg
V, Å3
Z
D
calc Mg m-3
1.849
6.531
1248
1.754
5.827
1320
µ(Mo KR), mm-1
F(000)
cryst size, mm
θ range, deg
rflns collected
rflns unique (Rint
max./min. transmn
factor
0.29 × 0.19 × 0.10
2.18-27.47
5585
5347 (0.0415)
0.5612/0.2532
0.32 × 0.22 × 0.13
1.81-30.52
21457
7864 (0.0318)
0.5180/0.2571
)
no. of data/restr/
params
5347/6/260
7864/1/297
GOFa
1.053
0.841
R indices [I>2σ(I)]b
R1 ) 0.0493
wR2 ) 0.1161
R1 ) 0.0731
wR2 ) 0.1293
1.114, -0.843
R1 ) 0.0244
wR2 ) 0.0383
R1 ) 0.0475
wR2 ) 0.0413
0.873, -0.777
R indices (all data)
largest peak, hole,
e‚Å-3
2
b
aGOF ) [∑w(Fo - Fc2)2/(nobs - nparam)]1/2
.
R1 ) ∑||Fo| - |Fc||/
∑|Fo|; wR2 ) [∑w(Fo - Fc2)2/∑w(Fo2)2]1/2
.
2
atom of one phenyl ring (supplying proof of the ortho-
metalation), and to the vinylic CdC double bond. The
Pt-Cl bond distances [Pt(1)-Cl(1) ) 2.394(2) Å and Pt-
(1)-Cl(2) ) 2.291(3) Å] are in the usual range of
distances found for this type of bond.16 These distances
are clearly different from each other, with the longer
Pt-Cl bond trans to the arylic carbon atom. Although
it is known that olefin groups have a stronger trans
effect than aryl groups,17 it has also been reported that
(17) Greenwood, N. N.; Earnshaw, A. Chemistry of the Elements;
Pergamon Press: Oxford, 1984; p 1352.
(18) Purcell, K. F.; Kotz, J . C. Inorganic Chemistry; W. B. Saunders
Co.: Philadelphia, 1977; p 705.
(19) Brent Young, G. In Comprehensive Organometallic Chemistry
II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press:
New York, 1995; Vol. 9, p 533.
(16) Orpen, A. G.; Brammer, L.; Allen, F. H.; Kennard, O.; Watson,
D. G.; Taylor, R. J . Chem. Soc., Dalton Trans. 1989, S1.
(20) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. J . Chem. Soc., Perkin Trans. 2 1987, S1.

1432 Organometallics, Vol. 20, No. 7, 2001
Falvello et al.
nium salts the reaction occurs with double C-H acti-
vation at two different sites, one methylene group and
one phenyl ring, while in the case of semistabilized allyl-
phosphonium salts the reaction formally involves C-H
activation at a phenyl ring followed by an isomerization
process. Moreover, we have found an easy synthesis of
vinyl-phosphonium salts from the corresponding allyl-
phosphonium salts by thermal isomerization. Further
work on the reactivity of the coordinated vinyl group is
now in progress.
Exp er im en ta l Section
Sa fety Note: Caution! Perchlorate salts of metal complexes
with organic ligands are potentially explosive. Only small
amounts of these materials should be prepared, and they
should be handled with great caution. See J . Chem. Ed. 1973,
50, A335-A337.
Gen er a l Meth od s. Solvents were dried and distilled under
nitrogen before use. Elemental analyses were carried out on
a Perkin-Elmer 240-B microanalyzer. Infrared spectra (4000-
200 cm-1) were recorded on a Perkin-Elmer 883 infrared
spectrophotometer from Nujol mulls between polyethylene
sheets. 1H (300.13 MHz), 13C{1H} (75.47 MHz), and 31P{1H}
(121.49 MHz) NMR spectra were recorded in CDCl3 or
CD2Cl2 solutions at room temperature (unless otherwise
stated) on a Bruker ARX-300 spectrometer; 1H and 13C{1H}
were referenced using the solvent signal as internal standard,
and 31P{1H} was externally referenced to H3PO4 (85%). The
two-dimensional 1H-1H NOESY experiments for complexes
1b (1bR and the mixture 1bR/1bâ) were performed at a
measuring frequency of 300.13 MHz. The data were acquired
using a phase-sensitive method into a 512 × 1024 matrix and
then transformed into 1024 × 1024 points using a sine window
in each dimension. The mixing time was 400 ms. Mass spectra
(positive and/or negative ion FAB) were recorded on a V. G.
Autospec spectrometer from CH2Cl2 solutions. The bisphos-
phonium salts [R2PhPCH2C(O)CH2PPhR2]X2 (R ) Ph and/or
Et; X ) Cl, ClO4)9a-c and the allyl-phosphonium salts [PhR2-
PCH2-C(R′)dC(H)(R′′)]X (R ) Me, Ph; R′ ) H, Me; R′′ ) H,
Me, Ph; X ) Cl, ClO4; not all possible combinations)9d,e were
prepared according to published methods or with slight
modifications.
[P t(C6H4-2-P P h 2C(H)COCH2P P h 3)Cl2], 1a . To a suspen-
sion of PtCl2(NCPh)2 (0.200 g, 0.42 mmol) in 2-methoxyethanol
(20 mL) was added [Ph3PCH2COCH2PPh3]Cl2 (0.270 g, 0.42
mmol), and this mixture was stirred at the reflux temperature
for 22 h. During this time some decomposition was evident,
and a green solution was obtained. The cold solution was
filtered over Celite, and the resulting pale yellow solution was
treated with 200 mL of Et2O. Further stirring gave 1a as a
white solid, which was filtered, washed with Et2O (100 mL),
and dried in vacuo. Obtained: 0.240 g (67% yield). Anal. Calcd
for C39H32Cl2OP2Pt‚C3H8O2: C, 54.79; H, 4.37. Found: C,
54.39; H, 4.28. IR (ν, cm-1): 1647 (νCO), 293 (νPt-Cl), 263 (νPt-Cl).
1H NMR (CD2Cl2): δ (ppm) 7.97-6.99 (m, 29H, Ph+C6H4), 6.43
F igu r e 4. Thermal ellipsoid plot of [PtCl3(η2-PhCHdCH-
CH2PPh3)], 8. Ph groups of the PPh3 fragment (except Cipso
)
and H atoms are omitted for clarity. Atoms are drawn at
the 50% probability level. Cl(1′) and Cl(3′) are the minor
disordered components.
Ta ble 3. Selected Bon d Len gth s [Å] a n d An gles
[d eg] for 8
Pt(1)-C(2)
Pt(1)-Cl(1′)
Pt(1)-Cl(3)
Pt(1)-Cl(1)
P(1)-C(22)
P(1)-C(1)
2.138(3)
2.274(14)
2.2956(7)
2.3220(7)
1.791(3)
1.814(3)
1.383(4)
Pt(1)-C(3)
Pt(1)-Cl(3′)
Pt(1)-Cl(2)
P(1)-C(16)
P(1)-C(10)
C(1)-C(2)
C(3)-C(4)
2.178(3)
2.295(14)
2.3104(8)
1.791(3)
1.795(3)
1.504(4)
1.477(4)
C(2)-C(3)
C(2)-Pt(1)-C(3)
C(3)-Pt(1)-Cl(1′)
C(3)-Pt(1)-Cl(3′)
C(2)-Pt(1)-Cl(3)
37.37(10) C(2)-Pt(1)-Cl(1′) 105.0(5)
79.0(5)
97.2(4)
C(2)-Pt(1)-Cl(3′)
72.6(4)
Cl(1′)-Pt(1)-Cl(3′) 175.6(6)
87.48(8) C(3)-Pt(1)-Cl(3)
97.19(7)
162.08(8)
95.5(4)
C(2)-Pt(1)-Cl(2) 160.48(8) C(3)-Pt(1)-Cl(2)
Cl(1′)-Pt(1)-Cl(2) 87.7(5) Cl(3′)-Pt(1)-Cl(2)
88.38(3) C(2)-Pt(1)-Cl(1)
Cl(3)-Pt(1)-Cl(2)
C(3)-Pt(1)-Cl(1)
Cl(2)-Pt(1)-Cl(1)
C(3)-C(2)-C(1)
C(2)-C(3)-C(4)
C(4)-C(3)-Pt(1)
95.52(8)
85.81(7) Cl(3)-Pt(1)-Cl(1) 176.84(3)
88.47(3) C(2)-C(1)-P(1)
112.75(18)
72.86(15)
69.77(15)
124.7(2)
129.3(3)
116.53(18)
C(3)-C(2)-Pt(1)
C(2)-C(3)-Pt(1)
2.3104(8), Pt(1)-Cl(3) ) 2.2956(7) Å] are in the usual
range of distances found for this type of bond,16 and
similarly for the Pt-Cvinyl bond distances [Pt(1)-C(2)
) 2.138(3) Å and Pt(1)-C(3) ) 2.178(3) Å].19 The
environment around the P atom is tetrahedral; the
P-Caryl bond distances are nearly identical [P(1)-C(16)
) 1.791(3) Å, P(1)-C(22) ) 1.791(3) Å, P(1)-C(10) )
1.795(3) Å], but the P-CR bond is slightly longer [P(1)-
C(1) ) 1.814(3) Å]. The C2-C3 bond distance [1.383(4)
Å] is similar to that found in 4a and elongated for the
same reasons; the C1-C2 bond distance [1.504(4) Å] is
typical for a C-C single bond,20 and the C3-C4 bond
distance [1.477(4) Å] matches the value expected [1.470-
(15) Å] for a Csp2-Caryl bond.20 Finally, the olefin unit
again deviates from planarity, as seen from the dihedral
angle C1-C2-C3-C4, which is 147.2(5)°.
2
2
4
(ddd, CH2P, 1H, J H-H ) 17.4 Hz, J P-H ) 10.5 Hz, J P-H
)
2
4
1.5 Hz), 4.50 (dd, C(H)Pt, 1H, J P-H ) 4.8 Hz, J P-H ) 2.1 Hz,
2J Pt-H ) 114 Hz), 4.33 (dd, CH2P, 1H, J P-H ) 13.8 Hz). 31P-
2
{1H} NMR (CD2Cl2): δ (ppm) 25.10 (d, PPh2 in ring, J P-P
)
4
8.1 Hz), 20.91 (d, CH2PPh3). 13C{1H} NMR (CD2Cl2): δ (ppm)
186.44 (d, CO, 2J P-C ) 6 Hz), 145.96 (d, C1, C6H4, 2J P-C ) 22.64
Hz), 137.21 (d, C6H4, J P-C ) 14 Hz), 135.04-128.92 (m,
Ph+C6H4), 126.15 (d, C6H4, J P-C ) 15 Hz), 125.10 (d, C6H4,
J P-C ) 13 Hz), 122.96 (d, C6H4, J P-C ) 13 Hz), 119.21 (d,
4. Con clu sion . We have found that simple PtII
complexes such as PtCl2(NCR)2 (R ) Me, Ph) or PtCl2
itself are excellent precursors for the synthesis of
orthometalated compounds derived from keto-stabilized
bis-phosphonium salts or semistabilized allyl-phospho-
nium salts. In the case of keto-stabilized bis-phospho-
1
3
C
ipso-Ph, J P-C ) 88 Hz), 37.56 (dd, CH2P,1J P-C ) 56 Hz, J P-C
1
3
) 12 Hz), 36.00 (dd, C(H)Pt, J P-C ) 62 Hz, J P-C ) 7 Hz).
[P t (C6H 4-2-P P h E tC(H )COCH 2P P h 2E t )Cl2], 1b . PtCl2-
(NCPh)2 (0.200 g, 0.42 mmol) and [EtPh2PCH2COCH2PPh2-
Et]Cl2 (0.230 g, 0.42 mmol) were refluxed for 22 h in 25 mL of

C-H Activation in Phosphonium Salts
Organometallics, Vol. 20, No. 7, 2001 1433
2-methoxyethanol. After cooling, a white solid precipitated.
This solid was filtered, washed with Et2O (20 mL), and dried
in vacuo. Obtained: 0.108 g (34.3% yield). This solid was
identified by NMR as one of the two possible diastereoisomers
of 1b (1bR, RPRC/SPSC, see text). The alcohol solution was
treated with 150 mL of Et2O, giving a second fraction of 1b.
Obtained: 0.119 g (37.5% yield). This second fraction was
characterized spectroscopically as a mixture of the two dias-
tereoisomers (1bR/1bâ) in molar ratio (R/â ) 1:4; configuration
of 1bâ: SPRC/RPSC, see text). Total yield: 71.8%. Anal. Calcd
for C31H32Cl2OP2Pt: C, 49.74; H, 4.31. Found: C, 49.62; H,
4.67. IR (ν, cm-1): 1644 (νCO), 289 (νPt-Cl), 250 (νPt-Cl). MS (FAB
yield). (b) To a suspension of PtCl2(NCMe)2 (0.200 g, 0.52
mmol) in 20 mL of 2-methoxyethanol was added [Ph3PCH2-
COCH2PPh3](ClO4)2 (0.410 g, 0.52 mmol), and this mixture was
refluxed for 5 h. The initial suspension gradually dissolved,
and some decomposition was evident. After reflux, the hot
solution was filtered and the yellow filtrate was allowed to
cool, resulting in the precipitation of 3a as an off-white solid.
Obtained: 0.350 g (75% yield). (c) In a way similar to that
described in (b) PtCl2(NCPh)2 (0.200 g, 0.42 mmol) reacted with
[Ph3PCH2COCH2PPh3](ClO4)2 (0.320 g, 0.42 mmol) in refluxing
2-methoxyethanol, giving 3a as a white solid. Obtained: 0.260
g (55% yield). Anal. Calcd for C78H64Cl4O10P4Pt2: C, 51.55; H,
3.55. Found: C, 51.73; H, 3.98. IR (ν, cm-1): 1652 (νCO), 283
(νPt-Cl). MS (FAB +) [m/z, (%)]: 1717 (40%) [(M2 - ClO4)+]. 1H
NMR (CD2Cl2): δ (ppm), 7.86-7.09 (m, Ph, both isomers), 5.26
(dd, CH2P, major, 2J H-H ) 19.2 Hz, 2J P-H ) 11.4 Hz), 5.16 (dd,
1
+) [m/z, (%)]: 748 (2%) [M+]. H NMR (CD2Cl2): δ (ppm) for
the R isomer, 8.18-7.57 (m, 16H, Ph+C6H4), 7.16-7.06 (m,
3H, C6H4), 6.15 (t, CH2P, 1H, 2J H-H ) 2J P-H ) 14 Hz), 4.31 (d,
2
2
C(H)Pt, 1H, J P-H ) 1.8 Hz, J Pt-H ) 114 Hz), 3.72 (t, CH2P,
1H, J H-H ) 2J P-H ) 14 Hz), 3.54 (m, CH2, 1H), 3.24 (m, CH2,
CH2P, major, J P-H ) 10.2 Hz), 4.89 (dd, CH2P, minor, J H-H
2 2
2
2
2
1H), 2.64 (m, CH2, 1H), 2.50 (m, CH2, 1H), 1.32 (dt, CH3, 3H,
) 17.7 Hz, J P-H ) 14.1 Hz), 4.68 (dd, CH2P, minor, J P-H )
2
3J P-H ) 20.4 Hz, J H-H ) 7.5 Hz), 1.04 (dt, CH3, 3H, J P-H
)
14.10 Hz), 4.69 (d, C(H)Pt, major, J P-H ) 1.5 Hz), 4.61 (t,
2 4
3
3
3
18.6 Hz, J H-H ) 6.9 Hz); δ (ppm) for the â isomer, 8.10-7.53
(m, 16H, Ph+C6H4), 7.11-6.95 (m, 3H, C6H4), 5.79 (ddd, CH2P,
C(H)Pt, minor, J P-H ) J P-H ) 2.1 Hz). 31P{1H} NMR (CD2-
4
Cl2): δ (ppm), 32.10 (d, PPh2 in ring, minor, J P-P ) 7.9 Hz),
2
2
4
4
1H, J H-H ) 16.5 Hz, J P-H ) 10.5 Hz, J P-H ) 1.2 Hz), 4.25
30.59 (d, PPh2 in ring, major, J P-P ) 7.9 Hz), 22.96 (d, CH2-
2
4
2
(dd, C(H)Pt, 1H, J P-H ) 5.7 Hz, J P-H ) 1.8 Hz, J Pt-H ) 117
PPh3, minor), 22.91 (d, CH2PPh3, major).
2
Hz), 3.78 (dd, CH2P, 1H, J P-H ) 14.7 Hz), 3.30 (m, CH2, 1H),
[P t(C6H4-2-P P h EtC(H)COCH2P P h 2Et)(µ-Cl)]2(ClO4)2, 3b.
Complex 3b was synthesized following the same experimental
method as that described for 3a : PtCl2 (0.250 g, 0.96 mmol)
was reacted with [EtPh2PCH2COCH2PPh2Et](ClO4)2 (0.650 g,
0.96 mmol) in 2-methoxyethanol (40 mL) for 4 h, giving 3b as
a white solid. Obtained: 0.379 g (48.5 % yield). This fraction
was identified spectroscopically as the mixture of two diaste-
reoisomers, with molar ratio (major/minor) ) 1.5:1. The alcohol
solution was stirred with 150 mL of Et2O, giving a second crop
of 3b. Obtained: 0.298 g (38.2% yield). This fraction shows
eight resonances in its 31P{1H} NMR, around 36 ppm, with
the same distribution as that observed in the first fraction (see
text). (Total yield: 86.7%). Anal. Calcd for C62H64Cl4O10P4Pt2:
C, 45.82; H, 3.96. Found: C, 45.62; H, 4.15. IR (ν, cm-1): 1652
(νCO), 284 (νPt-Cl). MS (FAB +) [m/z, (%)]: 1425 (40%) [(M2 -
2 ClO4 - H)+]. 1H NMR (CD2Cl2) for the first fraction: δ (ppm),
7.77-7.13 (m, Ph+C6H4), 4.81 (dd, CH2P, major, 2J H-H ) 17.4
Hz, 2J P-H ) 14.4 Hz), 4.80 (dd, CH2P, minor, 2J H-H ) 17.4 Hz,
3.08 (m, CH2, 1H), 2.99 (m, CH2, 1H), 2.85 (m, CH2, 1H), 1.23
3
3
(dt, CH3, 3H, J P-H ) 20.4 Hz, J H-H ) 7.5 Hz), 1.18 (dt, CH3,
3H, J P-H ) 19 Hz, J H-H ) 7.8 Hz). 31P{1H} NMR (CD2Cl2):
3
3
4
δ (ppm) for the R isomer, 32.91 (d, PPhEt in ring, J P-P ) 7.2
Hz), 26.67 (d, CH2PPh2Et); δ (ppm) for the â isomer, 31.32 (d,
PPhEt in ring, J P-P ) 6.6 Hz), 26.37 (d, CH2PPh2Et).
4
[P t (C6H4-2-P E t 2C(H)COCH 2P P h E t 2)Cl2], 1c. Following
the same experimental method as that described for 1a , PtCl2-
(NCPh)2 (0.200 g, 0.42 mmol) reacted with [Et2PhPCH2COCH2-
PPhEt2]Cl2 (0.190 g, 0.42 mmol) in 25 mL of 2-methoxyethanol
for 22 h. Complex 1c precipitated as an off-white solid.
Obtained: 0.220 g (80% yield). Anal. Calcd for C23H32Cl2OP2-
Pt: C, 42.34; H, 4.94. Found: C, 42.17; H, 4.62. IR (ν, cm-1):
1641 (νCO), 290 (νPt-Cl), 257 (νPt-Cl). MS (FAB +) [m/z, (%)]: 652
(45%) [M+]. 1H NMR (CD2Cl2): δ (ppm), 8.07-7.95 (m, Ph, 2H),
7.71-7.66 (m, Ph, 3H), 7.08-7.01 (m, C6H4, 4H), 5.54 (dd,
2
2
CH2P, 1H, J H-H ) 15.9 Hz, J P-H ) 11.7 Hz), 4.05 (dd, C(H)-
Pt, 1H, 2J P-H ) 5.4 Hz, 4J P-H ) 1.2 Hz, 2J Pt-H ) 119 Hz), 3.54
(t, CH2P, 1H, J H-H
2J P-H ) 14 Hz), 4.70 (dd, CH2P, major, J P-H ) 14.4 Hz), 4.49
2
2
2
)
2J P-H ) 15.9 Hz), 3.00 (m, CH2, 2H),
(dd, CH2P, minor, J P-H ) 14.4 Hz), 4.35 (t, C(H)Pt, major,
2.88 (m, CH2, 2H), 2.56 (m, CH2, 1H), 2.43 (m, CH2, 1H), 2.21
2J P-H ) 4J P-H ) 1.8 Hz), 4.22 (t, C(H)Pt, minor, 2J P-H ) 4J P-H
(m, CH2, 2H), 1.22 (m, CH3, 12H). 31P{1H} NMR (CD2Cl2): δ
) 2 Hz, J Pt-H ) 40 Hz), 3.06-2.53 (m, CH2), 1.31-1.03 (m,
2
4
(ppm), 39.19 (d, PEt2 in ring, J P-P ) 5.22 Hz), 32.87 (d, CH2-
CH3). 31P{1H} NMR (CD2Cl2) for the first fraction: δ (ppm),
38.33 (d, PPhEt in ring, major, 4J P-P ) 7.5 Hz), 36.95 (d, PPhEt
PPhEt2).
4
in ring, minor, J P-P ) 7 Hz), 26.31 (d, CH2PPhEt2, minor),
[P h 3P CH2COCH2P P h 3][P tCl4], 2. To a suspension of PtCl2
(0.200 g, 0.75 mmol) in 25 mL of 2-methoxyethanol was added
[Ph3PCH2COCH2PPh3]Cl2 (0.48 g, 0.75 mmol), and the result-
ing suspension was refluxed for 3 h. During this time the
initial suspension gradually dissolved, and after dissolution,
a pale-rose solid precipitated. The cool suspension was filtered,
and the solid was washed with 2-methoxyethanol (10 mL),
then with Et2O (30 mL), and dried in vacuo. Obtained: 0.400
g (58.6% yield). Anal. Calcd for C39H34Cl4OP2Pt: C, 51.05; H,
3.72. Found: C, 50.63; H, 3.71. IR (ν, cm-1): 1723 (νCO), 318
(νPt-Cl). MS (FAB +) [m/z, (%)]: 579 (60%) [(Ph3PC(H)COCH2-
PPh3)+]. This compound was insoluble in the usual organic
solvents (including DMSO-d6), preventing the measurement
of NMR spectra.
[P t(C6H4-2-P P h 2C(H)COCH2P P h 3)(µ-Cl)]2(ClO4)2, 3a . (a)
To a suspension of PtCl2 (0.200 g, 0.75 mmol) in 20 mL of
2-methoxyethanol was added [Ph3PCH2COCH2PPh3](ClO4)2
(0.580 g, 0.75 mmol), and the resulting suspension was
refluxed for 30 min. During this time the color of the suspen-
sion changed from brown to white. The resulting solid was
filtered, washed with Et2O (30 mL), dried in vacuo, and
identified spectroscopically as 3a , as a mixture of the two anti
diastereoisomers (RR/ SS) and (RS/ SR). The molar ratio was
(major/minor) ) 1.6:1 (see text). Obtained: 0.540 g (80.3%
26.12 (d, CH2PPhEt2, major). 31P{1H} NMR (CD2Cl2) for the
second fraction: δ (ppm), 38.47, 38.34, 37.65, 37.02, 36.86,
36.37, 35.83, 35.79 (d, PPhEt in ring), 26.32-25.20 (m, CH2-
PPhEt2).
[P t(C6H4-2-P Et2C(H)COCH2P P h Et2)(µ-Cl)]2(ClO4)2, 3c.
Complex 3c was obtained similarly to 3a : PtCl2 (0.250 g, 0.96
mmol) was reacted with [Et2PhPCH2COCH2PPhEt2](ClO4)2
(0.552 g, 0.96 mmol) in refluxing 2-methoxyethanol (20 mL)
for 4 h, giving 3c as a white solid. Obtained: 0.613 g (91%
yield). Complex 3c was obtained as a mixture of the two
diastereoisomers (RR/ SS) and (RS/ SR) in 1:1 molar ratio.
Anal. Calcd for C64H64Cl4O10P4Pt2: C, 38.78; H, 4.65. Found:
C, 38.92; H, 5.07. IR (ν, cm-1): 1656 (νCO), 285, 249 (νPt-Cl).
MS (FAB +) [m/z, (%)]: 1333 (65%) [(M2-ClO4)+]. 1H NMR
(CD2Cl2): δ (ppm), 8.05-7.09 (m, Ph+C6H4, both isomers),
4.69-4.53 (m, CH2P), 4.31-4.14 (m, CH2P), 4.07 (t, C(H)Pt,
4
2
4
2J P-H ) J P-H ) 2.1 Hz), 4.00 (t, C(H)Pt, J P-H ) J P-H ) 1.8
Hz), 2.82-2.13 (m, CH2, both isomers), 1.45-1.06 (m, CH3,
both isomers). 31P{1H} NMR (CD2Cl2): δ (ppm), 43.17 (d, PEt2
4
4
in ring, J P-P ) 6.7 Hz), 42.99 (d, PEt2 in ring, J P-P ) 6.7
Hz), 32.43 (d, CH2PPhEt2) 32.24 (d, CH2PPhEt2).
[P t(C6H4-2-P P h 2-E-η2-C(H)dC(H)Me)Cl2], 4a . To a solu-
tion of PtCl2(NCPh)2 (0.200 g, 0.42 mmol) in 2-methoxyeth-

1434 Organometallics, Vol. 20, No. 7, 2001
Falvello et al.
anol (20 mL) was added [Ph3PCH2CHdCH2]Cl (0.143 g, 0.42
mmol), and this mixture was refluxed for 22 h. Some decom-
position was evident after the reaction time, and the warm
suspension was filtered over Celite. The resulting pale yel-
low solution was evaporated to ca. 5 mL, giving 4a as a
white solid, which was filtered, washed with Et2O (20 mL),
and dried in vacuo. Obtained: 0.148 g (61% yield). White
crystals of 4a were obtained by crystallization from CH2Cl2/
Et2O. These crystals contain dichloromethane of crystalliza-
tion, as can be observed in the 1H NMR and in the crystal
structure of 4a ‚CH2Cl2. Anal. Calcd for C21H19Cl2PPt‚1.5CH2-
Cl2: C, 38.84; H, 3.19. Found: C, 38.49; H, 2.82. IR (ν, cm-1):
1587, 1571, 1548 (νCdC), 326, 285 (νPt-Cl). MS (FAB +) [m/z,
[m/z, (%)]: 303 (100%) [(Ph3PCH2CHCH2)+]. MS (FAB -) [m/z,
(%)]: 301 (100%) [(PtCl3)-]. 1H NMR (CD2Cl2): δ (ppm), 7.91-
7.60 (m, 15H, Ph), 4.77 (m, 1H, dCH), 4.39-4.25 (m, 3H, CH2P
+ dCH2), 4.00 (m, 1H, dCH2). 31P{1H} NMR (CD2Cl2):
δ
(ppm), 18.34 (J Pt-P ) 156.1 Hz). 13C{1H} NMR (CD2Cl2):
4
3
136.12 (d, Cpara, J P-C ) 2.5 Hz), 134.23 (d, Cmeta, J P-C ) 9.9
2
1
Hz), 131.17 (d, Cortho, J P-C ) 12.7 Hz), 117.47 (d, Cipso, J P-C
1
) 86.0 Hz), 68.95 (s, dCH, J Pt-C ) 217 Hz), 67.52 (d, dCH2,
1
1
3J P-C ) 4.6 Hz, J Pt-C ) 193 Hz), 27.35 (d, PCH2, J P-C ) 48
Hz).
Isom er iza tion of th e Allyl-p h osp h on iu m sa lt [P h 3-
P CH2CHdCH2]Br . Syn th esis of th e Vin yl-p h osp h on iu m
E-[P h 3P CHdCHMe]Br , 6. The allyl-phosphonium salt [Ph3-
PCH2CHdCH2]Br (0.223 g, 0.58 mmol) was refluxed in 2-meth-
oxyethanol (10 mL) for 22 h. The resulting solution was
evaporated to a small volume (ca. 2 mL) and Et2O was added,
giving 6 as a white solid, which was filtered and air-dried.
Obtained: 0.193 g (87% yield). 1H NMR (CDCl3): δ (ppm),
1
(%)]: 533 (20%) [(M - Cl)+], 496 (40%) [(M - 2Cl - H)+]. H
3
NMR (CD2Cl2): δ (ppm), 8.11 (ddq, 1H, H6, J H6-H5 ) 8.1 Hz,
6
3
4J H6-H4 ) 3.3 Hz, J H6-Me ) 0.3 Hz, J Pt-H6 ) 42 Hz), 7.91-
3
7.52 (m, 10H, Ph), 7.42 (tt, 1H, H5, J H5-H6
)
3J H5-H4 ) 8.1
4
5
3
Hz, J H5-H3 = J P-H5 ) 1.5 Hz), 7.24 (tdd, 1H, H4, J H4-H3
)
3J H4-H5 ) 8.1 Hz, 4J H4-H6 ) 3.3 Hz, 4J P-H4 ) 1.2 Hz), 7.17 (ddd,
2
7.79-7.54 (m, 15H, Ph), 7.50 (ddq, 1H, PC(H)), J P-H ) 22.2
3
3
4
1H, H3, J P-H3 ) 11.1 Hz), 4.66 (m, 1H, dC(H)P), 4.56 (dd,
Hz, J H-H ) 16.5 Hz, J H-Me ) 1.5 Hz), 6.55 (ddq, 1H, dC(H)-
3
3
2
3
3
3
1H, dC(H)Me, J H-H ) 12 Hz, J P-H ) 17.1 Hz, J Pt-H ) 59
Me, J P-H ) 21.9 Hz, J H-H ) 16.5 Hz, J H-Me ) 6.6 Hz), 2.25
4
3
3
4
4
Hz), 1.84 (d, 3H, dC(H)Me, J Me-Hcis ) 5.7 Hz, J Pt-Me ) 44
(ddd, 3H, dC(H)Me, J H-Me ) 6.6 Hz, J P-H ) 2.1 Hz, J H-Me
) 1.5 Hz). 31P{1H} NMR (CDCl3): δ (ppm), 18.62 (s). 13C{1H}
NMR (CDCl3): δ (ppm), 159.77 (d, dC(H)Me), 2J P-C ) 2.2 Hz),
Hz). 31P{1H} NMR (CD2Cl2): δ (ppm), 25.84 (3J Pt-P ) 48.6 Hz).
13C{1H} NMR (CD2Cl2): δ (ppm), 146.56 (d, C1, C6H4, J P-C
)
,
2
16.4 Hz), 137.29 (d, C4, C6H4, 3J P-C ) 14.1 Hz), 135.36 (d, Cpara
4
135.29 (d, Cpara, PPh3, J P-C ) 2.5 Hz), 133.87 (d, Cmeta, PPh3,
Ph, 4J P-C ) 2.6 Hz), 135.15 (d, Cpara, Ph, 4J P-C ) 2.6 Hz), 133.41
3J P-C ) 10.5 Hz), 130.53 (d, Cortho, PPh3, J P-C ) 12.9 Hz),
2
3
3
118.11 (d, Cipso, PPh3, 1J P-C ) 90.8 Hz), 110.25 (d, PC(H), 1J P-C
(d, Cmeta, Ph, J P-C ) 10.2 Hz), 133.38 (d, Cmeta, Ph, J P-C
)
4
3
10.5 Hz), 133.17 (d, C5, C6H4, J P-C ) 2.9 Hz), 132.64 (d, C6,
) 86.5 Hz), 21.89 (d, dC(H)Me, J P-C ) 19.4 Hz).
3
2
C6H4, J P-C ) 15.1 Hz), 130.71 (d, Cortho, Ph, J P-C ) 13 Hz),
Oth er Attem p ted Isom er iza tion s of Allyl-p h osp h o-
n iu m Sa lts. The allyl-phosphonium salt [Ph3PCH2CHdCH2]-
ClO4 was refluxed in 2-methoxyethanol (10 mL) for 22 h. The
resulting solution was evaporated to a small volume (ca. 2 mL)
and Et2O was added, giving a white solid. The NMR spectra
of this solid show the presence of the allyl and vinyl phospho-
niums in a molar ratio (allyl:vinyl) ) 1.88:1.
130.68 (d, Cortho, Ph, 2J P-C ) 12 Hz), 126.80 (d, C3, C6H4, 2J P-C
1
) 13.5 Hz), 125.14 (d, C2, C6H4, J P-C ) 106 Hz), 121.60 (d,
1
1
C
ipso, Ph, J P-C ) 76 Hz), 120.83 (d, Cipso, Ph, J P-C ) 93 Hz),
81.53 (s, dCHMe, 1J Pt-C ) 223.2 Hz), 57.91 (d, dC(H)P, 1J P-C
1
3
) 77.8 Hz, J Pt-C ) 244.6 Hz), 21.61 (d, dC(H)Me, J P-C
)
10.1 Hz).
[P t(C6H4-2-P Me2-E-η2-C(H)dC(H)Me)Cl2], 4b. Complex
4b was obtained following the same experimental method as
that described for 4a : PtCl2(NCPh)2 (0.200 g, 0.42 mmol) and
[PhMe2PCH2CHdCH2]Br (0.110 g, 0.42 mmol) were refluxed
in 2-methoxyethanol (20 mL) for 22 h, giving 4b as a white
solid, which was filtered, washed with Et2O (20 mL), and dried
[P t(C6H4-2-P P h 2-E-η2-C(H)dC(H)Et)Cl2], 7. Complex 7
was obtained following the same experimental method as that
described for 4a : PtCl2 (0.250 g, 0.94 mmol) and [Ph3PCH2-
CHdCHMe]Br (0.373 g, 0.94 mmol) were refluxed in 2-meth-
oxyethanol (20 mL) for 22 h, giving 7 as a white solid, which
was filtered, washed with Et2O (20 mL), and dried in vacuo.
Obtained: 0.121 g (22% yield). White crystals of 7 can be
obtained by crystallization from CH2Cl2/Et2O. These crystals
contain dichloromethane of crystallization, as can be observed
in the 1H NMR. Anal. Calcd for C22H21Cl2PPt‚2CH2Cl2: C,
38.32; H, 3.35. Found: C, 38.66; H, 3.10. IR (ν, cm-1): 1589,
1569, 1546 (νCdC), 315, 278 (νPt-Cl). MS (FAB +) [m/z, (%)]: 548
(40%) [(M - Cl)+], 509 (75%) [(M - 2Cl - H)+]. 1H NMR
in vacuo. Obtained: 0.174 g (92% yield). Anal. Calcd for C11H15
-
Cl2PPt: C, 29.74; H, 3.40. Found: C, 29.36; H, 3.22. IR (ν,
cm-1): 1573, 1550 (νCdC), 289, 271 (νPt-Cl). MS (FAB +) [m/z,
1
(%)]: 407 (35%) [(M - Cl)+], 371 (60%) [(M - 2Cl - H)+]. H
NMR (DMSO-d6): δ (ppm), 7.83 (m, 1H, C6H4), 7.54 (m, 1H,
C6H4), 7.23 (m, 1H, C6H4), 4.56-4.09 (br m, 2H, C(H)dC(H)P),
2
2
2.22 (d, 3H, PMe, J P-H ) 14.4 Hz), 2.20 (d, 3H, PMe, J P-H
)
)
)
4
3
3
4
14.7 Hz), 1.58 (d, 3H, dC(H)Me, J Me-Hcis ) 5.4 Hz, J Pt-Me
(CDCl3): δ (ppm), 8.18 (dd, 1H, H6, J H6-H5 ) 7.5 Hz, J H6-H4
28.2 Hz). 31P{1H} NMR (DMSO-d6): δ (ppm), 32.38 (3J Pt-P
3
) 3.0 Hz, J Pt-H6 ) 36 Hz), 7.91-7.50 (m, 10H, Ph), 7.36 (tt,
48.7 Hz). 13C{1H} NMR (CD2Cl2): This compound was in-
soluble for 13C NMR measurements, even in DMSO-d6.
3
4
1H, H5, J H5-H6
)
3J H5-H4 ) 7.5 Hz, J H5-H3
=
5J P-H5 ) 0.9
3
Hz), 7.15 (m, 2H, H3 + H4), 4.61 (dd, 1H, dC(H)P, J H-H
)
2
[P tCl3(η2-CH2dCH-CH2P P h 3)], 5. (a) To a suspension of
PtCl2 (0.200 g, 0.75 mmol) in 2-methoxyethanol (15 mL) was
added [Ph3PCH2CHdCH2]ClO4 (0.303 g, 0.75 mmol), and this
suspension was refluxed for 22 h. During this time, extensive
decomposition and formation of a Pt0 mirror was observed. The
black mixture was filtered through Celite, and the resulting
yellow solution was evaporated to dryness. The addition of
Et2O (30 mL) to the oily residue and subsequent stirring gave
5 as a yellow solid, which was filtered, washed with additional
Et2O (15 mL), and air-dried. Obtained: 0.159 g (35% yield).
(b) To a suspension of PtCl2 (0.200 g, 0.75 mmol) in toluene
(15 mL) was added [Ph3PCH2CHdCH2]Cl (0.255 g, 0.75 mmol),
and this suspension was refluxed for 1 h. During this time,
the color of the suspension changed from brown to pale yellow.
After cooling, 5 was obtained as a yellow solid, which was
filtered, washed with toluene (10 mL) and Et2O (25 mL), and
air-dried. Obtained: 0.394 g (86.6% yield). Anal. Calcd for
13.5 Hz, J P-H ) 17.1 Hz), 4.53 (m, 1H, dC(H)Et), 2.47 (m,
1H, dC(H)CH2CH3), 1.95 (m, 1H, dC(H)CH2CH3), 1.21 (t, 3H,
dC(H)CH2CH3, J H-H ) 7.2 Hz). 31P{1H} NMR (CDCl3):
δ
δ
3
(ppm), 25.42 (3J Pt-P ) 45.8 Hz). 13C{1H} NMR (CDCl3):
2
(ppm), 146.11 (d, C1, C6H4, J P-C ) 16.4 Hz), 137.18 (d, C4,
3
C6H4, J P-C ) 14.1 Hz), 134.95 (s, Cpara, Ph), 134.65 (d, Cpara
,
4
3
Ph, J P-C ) 2.3 Hz), 133.07 (d, Cmeta, Ph, J P-C ) 10.5 Hz),
3
132.95 (s, C5, C6H4), 132.80 (d, Cmeta, Ph, J P-C ) 10.4 Hz),
3
132.00 (d, C6, C6H4, J P-C ) 15.2 Hz), 130.30 (d, 2 Cortho, Ph,
2J P-C ) 11.8 Hz), 126.41 (d, C3, C6H4, 2J P-C ) 13.4 Hz), 124.70
1
1
(d, C2, C6H4, J P-C ) 106.3 Hz), 121.35 (d, Cipso, Ph, J P-C
)
1
97.4 Hz), 120.23 (d, Cipso, Ph, J P-C ) 114.8 Hz), 86.87 (s, d
1
1
CHEt, J Pt-C ) 233.5 Hz), 55.67 (d, dC(H)P, J P-C ) 77.4 Hz,
1J Pt-C ) 235.2 Hz), 28.58 (d, dC(H)CH2CH3, J P-C ) 9.3 Hz),
3
13.47 (s, dC(H)CH2CH3).
[P tCl3(η2-P h CHdCH-CH2P P h 3)], 8, a n d [P t(C6H4-2-
P P h 2-η2-E-C(H)dC(H)CH2P h )Cl2], 9. To a suspension of
PtCl2 (0.250 g, 0.94 mmol) in 2-methoxyethanol (20 mL) was
added [Ph3PCH2CHdCHPh]Cl (0.389 g, 0.94 mmol), and this
C
21H20Cl3PPt: C, 41.70; H, 3.33. Found: C, 42.16; H, 3.37. IR
(ν, cm-1): 1589 (νCdC), 340 (sh), 332, 317 (νPt-Cl). MS (FAB +)

C-H Activation in Phosphonium Salts
Organometallics, Vol. 20, No. 7, 2001 1435
mixture was refluxed for 22 h. The resulting suspension was
cooled, and the green precipitate was filtered. This green solid
was recrystallized from CH2Cl2/Et2O, giving 8 as a deep yellow
solid. Obtained: 0.200 g (31.2% yield based on Pt). The
alcoholic mother liquor was evaporated to dryness, and the
oily residue was washed with water (3 × 10 mL), to eliminate
some remaining starting phosphonium salt. The residue was
redissolved in 5 mL of CH2Cl2, dried with MgSO4, evaporated
to dryness, and treated with Et2O (20 mL), giving 9 as a white
solid. Obtained: 0.342 g (56.5% yield based on Pt). White
crystals of 9‚0.3CH2Cl2, obtained by recrystallization of 9 from
CH2Cl2/Et2O, were used for analytical and spectroscopic
measurements.
J P-C ) 14.6 Hz), 134.97 (s, Cpara, PPh2), 134.46 (d, Cpara, PPh2,
4J P-C ) 2.6 Hz), 133.19 (d, Cmeta, PPh2, 3J P-C ) 10.9 Hz), 132.80
3
2
(d, Cmeta, PPh2, J P-C ) 10.3 Hz), 130.45 (d, Cortho, PPh2, J P-C
2
) 13.4 Hz), 130.27 (d, Cortho, PPh2, J P-C ) 13.7 Hz), 127.34
1
(d, C2, C6H4, J P-C ) 105.9 Hz), 126.09 (d, C6H4, J P-C ) 13.6
1
Hz), 121.95 (d, Cipso, PPh2, J P-C ) 92.6 Hz), 120.37 (d, Cipso
,
1
PPh2, J P-C ) 75.9 Hz), 101.36 (s, dCMe2), 58.56 (d, )C(H)P,
1J P-C ) 79.2 Hz), 33.08 (d, dCMe2, 3J P-C ) 10.7 Hz), 28.35 (d,
3
dCMe2, J P-C ) 3.4 Hz).
Com p ou n d 11. Anal. Calcd for C22H22ClP: C, 74.89; H,
6.28. Found: C, 74.81; H, 6.47. IR (ν, cm-1): 1621, 1587 (νCd
C). MS (FAB +) [m/z, (%)]: 317 (100%) [M - Cl+]. 1H NMR
(CDCl3): δ (ppm), 7.81-7.53 (m, 15H, PPh3), 6.20 (d, 1H, d
2
C(H)P, J P-H ) 22.8 Hz), 2.36 (s, 3H, Me-cis-to-P), 1.72 (dd,
Com p ou n d 8. Anal. Calcd for C27H24Cl3PPt: C, 47.63; H,
3.55. Found: C, 47.23; H, 3.59. IR (ν, cm-1): 1588 (νCdC), 330,
327, 312 (νPt-Cl). MS (FAB +) [m/z, (%)]: 379 (100%) [(Ph3-
PCH2CHCHPh)+]. (FAB -) [m/z, (%)]: 301 (100%) [PtCl3-].
1H NMR (CD2Cl2): δ (ppm), 7.87-7.63 (m, 15H, PPh3), 7.38-
7.29 (m, 3H, Ph), 7.23-7.18 (m, 2H, Ph), 6.06 (dd, 1H, dC(H),
4
3H, Me-trans-to-P, J P-H ) 2.4 Hz). 31P{1H} NMR (CDCl3): δ
(ppm), 11.38. 13C{1H} NMR (CDCl3): δ (ppm), 172.62 (s, d
CMe2), 135.15 (d, Cpara, PPh3, 4J P-C ) 2.2 Hz), 133.42 (d, Cmeta
,
3
2
PPh3, J P-C ) 10.6 Hz), 130.78 (d, Cortho, PPh3, J P-C ) 12.8
Hz), 119.34 (d, Cipso, PPh3, 1J P-C ) 89.8 Hz), 103.13 (d, dC(H)P,
3
1J P-C ) 89.6 Hz), 30.26 (d, Me-trans-to-P, J P-C ) 18.2 Hz),
4
3J H-H ) 12.6 Hz, J P-H ) 0.9 Hz, J Pt-H ) 69.9 Hz), 5.29 (m,
3
2
2
24.95 (d, Me-cis-to-P, J P-C ) 7.6 Hz).
1H, dC(H)), 4.43 (ddd, 1H, PCH2, J H-H ) 15.6 Hz, J P-H
)
3
2
Isom er iza tion of [P h 3P CH2C(Me)dCH2]Cl. Syn th esis
of [P h 3P CHdCMe2]Cl, 11. The allyl-phosphonium salt [Ph3-
PCH2CMedCH2]Cl (0.200 g, 0.567 mmol) was refluxed in
2-methoxyethanol (10 mL) for 22 h. The resulting solution was
evaporated to a small volume (ca. 2 mL) and Et2O was added,
giving 11 as a white solid, which was filtered and air-dried.
Obtained: 0.180 g (90% yield).
Cr ysta l Str u ctu r e Deter m in a tion of 4a ‚CH2Cl2 a n d 8.
Crystals of complexes 4a ‚CH2Cl2 and 8 of adequate quality
for X-ray measurements were obtained by slow vapor conden-
sation of Et2O over a CH2Cl2 solution of the corresponding
crude complex (4a or 8). Each crystal was mounted at the end
of a quartz fiber and covered with epoxy.
Da ta Collection for 4a ‚CH2Cl2. Geometric and intensity
data were measured using normal procedures on an automated
Nonius CAD-4 four-circle diffractometer. After preliminary
indexing and transformation of the cell to a conventional
setting, axial photographs were taken of the a-, b- and c-axes
to verify the Laue symmetry and cell dimensions. The scan
parameters for intensity data collection were chosen on the
basis of two-dimensional (ω-θ) plots of 25 reflections. Three
monitor reflections were measured after every 3 h of beam
time, and the orientation of the crystal was checked after every
400 intensity measurements. Absorption corrections21 were
based on azimuthal scans of 14 reflections which had Eulerian
angles ø spread between 50° and -40° when in their bisecting
positions. Accurate unit cell dimensions were determined from
25 centered reflections in the 2θ range 27.3° e 2θ e 30.9°,
each centered at four distinct goniometer positions.
Da ta Collection for 8. A single crystal of dimensions 0.32
× 0.22 × 0.13 mm was mounted on a glass fiber in a random
orientation. Data collection was performed at room tempera-
ture on a Bruker Smart CCD diffractometer using graphite-
monocromated Mo KR radiation (λ ) 0.71073 Å) with a
nominal crystal-to-detector distance of 4.0 cm. A hemisphere
of data was collected based on three ω-scan runs (starting ω
) -30°) at values φ ) 0°, 90°, and 180° with the detector at
2θ ) 30°. For each of these runs, frames (606, 435, and 230,
respectively) were collected at 0.3° intervals and 20 s per
frame. The diffraction frames were integrated using the
program SAINT,22 and the integrated intensities were cor-
rected for absorption with SADABS.23
12.3 Hz, J H-H ) 4.8 Hz), 4.10 (ddd, 1H, PCH2, J H-H ) 15.6
Hz, J P-H ) 12.3 Hz, J H-H ) 9.0 Hz). 31P{1H} NMR (CD2Cl2):
2
3
δ (ppm), 18.37 (3J Pt-P ) 177.2 Hz). 13C{1H} NMR (CD2Cl2) (the
C
ipso of the olefinic Ph group was not observed): δ (ppm), 137.51
3
(s, Cpara, PPh3), 135.61 (d, Cmeta, PPh3, J P-C ) 9.9 Hz), 132.56
2
(d, Cortho, PPh3, J P-C ) 12.6 Hz), 130.77 (s, Cmeta, Ph), 130.54
(s, Cpara, Ph), 130.37 (s, Cortho, Ph), 118.94 (d, Cipso, PPh3, 1J P-C
2
) 85.6 Hz), 87.83 (d, dCH, J P-C ) 5.2 Hz), 61.52 (d, dC(H),
3J P-C ) 1.8 Hz, J Pt-C ) 226.4 Hz), 28.41 (d, CH2P, J P-C
)
1
1
45.8 Hz).
Com p ou n d 9. Anal. Calcd for C27H23Cl2PPt‚0.3CH2Cl2: C,
48.94; H, 3.55. Found: C, 48.81; H, 3.74. IR (ν, cm-1): 1588,
1571, 1547 (νCdC), 323, 278 (νPt-Cl). MS (FAB +) [m/z, (%)]: 573
1
(15%) [(M - 2Cl-H)+]. H NMR (CDCl3): δ (ppm), 8.18 (ddd,
3
4
4
1H, H6, J H6-H5 ) 7.8 Hz, J H6-H4 ) 3.3 Hz, J P-H6 ) 0.3 Hz,
3J Pt-H6 ) 37.8 Hz), 7.82-6.93 (m, 18H, PPh2 + C6H4 + Ph),
4.68 (dd, 1H, dC(H)P, 3J H-H ) 16.5 Hz, 2J P-H ) 11.7 Hz, 2J Pt-H
) 58.8 Hz), 4.56 (m, 1H, dC(H)CH2Ph), 3.76 (dd, 1H, dC(H)-
2
3
CH2Ph, J H-H ) 13.8 Hz, J H-H ) 9.6 Hz), 3.67 (dd, 1H, d
C(H)CH2Ph, J H-H ) 13.8 Hz, J H-H ) 4.5 Hz). 31P{1H} NMR
(CDCl3): δ (ppm), 26.79 (3J Pt-P ) 35.6 Hz). 13C{1H} NMR
(CDCl3) (two quaternary C atoms of the C6H4 ring were not
found, probably because of overlapping): δ (ppm), 145.78 (d,
C1, C6H4, 2J P-C ) 16.3 Hz), 137.42 (s, Cipso, Ph), 137.07 (d, C6H4,
J P-C ) 14.0 Hz), 135.57 (s, Cpara, PPh2), 135.52 (s, Cpara, PPh2),
133.90 (d, Cmeta, PPh2, 3J P-C ) 10.7 Hz), 132.66 (d, Cmeta, PPh2,
3J P-C ) 10.4 Hz), 131.09 (d, C6H4, J P-C ) 15.1 Hz), 130.55 (d,
2
3
2
2
C
ortho, PPh2, J P-C ) 12.6 Hz), 130.28 (d, Cortho, PPh2, J P-C
12.7 Hz), 127.14 (s, Cortho, Ph), 126.64 (s, Cpara, Ph), 126.51 (s,
)
1
C
C
meta, Ph), 124.33 (d, C2, C6H4, J P-C ) 106.3 Hz), 120.51 (d,
1 1
ipso, PPh2, J P-C ) 76.4 Hz), 120.02 (d, Cipso, PPh2, J P-C
)
1
92.7 Hz), 82.85 (s, dCHCH2Ph, J Pt-C ) 237.2 Hz), 55.25 (d,
1
1
dC(H)P, J P-C ) 77.1 Hz, J Pt-C ) 255.6 Hz), 41.21 (d,
3
dCHCH2Ph, J P-C ) 8.9 Hz).
[P t(C6H4-2-P P h 2-η2-C(H)dCMe2)Cl2], 10, a n d [P h 3P C-
(H)dCMe2]Cl, 11. Following the same experimental method
as that described for 4a , PtCl2 (0.250 g, 0.939 mmol) and [Ph3-
PCH2C(Me)dCH2]Cl (0.331 g, 0.939 mmol) were reacted in
refluxing 2-methoxyethanol (15 mL) for 22 h to give 0.220 g
of a mixture of the organometallic compound 10 and the vinyl-
phosphonium salt 11 in 1:2.1 molar ratio (see text).
1
Com p ou n d 10. H NMR (CDCl3): δ (ppm), 8.12 (ddt, 1H,
Str u ctu r e Solu tion a n d Refin em en t. The structures
were solved and developed by Patterson and Fourier meth-
3
4
4
H6, J H6-H5 ) 7.8 Hz, J H6-H4 ) 3.0 Hz, J P-H6 ) 5J H6-H3 ) 0.9
3
Hz, J Pt-H6 ) 46.8 Hz), 7.93-7.53 (m, 10H, PPh2), 7.36-7.29
(m, 1H, C6H4), 7.21-7.17 (m, 2H, C6H4), 4.63 (d, 1H, dC(H)P,
(21) Absorption corrections and molecular graphics were done using
the commercial package: SHELXTL-PLUS, Release 5.05/V; Siemens
Analytical X-ray Instruments, Inc.: Madison, WI, 1996.
(22) SAINT Version 5.0; Bruker Analytical X-ray Systems, Madison,
WI, 1996.
(23) Sheldrick, G. M. SADABS: Empirical absorption correction
program; University of Gottingen, 1996.
2J P-H ) 15.6 Hz, 2J Pt-H ) 68.7 Hz), 2.02 (s, 3H, dCMe2, 3J Pt-H
) 36.0 Hz), 1.28 (s, 3H, dCMe2, J Pt-H ) 51.6 Hz). 31P{1H}
3
NMR (CDCl3): δ (ppm), 23.35 (3J Pt-P ) 45.1 Hz). 13C{1H} NMR
(CDCl3) (two carbon atoms of the C6H4 group were not found):
δ (ppm), 147.60 (d, C1, C6H4, 2J P-C ) 18.3 Hz), 136.99 (d, C6H4,

1436 Organometallics, Vol. 20, No. 7, 2001
Falvello et al.
ods.24 All non-hydrogen atoms were refined with anisotropic
displacement parameters. The hydrogen atoms were placed
in idealized positions and treated as riding atoms, except for
those of the methyl groups, which were first located in a local
slant-Fourier calculation and then refined as riding atoms with
the torsion angles about the C-C(methyl) bonds treated as
variables. Each hydrogen atom was assigned an isotropic dis-
placement parameter equal to 1.2 times the equivalent iso-
tropic displacement parameter of its parent atom. For complex
8 the chlorine atoms Cl1 and Cl3 are disordered over two
positions, with relative populations 95% and 5%. The major
congener was refined with anisotropic displacement param-
eters and the minor one with isotropic displacement param-
eters. The structures were refined to Fo2, and all reflections
were used in the least-squares calculations.25 Crystallographic
calculations were done on an AlphaStation (OPEN/VMS V6.2).
Data reduction for 4a ‚CH2Cl2 was done by the program
XCAD4B.26
(Spain, Projects PB98-1595-C02-01, PB98-1044, and
PB98-1593) and Fundacio´ Caixa Castello´-Bancaixa
through Project P1B98-07 is gratefully acknowledged,
and we thank Prof. J . Fornie´s for invaluable logistical
support. We are most indebted to the “Servei Central
d’Instrumentacio´ Cient´ıfica” (SCIC) of the University
J aume I for the use of the X-ray facilities.
Su p p or tin g In for m a tion Ava ila ble: Tables giving com-
plete data collection parameters, atomic coordinates, complete
bond distances and angles, and thermal parameters for 4a ‚
CH2Cl2 and 8. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM001034I
(24) Sheldrick, G. M. SHELXS-86. Acta Crystallogr. 1990, A46, 467.
(25) Sheldrick, G. M. SHELXL-97: FORTRAN program for the
refinement of crystal structures from diffraction data; Go¨ttingen
University, 1997.
Ack n ow led gm en t. Funding by the Direccio´n Gen-
eral de Investigacio´n Cient´ıfica y Te´cnica (DGICYT)
(26) Harms, K. Private communication, 1995.