Synthesis and characterization of PdII complexes containing cyclic bis-ylides

Article abstract of DOI:10.1016/S0020-1693(02)01448-2

The reaction of Ph₂PCH₂PPh₂ (dppm) with ClCH₂C(O)CH₂Cl (1:1 molar ratio) in refluxing CHCl₃ gives the new ylide-phosphonium salt 1, through quaternization of the two P atoms of the dppm and

Full text of DOI:10.1016/S0020-1693(02)01448-2

Inorganica Chimica Acta 347 (2003) 75Á85
/
www.elsevier.com/locate/ica
Synthesis and characterization of PdII complexes containing cyclic
bis-ylides
Larry R. Falvello, Marina E. Margalejo, Rafael Navarro *, Esteban P. Urriolabeitia
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n, Universidad de Zaragoza-Consejo Superior de Investigaciones
Cient´ıficas, E-50009 Zaragoza, Spain
Received 25 March 2002; accepted 25 June 2002
Dedicated in honor of Professor R. Uso´n
Abstract
The reaction of Ph2PCH2PPh2 (dppm) with ClCH2C(O)CH2Cl (1:1 molar ratio) in refluxing CHCl3 gives the new ylide-
phosphonium salt 1, through quaternization of the two P atoms of the dppm and spontaneous loss of HCl. Compound 1 reacts with
NEt3 in CHCl3 or CH2Cl2 solution (1:1 molar ratio) giving a mixture of the bis-ylide compound 2a and the ylide-methanide 2b
(molar ratio 2a:2bꢀ
complex 3a (coordination through the two ylidic carbons) and the dichloride(ylide-methanide) complex 3b (coordination through
the ylide carbon and the methanide carbon), in a molar ratio 3a:3bꢀ1:2. The reaction of the mixture 3a:3b with AgClO4 (1:2 molar
ratio, NCMe or Me2CO) in the presence of neutral ligands L gives the corresponding mixtures of the dicationic complexes
[Pd(L)2(C,C-bis-ylide)](ClO4)2 (4a, LꢀNCMe; 5a, Lꢀpyridine) and [Pd(L)2(C,C-ylide-methanide)](ClO4)2 (4b, LꢀNCMe; 5b,
Lꢀpyridine) (molar ratio 4a:4bꢀ1:2; molar ratio 5a:5bꢀ3:1). On the other hand, the reaction of Ph2PCH2PPh2 (dppm) with
ClCH2C(ꢀ
CH2)CH2Cl (1:1 molar ratio) in refluxing ClCH2CH2Cl gives the bis-phosphonium salt 6. This salt reacts with LitBu and
PdCl2(NCMe)2 (1:2.2:1 molar ratio) in THF affording the ylide-methanide complex 7. The crystal structures of complexes 3b×3dmso
CHCl3 have been determined by X-ray diffraction.
/
1:2). This mixture (prepared in situ) reacts with PdCl2(NCMe)2 to give the corresponding dichloride(bis-ylide)
/
/
/
/
/
/
/
/
/
and 7×
/
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: P-ylides; Heterocycles; Palladium; Crystal structures
1. Introduction
As part of our ongoing research into a-stabilized
ylides [13], we have undertaken the synthesis of new
cyclic, stabilized ylides and bis-ylides through quaterni-
zation of the two P atoms of bis(diphenylphosphi-
The coordination chemistry of phosphorus ylides
R3Pꢀ
wards transition metals is now a well established
research area in organometallic chemistry [1Á3]. How-
/
CR?Rƒ (R, R?, Rƒꢀ
/
alkyl, aryl, acyl, etc.) to-
no)methane [Ph2PCH2PPh2ꢀdppm] with 1,3-dihalo
/
derivatives (e.g. 1,3-dichloroacetone). In this way, we
have been able to obtain the new cyclic, six-membered
phosphonium-ylide 1 [(1,1,3,3,-tetraphenyl-1l5,3l5-1-
phosphonia-3-phosphorane-cyclohex-3-en-5-one)chlor-
ide]. We have also studied its reactivity towards
deprotonating reagents and towards simple Pd(II) pre-
cursors. In addition, we have also studied the reactivity,
with Pd(II) precursors, of the cyclic ylide-methanide [5-
methyl-1,1,3,3-tetraphenyl-1l5,3l5-diphosphabenzene]
[5a]. In the present contribution we report the results
obtained.
/
ever, the synthesis of cyclic P-ylides or bis-ylides, and the
study of their complexation to transition metals, is a less
documented field; and very few examples have been
reported in the literature [4Á
importance [10Á12].
/
9], in spite of their practical
/
* Corresponding author.
E-mail addresses: rafanava@posta.unizar.es (R. Navarro),
esteban@posta.unizar.es (E.P. Urriolabeitia).
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0020-1693(02)01448-2

76
L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á85
/
2. Results and discussion
protons. The 13C{1H} NMR spectrum (APT: attached
proton test) of 1 shows the carbonyl resonance at 170.1
ppm (negative phase), and the resonances attributed to
The reaction of dppm with 1,3-dichloroacetone for 12
h (1:1 molar ratio) in deoxygenated CHCl3 at reflux
temperature gives the cyclic ylide-phosphonium salt 1
(see Scheme 1) in good yield as a white solid, insoluble in
most common organic solvents. The reaction occurs
with quaternization of the two P atoms of the dppm
moiety and spontaneous loss of HCl. The IR spectrum
of 1 shows two intense absorptions at 1587 and 1568
cmꢁ1, showing the typical shift to low energy of a
carbonyl group in resonance with an ylide function. This
the Pꢀ
70.0 ppm (dd, JPC
phase), 23.3 ppm (d, JPC
/
C(H), PCH2 and PCH2P carbons at, respectively,
1
3
ꢀ
/
103 Hz, JPC
ꢀ
/
9.5 Hz, positive
46.6 Hz, negative phase)
45.4 Hz, negative phase). The
1
ꢀ
/
1
and 12.3 (t, JPC
ꢀ
/
positions of the resonances, the respective values of
1
the coupling constants JPC and the sign of the phase
signal in the APT spectrum allows an unambiguous
identification of all functional groups present in 1.
Finally, the 31P{1H} NMR spectrum of 1 shows two
broad resonances, centered at 18.4 and at 9.3 ppm, and
shift is frequently found in a-stabilized ylides Ph3Pꢀ
/
attributed to the PCH2 and Pꢀ
/
C(H) groups, respec-
1
C(H)C(O)R [1Á3,13]. The simultaneous presence of an
/
tively. This attribution has been confirmed by H{31P}
NMR measurements.
ylide unit and a phosphonium moiety is clearly inferred
1
from the NMR spectra of 1. The H NMR spectrum of
The synthesis of 1 merits comment. This facile process
contrasts with that described for the related, acyclic, bis-
phosphonium salt [Ph3PCH2C(O)CH2PPh3]Cl2, which
must be performed with longer reaction times (up to 20
h) and in the presence of a huge excess of PPh3 (molar
1 shows, in addition to the aromatic resonances, three
signals centered at 6.20 (t), 5.82 (d) and 5.10 ppm (d) of
relative intensity 2:1:2; these resonances are attributed,
respectively, to the PCH2P, Pꢀ
/
CH and PCH2CO
ratio PPh3:1,3-dichloroacetoneꢀ20:1) [14,15]. Prob-
/
ably, this very different behavior can be due to a greater
stabilization of the six-membered structure in 1 by
cyclization, compared with the acyclic structure. More-
over, it is surprising to observe the spontaneous loss of
HCl in the synthesis of 1 under relatively mild condi-
tions (CHCl3, reflux, 12 h). We have reported a similar
result (loss of HCl) in the treatment of
[Ph3PCH2C(O)CH2PPh3]Cl2, but under quite harsh
conditions (refluxing 2-methoxyethanol, 22 h) [16], and
with the difference that the amount of the corresponding
ylide-phosphonium salt [Ph3Pꢀ
/CHC(O)CH2PPh3]Cl
obtained is just at trace level.
Compound 1 still presents two activated methylene
groups, susceptible to deprotonation by an external
base. When a suspension of 1 (CH2Cl2) was treated with
a stoichiometric amount of NEt3 (molar ratio 1:1), a
clear colorless solution was obtained in a few seconds
(see Scheme 1). The reaction was monitored by NMR
1
(performed in CDCl3 or CD2Cl2); and the H NMR
spectrum shows that the cation [HNEt3]Cl is present in
solution, indicating that deprotonation has taken place.
In addition, two new species (2a and 2b), in 1/2 molar
ratio, have been formed. The 31P{1H} NMR spectrum
of this solution shows three different signals, an AB spin
2
system (doublets centered at 16.6 and 11.4 ppm; JPP
ꢀ
/
38.4 Hz) and a singlet resonance at 8.9 ppm (relative
intensity 1:1:1); no resonances attributed to the starting
product 1 were found. The singlet resonance at 8.9 ppm
is assigned to the new symmetric bis-ylide 2a (Scheme 1),
due to the similarity of its chemical shift with that found
for the ylide P atom in 1 (9.3 ppm), and which is formed
by deprotonation of the methylene adjacent to the
carbonyl group in 1. The AB spin system is assigned
to the asymmetric ylide-methanide 2b, formed by
Scheme 1.

L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á
/85
77
1
deprotonation of the CH2 group located between the
two P atoms, and for which the resonance at 11.4 ppm is
4.05 ppm. Moreover, for compound 3b, the H NMR
spectrum shows four different signals corresponding to
the four chemically inequivalent protons of the different
functional groups: (i) the PCH2CO protons appear as an
AB spin system coupled with 31P at very different
chemical shifts (4.62 and 3.34 ppm); (ii) the methanide
proton P2C(H)Pd appears at 4.26 ppm as a triplet; (iii)
the ylide proton PC(H)Pd appears at 3.64 ppm as a
doublet.
attributed to the ylide P atom [P ꢀ
/
CHC(O)] while the
signal at 16.6 ppm is assigned to the methanide P atom
[CHꢀ
/
PCH2].
The 1H NMR spectrum shows resonances corre-
sponding to the mixture 2a:2b (1/2 molar ratio). For
compound 2b, the ylide proton Pꢀ
/
C(H) appears at 3.85
2
ppm (d, JPH
ꢀ
/
12.6 Hz), the methanide proton Pꢀ
/
2
2
14.4 Hz, JPH
C(H)ꢁP at 3.36 ppm (dd, JPH
/
ꢀ
/
ꢀ/2.4
The different natures of the carbon atoms in 3a and
3b can be clearly distinguished in the 13C{1H} (APT)
NMR spectrum of the mixture 3a/3b. Two resonances
with negative phase are attributed to two methylene
Hz), and the methylene protons PCH2 at 3.18 ppm (d,
2JPH
12.0 Hz). For compound 2a, the ylide protons
PꢀC(H) appear at 3.73 ppm (d, JPH
ꢀ
/
2
/
ꢀ25.8 Hz), while
/
the resonance attributed to the PCH2P protons is not
observed, probably hidden by the signals of the protons
of the [HNEt3]ꢂ cation.
Unfortunately, all attempts to isolate the compounds
2a and 2b in pure form from the reaction mixture were
unsuccessful, since the product was always contami-
nated with ammonium salts. The same results were
obtained when other classical deprotonating reagents,
such as 1,8-bis(dimethylamino)naphthalene or other
groups*
the PCH2CO carbon of 3b and the resonance at 22.4 (t,
1JPC
52.9 Hz) to the P2CH2 cabon atom of 3a. And
three signals with positive phase are assigned to the
three types of coordinated CH atoms*a doublet at 30.7
ppm (1JPC
53.1 Hz) to the ylidic carbon atom in 3a,
another doublet at 20.9 ppm (1JPC
54.9 Hz) to the
ylide carbon in 3b and the triplet appearing at ꢁ13.4
/
the resonance at 32.6 ppm (d, 1JPC
ꢀ
/
51 Hz) to
ꢀ
/
/
ꢀ
/
ꢀ
/
/
ppm (1JPC
ꢀ38.9 Hz) to the methanide carbon atom,
/
amines were employed. The use of Tl(acac) (acacꢀ
acetylacetonate), which allows the synthesis of the
phosphonium-ylide CHC(O)CH2PPh3]ClO4
[Ph3Pꢀ
starting from the bis-phosphonium salt
/
also in 3b. As expected, the 31P{1H} NMR spectrum of 3
shows a singlet resonance for 3a, centered at 18.4 ppm,
2
and an AB spin system for 3b (8.8 and 7.7 ppm, JPP
/
ꢀ
/
11.3 Hz). The molecular structure of 3b×
/
3dmso has been
[Ph3PCH2C(O)CH2PPh3](ClO4)2 [17], Ag(OOCCH3),
or hard bases (NaH, LinBu) also fails to provide a
satisfactory synthetic method to isolate the mixture 2a/
2b from the side products of the reaction. In our hands,
the reaction with NEt3 is the best choice for generating
the 2a/2b mixture, and this can be used in situ.
determined by X-ray diffraction, and provides further
structural characterization (see below).
Each of the components of the mixture 3a/3b seems to
be quite robust, since the mixture does not show any
noticeable signs of decomposition or evolution after
treatment in refluxing 2-methoxyethanol for 24 h; and,
moreover, the composition of the mixture remains
Thus, the reaction of 1 with NEt3 in CH2Cl2, followed
by addition of PdCl2(NCMe)2 (1:1:1 molar ratio) to the
colorless solution of the mixture 2a/2b produces an
orange solution, from which product 3 precipitates as a
yellow solid (see Scheme 1). The presence of two cis-
chloride ligands can be inferred from the IR spectrum of
virtually constant (3a:3bꢀ1:2). On the other hand,
/
each complex, 3a and 3b, contains an activated meth-
ylene group (3a between the two P atoms and 3b
adjacent to the carbonyl unit) which, in principle, can
be deprotonated. We have studied the reactivity of the
mixture (3a:3b) towards some deprotonating reagents,
such as (acac)AuPPh3 and Hg(OOCCH3)2 (both re-
agents gave a very interesting reactivity in orthometal-
lated ylides containing a phosphonium functionality)
[18], but in both cases mixtures of the starting com-
pounds were recovered.
More successful were the substitution reactions of the
chloride ligands by neutral ligands L. The mixture 3a:3b
reacts with AgClO4 (1:2 molar ratio) in NCMe to
give the corresponding dicationic complexes [Pd-
(NCMe)2(bis-ylide)](ClO4)2 4a and [Pd(NCMe)2(ylide-
methanide)](ClO4)2 4b (Scheme 1). The molar ratio
4a:4b was 1:2 (see Experimental). In the same way, the
reaction of 3a:3b with AgClO4 (1:2 molar ratio) in
acetone and, after filtration of the AgCl, further
treatment of the resulting solution with pyridine (ex-
cess), afford a mixture of the complexes [Pd(py)2(bis-
ylide)](ClO4)2 5a and [Pd(py)2(ylide-methanide)](ClO4)2
3, which shows two absorptions at 302 and 290 cmꢁ1
and the presence of coordinated ylide is inferred from
the observation of a strong absorption at 1635 cmꢁ1
,
,
shifted to higher energies when compared with com-
pound 1. Further spectroscopic characterization of 3
shows that it is actually a mixture of the symmetric
complex 3a (generated by coordination of the two ylidic
carbons of the bis-ylide 2a) and the asymmetric complex
3b (a result of the coordination of the ylide and the
methanide carbon atoms of 2b), in 1:2 molar ratio, the
same ratio as that observed for compounds 2a and 2b.
The C,C-coordination of the bis-ylide in complex 3a
produces a loss of symmetry in the ylide, as reflected in
the 1H NMR spectrum of 3a; the PCH2P protons appear
at 5.54 and 5.34 ppm as an AB spin system*
by coupling with the two chemically equivalent P
atoms*while the ylidic protons are still chemically
equivalent and appear as a broad singlet resonance at
/and split
/

78
L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á85
/
5b (Scheme 1). In this case the molar ratio obtained is
5a:5bꢀ3:1.
scopic parameters of 6 are in good agreement with those
reported in the literature [5b].
/
The characterization of the mixtures 4a:4b and 5a:5b
has been carried out by analytical and spectroscopic
methods. The IR spectrum of 4a:4b shows absorptions
due to the NCMe ligands (2324, 2295 cmꢁ1) and to the
carbonyl of the ylide groups (1667 cmꢁ1), while the IR
spectrum of 5a:5b shows absorptions due to the pyridine
ligands (1607 cmꢁ1) and to the carbonyl group of the
From a comparison of the syntheses of compounds 1
and 6, it seems clear that the presence of a carbonyl unit
in 1 activates the adjacent methylene groups enough to
allow a spontaneous deprotonation (probably, in the
form of HCl), and that in further deprotonations
(performed with soft bases under mild conditions) two
possible reaction sites must be considered (leading to the
formation of the isomers a and b). However, in the
bis(phosphonium) 6 the presence of an olefin moiety
does not produce a similar activating effect, and a cyclic
compound with three methylene groups is obtained. The
first deprotonation of 6 can also be produced under very
mild conditions, but it is completely selective. A
suspension of 6 reacts instantaneously with NEt3 (1:1
molar ratio) in CHCl3 to give a clear, colorless solution.
The reaction can be monitored by NMR spectroscopy
(solvent CDCl3), and in this solution the only identified
species are the methanide-phosphonium salt 6? and the
expected salt [HNEt3]Cl (see Scheme 2 and Section 5).
The spectroscopic parameters of 6? (as the chloride salt,
see Section 5) show clearly that deprotonation has taken
place only at the methylene group between the two
phosphorus atoms; the data are in good agreement with
those reported in the literature for the corresponding
iodide salt [5]. The only difference with the reported
synthetic method is the base employed; in our procedure
we obtain 100% spectroscopic yield using NEt3, and in
the published method the deprotonating reagents are
LinBu or triethylethyledenephosphorane. Our attempts
to coordinate compound 6? to a Pd(II) center failed,
probably due to the very poor nucleophilic character of
the deprotonated carbon atom. Thus, the reaction of the
chloride of 6? with PdCl2(NCMe)2 (1:2 molar ratio)
results in the isolation of [6?][PdCl4], and the reaction
with the bis-solvate [Pd(dmba)(THF)2](ClO4)2 (1:1 mo-
1
ylide ligands (1658 cmꢁ1). The H NMR spectrum of
the mixture 4a:4b shows, in addition to the expected
signals due to the Ph groups and the NCMe ligands, a
pattern of resonances very similar to that described for
the mixture 3a:3b*that is, seven different peaks corre-
/
sponding to the seven different types of protons present
in the two complexes (see Scheme 1 and Section 5). The
same applies to the mixture 5a:5b, with understandable
differences arising from the presence of pyridine ligands
instead of NCMe. In addition, the 31P{1H} NMR
spectrum of the mixture 4a:4b shows a singlet at 22.1
ppm, attributed to 4a, and two broad singlets at 17.3
and 11.8 ppm, assigned to 4b. Finally, the 31P{1H}
NMR spectrum of the mixture 5a:5b shows a singlet at
20.9 ppm (5a), and two singlets at 13.7 and 12.2 ppm
(5b).
The reaction of dppm with other 1,3-dihalo deriva-
tives has also been studied. The reaction of dppm with 3-
chloro-2-chloromethyl-1-propene (1:1 molar ratio) in
refluxing 1,2-dichloroethane gives the corresponding
bis-phosphonium salt 6 (see Scheme 2) as a white solid.
This phosphonium derivative has already been reported
by Schmidbaur [5], although starting from different
compounds (1,1-bis[(diphenylphosphino)methyl]ethene
and CH2I2), and the yields are very similar. The present
procedure is somewhat less complicated and less ex-
pensive, since it avoids the synthesis of the diphosphine
1,1-bis[(diphenylphosphino)methyl]ethene. The spectro-
lar ratio; dmbaꢀC6H4CH2NMe2-C,N) gives the di-
/
nuclear [Pd(m-Cl)(dmba)]2 and the perchlorate of 6?.
The double deprotonation of 6 has been reported to
give
5-methyl-1,1,3,3-tetraphenyl-1l5,3l5-diphospha-
benzene [5a], but no reactions with transition metals
have been described. Moreover, very few reports con-
cerning the reactivity of cyclic ylides with transition
metals have appeared [4,7,8]. When a suspension of 6 in
THF was treated with LitBu (1:2.2 molar ratio) a clear
orange solution was formed. This solution-containing
the 5-methyl-1,1,3,3-tetraphenyl-1l5,3l5-diphosphaben-
zene
derivative-was
allowed
to
react
with
PdCl2(NCMe)2 (1:1 molar ratio) at 0 8C, resulting in
the synthesis of 7 (see Scheme 2). Compound 7 was
isolated, as an orange solid, after solvent evaporation,
extraction of the residue with CH2Cl2 and precipitation
with Et2O (see Section 5). It gives correct elemental
analysis and mass spectrum, and its IR spectrum shows
Scheme 2.

L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á
/85
79
the presence of two cis-chloride ligands (two absorp-
tions at 291 and 273 cmꢁ1).
The 1H NMR spectrum of 7 shows all expected
resonances for the proposed stoichiometry. The olefinic
2
proton appears at 5.75 ppm (d, JPH
methanide and ylidic protons appear at 2.72 ppm (broad
ꢀ20.4 Hz), the
/
2
singlet) and 2.67 ppm (d, JPH
ꢀ10.2 Hz), respectively,
/
and the methyl group appears at 2.48 ppm. The C,C-
coordination of the ylide-methanide ligand can be
clearly seen in the 13C{1H} NMR spectrum (APT) of
7. There, the methanide carbon atom [P2C(H)Pd]
1
1
appears at ꢁ
/
17.5 ppm (dd, JPC
ꢀ
/
52.1 Hz, JPC
40.0 Hz), with positive phase, and strongly shifted to
ꢀ
/
high field with respect to the corresponding resonance in
1
3.0 ppm, JPC
the free ligand [5b] (ꢁ
/
ꢀ109.1 Hz), as
/
expected for a hybridization change from sp2 to sp3. The
same arguments apply to the notable change in the
Fig. 1. Thermal ellipsoid plot of complex 3b. Non-hydrogen atoms are
drawn at the 50% probability level. H atoms have been omitted for
clarity.
1
values of the JPC coupling constants. Moreover, the
ylidic carbon atom [PC(H)Pd] appears at 6.3 ppm (dd,
1JPC
ꢀ
/
57.8, 3JPC
ꢀ
/
7.7 Hz), also strongly shifted to high
field with respect to its corresponding value in the free
ligand (51.8 ppm, Jꢀ120.54 Hz). On the other hand,
/
Table 1
Crystal data for 3b×
/
3dmso and 7×
/
CHCl3
the methyl carbon atom appears at virtually the same
chemical shift (29.1 ppm, compared with 30.4 ppm in
Compound
3b×3dmso
/
7×CHCl3
/
the free ligand) but with a different multiplicity (dd,
3JPC
Empirical formula
Molecular weight
Data collection T (K) 173(2)
C34H41Cl2O4P2PdS3
849.09
C30H26Cl5P2Pd
732.10
3
17.0, JPC
ꢀ
/
ꢀ9.1 Hz), reflecting the asymmetry of
/
173(2) K
0.71073
monoclinic
P21/n
compound 7. The redistribution of the electron density
after the C,C-coordination is also reflected in the
olefinic fragment, which possesses now greater double
bond character. The quaternary carbon atom appears
now at 172.2 ppm (while in the free ligand it appears at
˚
l (A)
0.71073
monoclinic
P21/n
Crystal system
Space group
˚
a (A)
11.4199(13)
12.1234(14)
26.861(3)
93.928(2)
3710.1(7)
4
14.877(2)
13.989(2)
15.616(3)
112.887(3)
2994.0(8)
4
˚
b (A)
˚
c (A)
159.5 ppm) and the ꢀ
ppm (dd, ꢀ
CH, 1JPC
with 51.8 ppm, Jꢀ120.54 Hz in the free ligand). These
/
CH carbon atom appears at 96.5
/
ꢀ
/
93.5 Hz, 3JPC
ꢀ/7.2 Hz; compare
b (8)
3
V (A )
˚
/
Z
Dcalc (Mg mꢁ3
)
1.520
0.936
1740
1.624
1.193
1468
downfield shifts are consistent with the putative greater
double bond character. Finally, the 31P{1H} NMR
spectrum shows two singlet peaks, centered at 10.2
and 7.7 ppm. The analysis of the molecular structure of
m (Mo Ka) (mmꢁ1
F(000)
)
Crystal size (mm)
u Range (8)
Reflections collected
0.39ꢃ/0.25ꢃ
/0.16
0.21ꢃ
/
0.15ꢃ0.04
/
1.52Á28.65
/
1.60Á28.78
/
7×
/
CHCl3 by X-ray diffraction provides further struc-
23 730
8709 [0.1004]
19 369
7053 [0.0998]
tural information.
Reflections unique
[Rint
]
Data/restraints/para-
meters
8709/0/426
7052/0/380
3. X-ray crystal structures of compounds 3b×
/
3dmso and
R indices [I ꢀ/2s(I)]
R1ꢀ
0.1793
R1ꢀ0.1358, wR2ꢀ
/
0.0803, wR2ꢀ
/
R1ꢀ
0.1033
R1ꢀ0.1362, wR2ꢀ
/0.0611, wR2ꢀ
/
7×CHCl3
/
R indices (all data)
/
/
/
/
Fig. 1 shows a drawing of 3b, relevant parameters
0.1970
1.005
0.1462
0.895
Goodness-of-fit
concerning data collection and refinement are given in
Table 1 and selected bond distances and angles are
collected in Table 2. The Pd atom is located in a
rhombically distorted square-planar environment,
bonded to the two Cl atoms, the methanide carbon
atom C(1) and the ylidic carbon atom C(2). The largest
Largest difference peak 1.672, ꢁ
/
1.762
0.723, ꢁ0.676
/
ꢁ3
˚
and hole (e A
)
R1ꢀ
ness-of-fitꢀ
/
ajjFojꢁ
/
jFcjj/ajFoj; wR2ꢀ
/
[a w(Fo2ꢁ
ꢁ
/
Fc2)2/a w(Fo2)2]1/2; Good-
/
[a w(Fo2ꢁ
/
Fc2)2/(nobs
/
nparam)]1/2
.
deviation from the best plane defined by Cl(1)ꢁ
/
Cl(2)ꢁ
/
˚
C(2) corresponds to C(2) (ꢂ0.043 A). The
sum of the cis- bond angles about the Pd center is
coordination environment. The atoms C(1) and C(2) are
chiral, although, due to the centrosymmetric nature of
the space group (P21/n), the crystal as a whole is
Pd(1)ꢁ
/
C(1)ꢁ
/
/
360.0(3)8, which indicates the strict planarity of the

80
L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á85
/
Table 2
C(1)ꢁ
/
P(1)ꢁC(2) [95.1(3)8] is rather different from the
/
˚
Bond lengths (A) and angles (8) for 3b×
/
3dmso
ideal value due to the coordination of C(1) and C(2) to
the Pd atom. Similar trends can be observed for the
coordinated carbon atoms. For instance, the bond angle
Bond lengths
Pd(1)ꢁ
Pd(1)ꢁ
/
C(1)
2.099(6)
Pd(1)ꢁ
2.3539(19) Pd(1)ꢁ
/C(2)
2.104(6)
2.3564(17)
1.779(7)
1.799(7)
1.787(7)
1.814(6)
1.203(7)
/Cl(2)
/Cl(1)
P(1)ꢁ
/
C(2)ꢁPd(1) is only 84.4(2)8. The basic skeleton of
/
P(1)ꢁ
P(1)ꢁ
P(2)ꢁ
P(2)ꢁ
C(2)ꢁ
C(3)ꢁ
/
C(1)
C(5)
C(1)
C(23)
1.781(6)
1.796(7)
1.760(7)
1.790(7)
1.452(9)
1.541(10)
P(1)ꢁ
P(1)ꢁ
P(2)ꢁ
P(2)ꢁ
C(3)ꢁ
/C(2)
the ylide-methanide ligand adopts a pseudo-boat con-
formation, with the atoms C(2), C(3), C(1) and P(2)
forming the base of the boat. These four atoms are
almost coplanar, the RMS deviation from the best plane
/
/
C(11)
C(17)
C(4)
/
/
/
/
/
C(3)
/O(1)
˚
is 0.031 A. The atoms located at the corners of the boat
show higher deviations with respect to the same plane:
/
C(4)
Bond angles
C(1)ꢁPd(1)ꢁ
C(2)ꢁPd(1)ꢁ
C(2)ꢁPd(1)ꢁ
C(1)ꢁ
C(2)ꢁ
C(2)ꢁ
C(1)ꢁ
C(17)ꢁ
C(17)ꢁ
P(2)ꢁC(1)ꢁ
P(1)ꢁC(1)ꢁ
C(3)ꢁC(2)ꢁ
O(1)ꢁC(3)ꢁ
C(2)ꢁC(3)ꢁ
˚
˚
/
/
C(2)
Cl(2)
Cl(1)
77.4(2)
C(1)ꢁ
/
Pd(1)ꢁ
Pd(1)ꢁ
170.42(18) Cl(2)ꢁPd(1)ꢁCl(1)
/
Cl(2)
169.75(17)
93.82(17)
96.38(7)
111.2(3)
117.0(3)
107.8(3)
110.1(3)
108.2(3)
109.0(3)
103.5(3)
118.3(5)
84.4(2)
0.297(9) A [C(4)] and 1.019(6) A [P(1)]. The angle
between the perpendiculars to the best least-square
planes defined by [C(1), C(2), C(3), P(2)] and [Pd(1),
Cl(1), Cl(2), C(1), C(2)] is 105.51(17)8.
Fig. 2 shows a drawing of the organometallic
derivative 7, relevant parameters concerning the data
collection and refinement are given in Table 1 and
selected bond distances and angles are collected in Table
3. The structure as a whole is very similar to that of
compound 3b. The palladium atom is located in a
rhombically distorted square-planar environment, sur-
rounded by the two Cl atoms, the methanide carbon
atom C(1) and the ylidic carbon atom C(5). The
/
/
92.37(18) C(1)ꢁ
/
/Cl(1)
/
/
/
/
/
P(1)ꢁ
P(1)ꢁ
P(1)ꢁ
P(2)ꢁ
/
C(2)
95.1(3)
111.4(3)
114.0(3)
110.4(3)
109.7(3)
109.5(3)
111.5(3)
84.5(2)
C(1)ꢁ
C(1)ꢁ
C(5)ꢁ
C(1)ꢁ
C(1)ꢁ
C(23)ꢁ
P(2)ꢁC(1)ꢁ
C(3)ꢁC(2)ꢁ
P(1)ꢁC(2)ꢁPd(1)
O(1)ꢁC(3)ꢁC(4)
C(3)ꢁC(4)ꢁP(2)
/
P(1)ꢁ
P(1)ꢁ
P(1)ꢁ
P(2)ꢁ
P(2)ꢁ
P(2)ꢁ
Pd(1)
P(1)
/
C(5)
/
/
C(5)
/
/
C(11)
C(11)
C(23)
C(4)
/
/
C(11)
C(17)
/
/
/
/
/
/
/
P(2)ꢁ
/
C(23)
/
/
/
P(2)ꢁ
/
C(4)
/
/C(4)
/
/
P(1)
/
/
/
/
Pd(1)
/
/
/
/
Pd(1)
103.0(4)
122.7(7)
119.8(5)
/
/
/
/
C(2)
/
/
117.4(7)
118.3(5)
/
/
C(4)
/
/
coordination plane is defined by Cl(1)ꢁ
C(1)ꢁC(5) and the largest deviation from the best plane
in this case is found at C5 (ꢁ
3b, both carbon atoms C(1) and C(5) are chiral, and the
crystal as a whole is racemic. The absolute configura-
tions shown in Fig. 2 for these carbon atoms are R
/
Cl(2)ꢁ
/
Pd(1)ꢁ
/
racemic. The absolute configurations shown in Fig. 1
are S [C(1)] and R [C(2)].
/
˚
0.087 A). As described for
/
˚
The bond distances Pdꢁ
/
Cl(1) [2.3564(17) A] and Pdꢁ
/
˚
Cl(2) [2.3539(19) A] are identical, within experimental
error, and fall in the range of distances found for this
bond in similar environments (Clꢁ
/
trans-C) [4,19]. The
˚
[C(1)] and S [C(5)]. The bond distances Pdꢁ
/
Cl(1)
Cl(2) [2.3544(15) A] fall in the
same range of distances found for this bond in similar
trans-C) [4,19], but are now different
PdꢁC bond distances PdꢁC(1) [2.099(6) A] and Pdꢁ
/
/
/
˚
˚
[2.377(2) A] and Pdꢁ
/
˚
C(2) [2.104(6) A] are also identical, within experimental
error, and similar to those reported in other cyclic
structures containing ylide and methanide C atoms
environments (Clꢁ
/
from each other, probably due to the different trans
influences of the two carbon atoms. This fact is reflected
linked to palladium [4]. The Pꢁ
remarkable differences. While the P(1)ꢁ
11) bond distances are identical [range 1.779(7)Á
/
C bond distances show
C(n) (nꢀ1, 2, 5,
1.799(7)
C(1) bond distance [1.760(7) A] is shorter
than the other P(2)ꢁC(m) (mꢀ4, 17, 23) bond distances
[range 1.787(7)Á1.814(6) A]. This fact could be due to a
partial double bond character in the P(2)ꢁC(1) bond.
On the other hand, the C(3)ꢁC(4) bond distance
[1.541(10) A] is typical for a s(CꢁC) bond [20], while
/
/
/
˚
˚
A], the P(2)ꢁ
/
/
/
˚
/
/
/
˚
/
˚
the C(2)ꢁ
/
C(3) distance [1.452(9) A] is shorter than that
expected for the same type of bond. The C(3)ꢁ
/O(1)
˚
bond distance [1.203(7) A] is typical for ylides derived
from 1,3-dichloroacetone [18,21].
The bite angle of the ylide-methanide ligand C(1)ꢁ
/
Pd(1)ꢁC(2) is notably acute [77.4(2)8], as befits a four-
/
membered chelate ring; and similar values have been
found in related complexes [4]. The presence of the four
membered chelate ring introduces significant distortions
in the molecule. The environments of both P atoms are
tetrahedral [average of angles 109(3)8 for P(1) and
109.5(3)8 for P(2)] although for P(1) one of the angles
Fig. 2. Thermal ellipsoid plot of complex 7. Non-hydrogen atoms are
drawn at the 50% probability level. H atoms have been omitted for
clarity.

L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á
/85
81
˚
Table 3
Selected bond lengths (A) and angles (8) for 7×
ꢁ
/
1.0425 A from the same plane. The angle between
the best least-squares planes defined by C(1)ꢁC(4)ꢁ
C(5)ꢁP(2) and Cl(1)ꢁCl(2)ꢁPd(1)ꢁC(1)ꢁC(5) is 113.98.
The bite angle of the ligand C(5)ꢁPd(1)ꢁC(1) is 75.1(2)8,
˚
/
CHCl3
/
/
/
/
/
/
/
Bond lengths
/
/
Pd(1)ꢁ
Pd(1)ꢁ
Pd(1)ꢁ
/
C(5)
Cl(2)
P(1)
2.066(5)
Pd(1)ꢁ
/
C(1)
2.091(5)
2.377(2)
1.761(6)
1.364(7)
1.502(7)
1.752(6)
1.815(6)
1.813(6)
very similar to that observed for 3b. The four-membered
chelate ring also gives distortions and deviations of the
regular geometry around the P and coordinated C
atoms, following similar trends to those described for
3b. Finally, it is interesting to remark the presence of a
contact between the chlorine atom Cl(1) and the
/
2.3544(15) Pd(1)ꢁ
/Cl(1)
/
2.583(2)
1.764(6)
1.743(6)
1.497(8)
1.793(6)
1.791(6)
C(1)ꢁ
C(2)ꢁ
C(3)ꢁ
C(5)ꢁ
P(1)ꢁ
P(2)ꢁ
/
P(1)
C(4)
C(4)
P(1)
C(1)ꢁ
C(2)ꢁ
C(4)ꢁ
P(1)ꢁ
P(2)ꢁ
/
P(2)
P(2)
C(5)
/
/
/
/
/
/
C(6)
/
C(12)
/
C(24)
/
C(18)
˚
aromatic proton H29A [2.614(8) A].
Bond angles
C(5)ꢁPd(1)ꢁ
C(1)ꢁPd(1)ꢁ
C(1)ꢁPd(1)ꢁ
C(5)ꢁPd(1)ꢁ
Cl(2)ꢁPd(1)ꢁ
P(1)ꢁC(1)ꢁ
P(2)ꢁC(1)ꢁ
C(2)ꢁC(4)ꢁ
C(5)ꢁC(4)ꢁ
C(4)ꢁC(5)ꢁ
C(5)ꢁP(1)ꢁ
C(1)ꢁP(1)ꢁ
C(1)ꢁP(1)ꢁ
C(5)ꢁP(1)ꢁ
C(6)ꢁP(1)ꢁ
C(2)ꢁP(2)ꢁ
C(1)ꢁP(2)ꢁ
C(1)ꢁP(2)ꢁ
/
/
C(1)
Cl(2)
Cl(1)
P(1)
75.1(2)
169.9(2)
95.0(2)
C(5)ꢁ
C(5)ꢁ
Cl(2)ꢁ
C(1)ꢁPd(1)ꢁ
Cl(1)ꢁPd(1)ꢁ
P(1)ꢁC(1)ꢁPd(1)
C(4)ꢁC(2)ꢁ
C(2)ꢁC(4)ꢁ
C(4)ꢁC(5)ꢁ
P(1)ꢁC(5)ꢁ
C(5)ꢁP(1)ꢁ
C(5)ꢁP(1)ꢁ
C(6)ꢁP(1)ꢁ
C(1)ꢁP(1)ꢁ
C(12)ꢁP(1)ꢁ
C(2)ꢁP(2)ꢁ
C(2)ꢁP(2)ꢁ
C(24)ꢁ
/
Pd(1)ꢁ
Pd(1)ꢁ
Pd(1)ꢁ
P(1)
P(1)
/
Cl(2)
94.8(2)
167.4(2)
94.96(6)
42.7(2)
/
/
/
/Cl(1)
/
/
/
/Cl(1)
4. Conclusion
/
/
42.5(2)
/
/
/
/P(1)
128.28(6)
112.3(3)
107.7(3)
123.5(5)
116.4(5)
109.0(4)
92.3(3)
/
/
124.99(6)
83.8(2)
A new cyclic ylide-phosphonium moiety 1 has been
obtained by the facile quaternization of the two P atoms
of dppm with 1,3-dichloroacetone, followed by loss of
HCl. 1 presents two active methylene groups, and its
reaction with NEt3 produces deprotonation at the two
possible sites. The reaction with Pd(II) complexes gives
mixtures of derivatives with C,C-coordinated bis-ylide
(a) and with C,C-bonded ylide-methanide (b). In con-
trast, the cyclic 5-methyl-1,1,3,3-tetraphenyl-1l5,3l5-
diphosphabenzene bonds to Pd(II) to give the ylide-
methanide complexes exclusively.
/
/
P(2)
/
/
/
/
Pd(1)
/
/
P(2)
C(3)
P(1)
122.3(5)
120.1(6)
114.6(4)
84.7(2)
/
/
C(5)
C(3)
Pd(1)
/
/
/
/
/
/
/
/
/
/Pd(1)
/
/
C(1)
/
/C(6)
115.4(3)
115.6(3)
104.8(3)
53.6(2)
/
/
C(6)
111.5(3)
117.3(3)
52.8(2)
/
/
C(12)
C(12)
Pd(1)
/
/
C(12)
Pd(1)
Pd(1)
C(1)
/
/
/
/
/
/
/
/
95.0(2)
/
/Pd(1)
160.1(2)
107.1(3)
112.4(3)
104.4(3)
/
/
107.1(3)
114.4(3)
111.4(3)
/
/C(24)
/
/
C(24)
C(18)
/
/C(18)
/
/
/
P(2)ꢁC(18)
/
˚
C(1) [2.091(5) A] and
5. Experimental
in the Pdꢁ
PdꢁC(5) [2.066(5) A]*
Pdꢁ
it.
/
C bond distances-Pdꢁ
/
˚
/
/
in such a way that the shorter
5.1. Safety note
/
C bond distance has a longer Pdꢁ/Cl bond trans to
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.
The expected structural changes in the 5-methyl-
1,1,3,3-tetraphenyl-1l5,3l5-diphosphabenzene
ligand
due to coordination are observed, as can be seen from
a comparison of the two crystal structures [5a]. The Pꢁ
/
C
50 (1973) A335ÁA337.
/
˚
bond distances in the ring [P(1)ꢁ
/
C(5): 1.752(6) A; P(1)ꢁ
/
˚
˚
C(1): 1.761(6) A; P(2)ꢁ
/
C(1): 1.764(6) A; P(2)ꢁ
/C(2):
5.2. General methods
˚
1.743(6) A] are all elongated with respect to their
corresponding values in the free ligand [1.729(3);
˚
Solvents were dried and distilled under argon using
standard procedures before use. Elemental analyses
1.699(3); 1.695(3); 1.724(3) A], while the endocyclic Cꢁ
/
C bond distances*
[1.387(4) and 1.393(4) A]*
/
nearly identical in the free ligand
˚
were carried out on a PerkinÁ
lyser. Infrared spectra (4000Á
200 cmꢁ1) were recorded
on a PerkinÁElmer 883 infrared spectrophotometer
/Elmer 240-B microana-
/
are now very different
/
˚
˚
[C(5)ꢁ
former corresponding to a single s(Cꢁ
latter to a double CꢀC bond. These facts match very
well with the NMR data. The CꢁCH3 bond distances
are identical, within experimental error [1.502(7) A in 7
/
C(4): 1.497(8) A and C(2)ꢁ
/
C(4): 1.364(7) A], the
/
from Nujol mulls between polyethylene sheets. 1H
(300.13 MHz), 13C{1H} (75.47 MHz, digital resolution:
0.545 HzpPT) and 31P{1H} (121.49 MHz, digital
resolution 3.050 HzpPT) NMR spectra were recorded
in CDCl3, CD2Cl2 or dmso-d6 solutions at room
temperature (r.t.) (unless otherwise stated) on a Bruker
ARX-300 spectrometer; 1H and 13C{1H} were refer-
enced using the solvent signal as internal standard and
31P{1H} was externally referenced to H3PO4 (85%).
Mass spectra (positive ion FAB) were recorded on a
V.G. Autospec spectrometer from CH2Cl2 or dmso
/C) bond and the
/
/
˚
˚
and 1.516(4) A in the free ligand] [5a]. In addition, the
structure of the ligand changes from a planar disposition
in its free form to a pseudo-boat conformation in 7,
similar to that described for 3b. In this case, the atoms
C(1), C(4), C(5) and P(2) are coplanar, while C(2) atom
˚
deviates by ꢁ0.1004 A from the best least-squares plane
/
defined by the given atoms and P(1) deviates by

82
L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á85
/
solutions. The following starting compounds have been
obtained from commercial sources and used as supplied:
1,3-dichloroacetone, dppm, NEt3, pyridine, LitBu and
5.5. Synthesis of 3
To a suspension of 1 (1.091 g, 2.30 mmol) in CH2Cl2
(20 ml), NEt3 (0.323 ml, 2.30 mmol) was added
dropwise, giving a clear, colorless solution. To this
solution PdCl2(NCMe)2 (0.608 g, 2.30 mmol) was
added, and the resulting orange solution was stirred at
r.t. for 1 h. During this time, complex 3 precipitated as a
yellow solid, which was filtered, washed with CH2Cl2 (5
ml) and Et2O (20 ml) and air dried. Obtained: 1.016 g
H2Cꢀ/C(CH2Cl)2. The complex [PdCl2(NCMe)2] has
been prepared according to published procedures [22]
with minor modifications (solvent change).
5.3. Synthesis of 1
(71.7% yield). Molar ratio 3a/3bꢀ1/2. Complex 3
/
To a solution of 1,3-dichloroacetone (1.003 g, 7.87
mmol) in deoxygenated CHCl3 (20 ml), bis(diphenyl-
phosphino)methane (dppm) (3.032 g, 7.87 mmol) was
added. This solution was refluxed under an Ar atmo-
sphere for 12 h. During this time a white solid
precipitated. After cooling, the solid was filtered,
washed with CHCl3 (5 ml) and Et2O (20 ml), air-dried
and identified as 1. Obtained: 2.658 g (70.3% yield).
Compound 1 crystallizes with 2.5 molecules of water,
which proved to be difficult to remove.
crystallized with 3 molecules of H2O. Repeated attempts
to eliminate them by heating were unsuccessful (decom-
position). Spontaneous crystallization from a concen-
trated dmso solution gave yellow crystals of 3b×
Anal. Calc. for C28H24Cl2OP2Pd×3OH2: C, 50.20; H,
4.51. Found: C, 50.02; H, 4.34%. MS (FABꢂ) [m/z,
(%)]: 616 (3%) [Mꢂ], 581 (40%) [(MꢁCl)ꢂ], 439 (100%)
[(Mꢁ
PdCl2)ꢂ]. IR (n, cmꢁ1): 1635 (nCꢀO), 302, 290
(nPdꢁCl). H NMR (dmso-d6, r.t.): d (ppm), 8.49Á
/3dmso.
/
/
/
/
1
/
7.25
3b), 5.54 (pseudoq, P2CH2, 3a,
15.5 Hz), 5.34 (pseudoq, broad, P2CH2,
(m, Ph, 3aꢂ
/
2JHH
:
/
2JPH
ꢀ
/
Anal. Calc. for [C28H25ClOP2]×
5.81. Found: C, 64.78; H, 5.49%. MS (FABꢂ
(%)]: 439 (100%) [(Mꢁ
Cl)ꢂ]. IR (n, cmꢁ1): 1587, 1568
7.53 (m,
14.4 Hz), 5.82 (d,
/
2.5H2O: C, 64.68; H,
2
3a, JHH
2
/) [m/z,
ꢀ
:
/
15.5 Hz, JPH
2JPH
ꢀ
/
12.6 Hz), 4.62 (t, PCH2CO,
13.8 Hz), 4.26 (pseudot, P2CHPd, 3b,
3b, 2JHH
2JPH
/
ꢀ
/
/
(nCꢀO). 1H NMR (dmso-d6, r.t.): d (ppm), 8.04Á
/
ꢀ5.8 Hz), 4.05 (s, broad, PCHPd, 3a), 3.64 (d,
/
20H, Ph), 6.20 (t, 2H, PCH2P, 2JPꢁH
ꢀ
/
2
PCHPd, 3b, JPH
2JHH 13.8 Hz, 2JPH
d6, r.t.): d (ppm), 18.4 (s, broad, 3a), 8.8, 7.7 (AB spin
ꢀ
/
9.9 Hz), 3.34 (dd, PCH2CO, 3b,
2
12.0 Hz). 31P{1H} NMR (dmso-
1H, Pꢀ
2JPꢁH
(ppm), 18.4 (s, broad, PCH2), 9.3 (s, broad, Pꢀ
13C{1H} NMR (dmso-d6, r.t): d (ppm), 170.1 (d, CO,
2JPC
11.1 Hz), 135.4 (s, Cpara, Ph), 134.5 (s, Cpara, Ph),
132.7 (d, Cmeta, Ph, 3JPC
10.4 Hz), 132.6 (d, Cmeta, Ph,
3JPC
10.0 Hz), 129.8 (d, Cortho, Ph, JPC
129.6 (d, Cortho, Ph, 2JPC
13.0 Hz), 121.0 (d, Cipso, Ph,
1JPC
95 Hz), 116.7 (d, Cipso, Ph, JPC
(dd, Pꢀ
PCH2, 1JPC
/
C(H), JPꢁH
ꢀ9.3 Hz), 5.10 (d, 2H, PCH2,
/
ꢀ
/
ꢀ
/
ꢀ
/
13.8 Hz). 31P{1H} NMR (dmso-d6, r.t.): d
CH).
2
system, 3b, JPP
ꢀ
11.3 Hz). 13C{1H} NMR (dmso-d6,
r.t.): d (ppm), 181.8 (s, CO, 3b), 167.8 (s, CO, 3a),
/
/
134.3Á
/
121.1 (m, Ph, 3aꢂ
/
3b), 32.6 (d, PCH2, 3b, 1JPC
ꢀ
/
ꢀ
/
1
51 Hz), 30.7 (d, PCH, 3a, JPC
ꢀ53.1 Hz), 22.4 (t,
/
ꢀ
/
1
P2CH2, 3a, JPC
1
52.9 Hz), 20.9 (d, PCH, 3b, JPC
2
ꢀ
/
ꢀ
/
ꢀ
/
ꢀ13.3 Hz),
/
1
54.9 Hz), ꢁ13.4 (t, P2CH, 3b, JPC
/
ꢀ38.9 Hz).
/
ꢀ
/
1
ꢀ
/
ꢀ
/
89 Hz), 70.0
9.5 Hz), 23.3 (d,
46.6 Hz), 12.3 (t, PCH2P, 1JPC
45.4 Hz).
1
3
5.6. Synthesis of 4
/
CH, JPC
ꢀ
/
103 Hz, JPC
ꢀ
/
ꢀ
/
ꢀ
/
To a suspension of 3 (0.165 g, 0.268 mmol) in NCMe
(20 ml), AgClO4 (0.111 g, 0.536 mmol) was added, and
the resulting mixture was stirred for 30 min with
exclusion of light. After the reaction time, the white
solid (AgCl) was filtered over Celite and the resulting
pale yellow solution was evaporated to dryness. The oily
residue was treated with Et2O (20 ml), giving 4 as a
white solid. Obtained: 0.184 g (83.1% yield). Molar ratio
5.4. Spectroscopic characterization of the mixture 2a/2b
To a suspension of 1 in CDCl3 (0.4 ml), NEt3 was
added until complete dissolution was obtained. The bis-
ylide 2a and the ylide-methanide 2b were obtained
instantaneously (1/2 molar ratio). The NMR measure-
ments were carried out 5 min after mixture (time for
locking and shimming).
4a/4bꢀ/1/2. Complex 4 was recrystallized from CH2Cl2/
Et2O, giving colorless crystals of 4×/1.25CH2Cl2. These
crystals were used for analytic and spectroscopic pur-
poses. The amount of solvent of crystallization was
quoted from the corresponding resonance in the 1H
NMR spectrum.
1H NMR (CDCl3, r.t.): d (ppm), 7.79Á
/
7.28 (m, Ph),
CH, 2a,
14.4 Hz,
3.85 (d, Pꢀ
2JPH
25.8 Hz), 3.36 (dd, Pꢀ
2JPH
/
CH, 2b, 2JPH
ꢀ
/
12.6 Hz), 3.73 (d, Pꢀ
/
ꢀ
/
/
C(H)P, 2b, 2JPH
ꢀ
/
2
ꢀ/2.4 Hz), 3.18 (d, PCH2, 2b, JPH
ꢀ12.0 Hz); the
/
Anal. Calc. for [C32H30Cl2N2O9P2Pd]×
/
1.25CH2Cl2: C,
42.84; H, 3.51; N, 3.00. Found: C, 42.68; H, 3.55; N,
resonance due to the PCH2P protons was not observed,
probably hidden by the [HNEt3]ꢂ signals. 31P{1H}
NMR (CDCl3, r.t.): d (ppm), 16.6, 11.4 (AB spin
2.95%. MS (FABꢂ
/
) [m/z, (%)]: 645 (100%) [(Mꢁ
/
2NCMeꢁ
/
ClO4)ꢂ]. IR (n, cmꢁ1): 2324, 2295 (nCN),
2
system, 2b, JPP
1
ꢀ
/
38.4 Hz), 8.9 (s, 2a).
1667 (nCꢀO). H NMR (CD2Cl2, r.t.): d (ppm), 8.21Á
/

L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á
/85
83
7.11 (m, Ph, 4aꢂ
/
4b), 5.35 (pseudoq, P2CH2, 4a,
15 Hz), 4.78 (pseudoq, broad, P2CH2,
2JPH
15 Hz), 4.72 (s, broad, P2CHPd, 4b),
Anal. Calc. for [C29H28Cl2P2]×
/
2H2O: C, 63.86; H,
2JHH
:
/
2JPH
ꢀ
/
5.91. Found: C, 63.70; H, 5.81%. MS (FABꢂ) [m/z,
/
2
4a, JHH
:
/
ꢀ
/
(%)]: 437 (100%) [(Mꢁ
/
Hꢁ
2Cl)ꢂ]. IR (n, cmꢁ1): 1645,
/
2
4.55 (pseudot, PCH2CO, 4b, JPH
4.08 (s, broad, PCHPd, 4a), 3.85 (d, PCHPd, 4b, 2JPH
7.2 Hz), 3.55 (dd, PCH2CO, 4b, 2JHH 13.5 Hz, 2JPH
17.7 Hz), 2.50, 2.17, 2.10 (3s, NCMe, 4aꢂ
4b). 31P{1H}
NMR (CD2Cl2, r.t.): d (ppm), 22.1 (s, broad, 4a), 17.3,
11.8 (2s, broad, 4b). 13C{1H} NMR (CD2Cl2, r.t.): d
:
/
2JHH
ꢀ/13.5 Hz),
1624 (nCꢀC), 1590 (Ph). 1H NMR (dmso-d6, r.t.): d
(ppm), 8.14 (m, 8H, Hortho, Ph), 7.70 (m, 4H, Hpara, Ph),
ꢀ
/
ꢀ
/
ꢀ
/
7.55 (m, 8H, Hmeta, Ph), 6.61 (t, 2H, P2CH2, 2JPH
ꢀ/15.5
/
Hz), 5.96 (s, 2H, ꢀ
/
CH2), 4.98 (d, 4H, PCH2, 2JPH
ꢀ/16.8
Hz). 31P{1H} NMR (dmso-d6, r.t.): d (ppm), 15.5.
13C{1H} NMR (dmso-d6, r.t.): d (ppm), 135.1 (s, Cpara
Ph), 132.9 (d, Cmeta, Ph, 3JPC
4.9 Hz), 129.7 (d, Cortho
Ph, 2JPC C, 2JPC
6.5 Hz), 127.5 (t, ꢀ
,
,
(ppm), 184.2 (s, CO, 4b), 173.1 (s, CO, 4a), 136.0Á
/
119.7
51.8
ꢀ
/
1
4b), 33.0 (d, PCH2, 4b, JPC
(m, Phꢂ
/
NC, 4aꢂ
/
ꢀ
/
ꢀ
/
/
ꢀ11 Hz), 126.9 (t,
/
1
Hz), 31.2 (d, PCH, 4a, JPC
3
1
ꢀ
/
48.3 Hz), 25.2 (t, P2CH2,
ꢀ
/
CH2, JPC
ꢀ
/
10 Hz), 117.8 (d, Cipso, Ph, JPC
ꢀ/94.3
1
4a, JPC
ꢀ
/
52.4 Hz), 3.3 (s, NCMe, 4aꢂ
/4b); the reso-
Hz), 26.9 (dd, PCH2, 1JPC
ꢀ
/
58.2 Hz, 3JPC
ꢀ
/
9 Hz), 13.9
1
(t, P2CH2, JPC
nances corresponding to one ylide carbon and to the
methanide carbon (for 4b) were not observed.
ꢀ41 Hz).
/
5.9. Spectroscopic characterization of 6?
5.7. Synthesis of 5
To a suspension of 6 in CDCl3 (0.4 ml), NEt3 was
added until complete dissolution was attained. The
ylide-phosphonium salt 6? was obtained instanta-
neously. The NMR measurements were carried out 5
min after mixture (time for locking and shimming).
To a suspension of 3 (0.271 g, 0.440 mmol) in acetone
(15 ml), AgClO4 (0.182 g, 0.880 mmol) was added, and
the resulting mixture was stirred at r.t. for 30 min with
exclusion of light. After the reaction time, the white
solid (AgCl) was filtered and discarded. To the resulting
pale yellow solution pyridine (0.57 ml, 1.8 mmol) was
added, and stirring was continued for 30 min. During
this time, 5 precipitated as a white solid, which was
filtered, washed with Et2O and air dried. Obtained:
1H NMR (CDCl3, r.t.): d (ppm), 7.76Á
ortho, Ph), 7.56Á7.45 (m, 12H, Hmeta Hpara, Ph), 5.00
3.9 Hz), 3.84 (d, 4H, PCH2,
/
7.69 (m, 8H,
H
/
ꢂ
/
4
(t, 2H, ꢀ
2JPH
16.8 Hz), 1.30 (t, 1H, P2CH, JPH
31P{1H} NMR (CDCl3, r.t.): d (ppm), 15.6 (s). 13C{1H}
NMR (CDCl3, r.t.): d (ppm), 134.7Á127.2 (m, Ph),
125.4 (t, ꢀ
Hz), 119.4 (d, Cipso, Ph, JPC
1JPC
58.5 Hz), ꢁ3.7 (t, P2CH, JPC
/
CH2, JPH
ꢀ
/
2
ꢀ
/
ꢀ4.2 Hz).
/
/
0.196 g (49.4% yield). Molar ratio 5a/5bꢀ3/1. The
/
2
3
/
C, JPC
ꢀ
/
10 Hz), 120.8 (t, ꢀ
/
CH2, JPC
ꢀ10
/
evaporation of the acetone solution gave an intractable
residue, from which no identifiable products could be
obtained.
1
ꢀ
/
84 Hz), 33.0 (d, PCH2,
1
ꢀ
/
/
ꢀ108.4 Hz).
/
Anal. Calc. for C38H34Cl2N2O9P2Pd: C, 50.60; H,
3.80; N, 3.11. Found: C, 50.69; H, 3.82; N, 3.29%. MS
5.10. Synthesis of 7
(FABꢂ
(60%) [(Mꢁ
/
) [m/z, (%)]: 803 (15%) [(Mꢁ
/
ClO4)ꢂ], 724
ClO4ꢁ
To a suspension of 6 (0.250 g, 0.49 mmol) in dry THF
(20 ml), LitBu (0.72 ml of a 1.5 M solution, 1.1 mmol)
was added, giving, in few seconds, an intense orange
solution. This solution was stirred at r.t. for 15 min, and
then cooled on an ice bath. PdCl2(NCMe)2 (0.123 g,
0.49 mmol) was added to the cool solution, the mixture
was stirred for 30 min, and then the bath was removed
and the solvent was evaporated to dryness. The residue
/
ClO4ꢁ
/
py)ꢂ], 645 (100%) [(Mꢁ
/
/
2py)ꢂ]. IR (n, cmꢁ1): 1658 (nCꢀO), 1607 (py). 1H
NMR (dmso-d6, r.t.): d (ppm), 8.48 (s, br, Hortho, py,
5a), 7.88Á
/
7.24 (m, Phꢂ
/
py, 5aꢂ
15.3 Hz), 5.63 (pseudoq,
2JPH
15.3 Hz), 5.29 (pseu-
2JHH
15.0 Hz), 4.88 (s,
/
5b), 6.33 (pseudoq,
2
P2CH2, 5a, JHH
:
/
2JPH
ꢀ
/
2
broad, P2CH2, 5a, JHH
2
dot, PCH2CO, 5b, JPH
:
/
ꢀ
/
:
/
ꢀ
/
broad, PCHPd, 5b), 4.60 (s, broad, PCHPd, 5a), 3.90
(s, broad, PCHPd, 5b), 3.84 (pseudot, PCH2CO, 5b,
was extracted with CH2Cl2 (2ꢃ
combined yellow solution was evaporated to small
volume (:2 ml). By Et2O addition (20 ml) and stirring,
7 was obtained as a yellowÁorange solid, which was
/10 ml), filtered, and the
2JHH
d (ppm), 20.9 (s, 5a), 13.7, 12.2 (2s, broad, 5b).
:
/
2JPH
ꢀ
15.0 Hz). 31P{1H} NMR (dmso-d6, r.t.):
/
/
/
filtered, washed with Et2O (10 ml) and dried. Obtained:
0.239 g (79.3% yield).
Anal. Calc. for [C29H26Cl2P2Pd]: C, 56.75; H, 4.27.
5.8. Synthesis of 6
To a solution of dppm (0.500 g, 1.30 mmol) in 15 ml
Found: C, 56.68; H, 4.25%. MS (FABꢂ
/
) [m/z, (%)]: 577
Ph), 291,
273 (nPdꢁCl). H NMR (CD2Cl2, r.t.): d (ppm), 8.58Á
of deoxygenated 1,2-dichloroethane, H2Cꢀ
/C(CH2Cl)2
(50%) [(Mꢁ
/
Cl)ꢂ]. IR (n, cmꢁ1): 1560 (nCꢀC
ꢂ
/
1
was added (0.150 ml, 1.30 mmol). This solution was
refluxed (Ar atmosphere) for 24 h. Once cooled, the
white precipitate of 6 was filtered, washed with Et2O (20
ml) and dried in vacuo. Obtained: 0.329 g (50% yield).
The product 6 crystallizes with two molecules of H2O.
/
2
6.89 (m, 20H, Ph), 5.75 (d, 1H, ꢀ
/
C(H)P, JPH
Hz), 2.72 (s, broad, 1H, P2C(H)Pd), 2.67 (d, 1H,
ꢀ20.4
/
2
PC(H)Pd, JPH
ꢀ
10.2 Hz), 2.48 (s, 3H, Me). 31P{1H}
NMR (CD2Cl2, r.t.): d (ppm), 10.2 (s, PPh2), 7.7 (s,
/

84
L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á85
/
PPh2). 13C{1H} NMR (CD2Cl2, r.t.): d (ppm), 172.2 (s,
CHCl3, the interstitial chloroform molecule was found
to be disordered in such a way that the carbon atom and
one chlorine could be refined with full occupancy, but
that the other two chlorine atoms were disordered over
more than one site each. In order to achieve the best fit
to the average electron density observed by X-ray
diffraction, we modeled the latter two chlorine atoms
as three partially occupied sites each, maintaining
proper stoichiometry. Given the disorder, however, we
do not believe that the geometric parameters derived for
this moiety are useful descriptors for the shape of the
chloroform molecule. Crystallographic calculations
were done on an AlphaStation (OPEN/VMS V6.2).
1
CH, JPC
ꢀ
/
C), 135.0Á
/
122.0 (m, Ph), 96.5 (dd, ꢀ
/
ꢀ
17.0 Hz,
/
93.5
3
3
Hz, JPC
3JPC
9.1 Hz), 6.3 (dd, C-ylide, PdC(H)P, JPC
Hz, 3JPC
7.7 Hz), ꢁ17.5 (dd, C-methanide, PdC(H)P2,
1JPC
52.1 Hz, JPC 40.0 Hz).
ꢀ/7.2 Hz), 29.1 (dd, CH3, JPC
ꢀ
/
1
ꢀ
/
ꢀ57.8
/
ꢀ
/
/
1
ꢀ
/
ꢀ
/
5.11. X-ray crystallography
Crystals of the complex 3b×/3dmso of adequate quality
for X-ray measurements were obtained by spontaneous
crystallization from a concentrated dmso solution of the
crude complex 3×
/
3H2O. Crystals of 7×
/
CHCl3 of ade-
quate quality for X-ray mesurements were obtained by
slow vapour diffusion of Et2O into a CHCl3 solution of
complex 7. One crystal of each compound was mounted
at the end of a quartz fiber and covered with epoxy.
6. Supplementary material
Tables giving complete data collection parameters,
atomic coordinates, complete bond distances and angles
5.11.1. Data collection
A single crystal of dimensions 0.39ꢃ
(3b×3dmso) or 0.21ꢃ0.15ꢃ0.04 mm (7×
mounted in a random orientation. In both cases, data
collection was performed at Tꢀ 100 8C on a Bruker
Smart CCD diffractometer using graphite monochro-
/
0.25ꢃ
/
0.16 mm
and thermal parameters for 3b×
/
3dmso and 7×/CHCl3
/
/
/
/CHCl3) was
have been deposited with the Cambridge Crystallo-
graphic Data Centre, CCDC Nos. 183568 and 183569
/
ꢁ
/
for 3b×
/
3dmso and 7×
/
CHCl3, respectively. Copies of this
information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2
˚
mated Mo Ka radiation (lꢀ
of data was collected based on three v-scan runs
(starting vꢀ 308) at values fꢀ0, 90 and 1808 with
the detector at 2uꢀ308. For each of these runs, frames
/
0.71073 A). A hemisphere
1EZ, UK (fax: ꢂ44-1223-336-033; e-mail: deposit@
/
/
ꢁ
/
/
ccdc.cam.uk or www: http://www.ccdc.cam.ac.uk).
/
(606, 435 and 230, respectively) were collected at 0.38
intervals and 10 s per frame. The diffraction frames were
integrated using the program SAINT [23] and the
integrated intensities were corrected for absorption
with SADABS [24].
Acknowledgements
Funding by the DGESIC (Spain, projects PB98-1593
and PB98-1595-C02-01) is gratefully acknowledged, and
we thank Professor J. Fornie´s for invaluable logistical
support.
5.11.2. Structure solution and refinement
The structures were solved and developed by Patter-
son and Fourier methods [25]. 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 (complex 7), which were first located in a
local slant-Fourier calculation and then refined as riding
References
[1] A.W. Johnson, Ylides and Imines of Phosphorous, (Chapter 14
and references therein), Wiley, New York, 1993.
[2] O.I. Kolodiazhnyi, Phosphorus Ylides, Chemistry and Applica-
tion in Organic Synthesis, Wiley-VCH, Weinheim, 1999.
[3] U. Belluco, R.A. Michelin, M. Mozzon, R. Bertani, G. Facchin,
L. Zanotto, L. Pandolfo, J. Organomet. Chem. 557 (1998) 37.
atoms with the torsion angles about the Cꢁ
/
C(methyl)
bonds treated as variables. Each hydrogen atom was
assigned an isotropic displacement parameter equal to
1.2 times the equivalent isotropic displacement para-
meter of its parent atom. The structures were refined to
Fo2, and no reflections were omitted in the least-squares
[4] (a) E. Fluck, K. Bieger, G. Heckmann, B. Neumuller, J.
¨
Organomet. Chem. 459 (1993) 73;
(b) S. Plank, G. Heckmann, W. Schwarz, B. Neumuller, E. Fluck,
¨
Z. Anorg. Allg. Chem. 625 (1999) 1712;
calculations [26]. During the refinement of 3b×
/3dmso
(c) G. Heckmann, S. Plank, W. Schwarz, E. Fluck, Z. Anorg.
Allg. Chem. 625 (1999) 773.
[5] (a) H. Schmidbaur, C. Paschalidis, O. Steigelmann, G. Muller,
¨
one of the solvent regions was found to be so severely
disordered that we were not able to build up a sensible
model for it. The effects of this solvent were removed by
the SQUEEZE algorithm of the program PLATON [27].
One of the other solvent regions was also disordered,
but in this case it was possible to refine a model in which
Angew. Chem., Int. Ed. Engl. 29 (1990) 516 (and references
therein);
(b) H. Schmidbaur, C. Paschalidis, O. Steigelmann, G. Muller,
¨
Angew. Chem., Int. Ed. Engl. 28 (1989) 1700.
[6] E. Fluck, B. Neumuller, G. Heckmann, W. Plass, P.G. Jones,
¨
two dmso congeners share the site. In the structure of 7×
/
New J. Chem. 13 (1989) 383.

L.R. Falvello et al. / Inorganica Chimica Acta 347 (2003) 75Á
/85
85
[7] H. Schmidbaur, T. Costa, B. Milewski-Mahrla, F.H. Kohler, Y.-
(b) J. Vicente, M.T. Chicote, I. Saura-Llamas, M.J. Lo´pez-
Mun˜oz, P.G. Jones, J. Chem. Soc., Dalton Trans. (1990) 3683;
(c) A. Jouaiti, M. Geoffroy, G. Bernardinelli, Chem. Commun.
(1996) 437;
¨
H. Tsay, C. Kruger, J. Abart, F.E. Wagner, Organometallics 1
¨
(1982) 1266.
[8] H. Schmidbaur, T. Costa, B. Milewski-Mahrla, Chem. Ber. 114
(1981) 1428.
[9] M. Luckoff, K. Dimroth, Angew. Chem., Int. Ed. Engl. 15 (1976)
¨
(d) J. Vicente, M.T. Chicote, M.C. Lagunas, P.G. Jones, E.
Bembenek, Organometallics 13 (1994) 1243.
503.
[10] D.G. Hewitt, in: A.R. Katrizky, C.W. Rees, E.F.V. Scriven
(Eds.), Comprehensive Heterocyclic Chemistry II, vol. 5, Perga-
[20] F.H. Allen, O. Kennard, D.G. Watson, L. Brammer, A.G. Orpen,
R. Taylor, J. Chem. Soc., Perkin Trans. 2 (1987) S1.
[21] (a) L.R. Falvello, S. Ferna´ndez, R. Navarro, A. Rueda, E.P.
Urriolabeitia, Inorg. Chem. 37 (1998) 6007;
mon, Oxford, 1996, pp. 639Á668.
/
[11] G. Maerkl, P. Kreitmeier, in: A.R. Katrizky, C.W. Rees, E.F.V.
Scriven (Eds.), Comprehensive Heterocyclic Chemistry II, vol. 6,
(b) L.R. Falvello, S. Ferna´ndez, R. Navarro, A. Rueda, E.P.
Urriolabeitia, Organometallics 17 (1998) 5887.
Pergamon, Oxford, 1996, pp. 1019Á
/
1071.
[22] G.K. Anderson, M. Lin, Inorganic Syntheses 28 (1990) 60.
[23] SAINT Version 5.0, Bruker Analytical X-ray Systems, Madison,
WI.
[12] K. Dimroth, Acc. Chem. Res. 15 (1982) 58.
[13] R. Navarro, E.P. Urriolabeitia, J. Chem. Soc., Dalton Trans.
(1999) 4111.
[24] G.M. Sheldrick, SADABS, Empirical absorption correction pro-
gram, University of Gottingen, Gottingen, Germany, 1996.
¨ ¨
[14] J.A. Ford, C.V. Wilson, J. Org. Chem. 26 (1961) 1433.
[15] D.B. Denney, J. Song, J. Org. Chem. 29 (1964) 495.
[16] L.R. Falvello, S. Ferna´ndez, C. Larraz, R. Llusar, R. Navarro,
E.P. Urriolabeitia, Organometallics 20 (2001) 1424.
[17] J. Vicente, M.T. Chicote, I. Sauras-Llamas, P.G. Jones, K.
[25] G.M. Sheldrick, SHELXS-86, Acta Crystallogr. A 46 (1990) 467.
[26] G.M. Sheldrick, SHELXL-97: FORTRAN program for the refine-
ment of crystal structures from diffraction data, Gottingen
¨
University, Gottingen, Germany, 1997. Molecular graphics were
¨
done using the commercial package SHELXTL-PLUS, Release 5.05/
Meyer-Base, C.F. Erdbrugger, Organometallics 7 (1988) 997.
¨
¨
[18] L.R. Falvello, S. Ferna´ndez, R. Navarro, E.P. Urriolabeitia,
Inorg. Chem. 38 (1999) 2455.
V, Siemens Analytical X-ray Instruments, Inc., Madison, I, 1996.
[27] (a) P. van der Sluis, A.L. Spek, SQUEEZE, Acta Crystallogr. A46
(1990) 194;
[19] (a) H. Takahashi, Y. Oosawa, A. Kobayashi, T. Saito, Y. Sasaki,
Bull. Chem. Soc. Jpn. 50 (1977) 1771;
(b) A.L. Spek, PLATON, Acta Crystallogr. A46 (1990) C-34.