CP/MAS NMR and X-ray crystallographic characterization of trans-PdX2(PPh2vinyl)2 (X = Cl, I); UV and Et2O·BF3 reaction studies, including the formation of [Pd(μ-Cl)(PPh2vinyl)2]<

Article abstract of DOI:10.1139/v00-101

The complexes PdCl₂(PPh₂vinyl)₂ PdI₂(PPh₂vinyl)₂ have been prepared and crystallographically characterized as their trans square planar isomers. Trans-PdCl₂(PPh₂vinyl)

Full text of DOI:10.1139/v00-101

1073
CP/MAS NMR and X-ray crystallographic
characterization of trans-PdX2(PPh2vinyl)2 (X = Cl, I);
UV and Et2O·BF3 reaction studies, including the
formation of [Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2
Michael B. Hursthouse, David G. Kelly, Mark E. Light, and Andrew J. Toner
Abstract: The complexes PdCl2(PPh2vinyl)2 and PdI2(PPh2vinyl)2 have been prepared and crystallographically
characterized as their trans square planar isomers. Trans-PdCl2(PPh2vinyl)2 exists in a centrosymmetric structure with a
planar PdCl2P2 core whereas trans-PdI2(PPh2vinyl)2 shows no local Pd-centred symmetry and significant distortion of
the PdI2P2 core from planarity. Crystallographic data is in accord with the 31P{1H} CP/MAS NMR spectra of the two
complexes, which display a single resonance for the chloro-complex and two resonances for the iodo-complex. UV
irradiation of CH2Cl2 solutions of PdCl2(PPh2vinyl)2 followed by re-dissolution in CDCl3 indicates no permanent
chemical change. However, post-irradiation CP/MAS 31P{1H} NMR spectroscopy demonstrates the presence of
trans-PdCl2(PPh2vinyl)2 in two solid state structures, plus cis-PdCl2(PPh2vinyl)2. PdI2(PPh2vinyl)2 exists only in its
trans form in both solid state and solution. Irradiation results in phosphine displacement and the formation of
sym-[PdI2(PPh2vinyl)]2 and free phosphine, the latter being characterized as Ph2P(O)vinyl following aerobic oxidation.
PdCl2(PPh2vinyl)2 reacts in the presence of Et2O·BF3 to afford [Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2 whereas PdI2(PPh2vinyl)2
is recovered in 95% yield, with the remaining material undergoing phosphine abstraction to form sym-[PdI2(PPh2vinyl)]2.
Key words: palladium, phosphine, alkene, isomerization, CP/MAS.
Résumé : On a préparé les complexes PdCl2(PPh2vinyl)2 et PdI2(PPh2vinyl)2 et sur la base de la cristallographie, on a
établi qu’il s’agit des isomères plans carrés trans. Le trans-PdCl2(PPh2vinyl)2 existe dans une structure
centrosymétrique comportant une unité centrale PdCl2P2 plane alors que le trans-PdI2(PPh2vinyl)2 est fortement
déformé par rapport à la planéité. Les données cristallographiques sont en accord avec le spectre RMN CP/MAS du
31P{1H} des deux complexes qui ne présentent qu’une seule résonance pour le complexe chloré et deux résonances
pour le complexe iodé. L’irradiation UV de solutions de CH2Cl2 du complexe PdCl2(PPh2vinyl)2 suivie d’une
redissolution dans le CDCl3 indique qu’il n’y a pas de changement chimique permanent. Toutefois, la spectroscopie
RMN CP/MAS du 31P{1H} démontre la présence de trans-PdI2(PPh2vinyl)2 dans deux structures à l’état solide en plus
de cis-PdI2(PPh2vinyl)2. Le PdI2(PPh2vinyl)2 n’existe que dans sa forme trans tant à l’état solide qu’en solution.
L’irradiation provoque un déplacement de la phosphine et la formation de sym-[PdI2(PPh2vinyl)]2 et de phosphine libre;
cette dernière est caractérisée sous la forme de Ph2P(O)vinyl après une oxydation aérobique. Le trans-PdCl2(PPh2vinyl)2
réagit en présence de Et2O·BF5 pour conduire à la formation de [Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2 alors que le PdI2(PPh2vinyl)2
est récupéré avec un rendement de 95%, le reste du produit subissant une abstraction de phosphine avec formation de
la sym-[PdI2(PPh2vinyl)]2.
Mots clés : palladium, phosphine, alcène, isomérisation, CP/MAS.
[Traduit par la Rédaction] Hursthouse et al. 1080
Introduction
Increasing interest exists in the formation of high molecu-
lar weight materials from metal complexes and the incorpo-
Received February 7, 2000. Published on the NRC Research
ration of such complexes into organic polymers. Pendant
Press website on August 11, 2000.
alkene moieties incorporated into phosphine ligands and
their complexes have demonstrated polymerization in the
presence of UV radiation and Lewis acids (1, 2). The poten-
tial for similar polymerization or alternative metal-centred
reaction pathways is assessed in the present work for palla-
dium(II) complexed diphenylvinylphosphine. Palladium(II)
readily forms PdX2P2 (X = halide, P = tertiary phosphine)
complexes with monodentate and bidentate phosphines.
These complexes have formed the focus of numerous studies
as a vehicle for probing cis/trans isomerization (3) and
M.B. Hursthouse and M.E. Light. Department of Chemistry,
University of Southampton, Highfield, Southampton,
SO17 1BJ, U.K.
D.G. Kelly1 and A.J. Toner. Department of Chemistry and
Materials, The Manchester Metropolitan University, Chester
Street, Manchester M1 5GD, U.K.
1Author to whom correspondence may be addressed.
Telephone: (+44) 161 247 1425. Fax: (+44) 161 247 6357.
e-mail: d.g.kelly@mmu.ac.uk
Can. J. Chem. 78: 1073–1080 (2000)
© 2000 NRC Canada

1074
Can. J. Chem. Vol. 78, 2000
Fig. 1. Single crystal X-ray diffraction structure of trans-PdCl2(PPh2vinyl)2.
ligand/anion exchange processes (4), and as potential
stoichiometric and catalytic reagents in synthesis (5). The
principal modes of characterization have been solution
31P{1H} NMR spectroscopy and single crystal X-ray diffrac-
tion studies. The former technique demonstrates that
monodentate phosphine complexes generally exist as
cis/trans mixtures in solution, although modification of P
and X can lead to the trans isomer being overwhelmingly
thermodynamically favored (6). Crystallization generally
leads to the isolation of trans complexes; indeed 45 of the
55 reported PdX2P2 single crystal X-ray diffraction struc-
tures of monodentate phosphine complexes are of the trans
isomer.2 Solid state distortion from square planar geometries
in these crystallographic studies is known but is not univer-
sal. In contrast, such distortion is not observed by solution
31P{1H} NMR spectroscopy.
Cross-polarization magic-angle-spinning (CP/MAS) NMR
spectroscopy offers an increasingly available and comple-
mentary characterization technique that probes the solid
state structure of non-crystalline materials. The study of
solid samples by conventional NMR apparatus and experi-
ments yields at best broad signals or a rolling baseline. Two
principal factors contribute to this uninformative data; di-
pole-dipole nucleur interactions and chemical shift aniso-
tropy (CSA). The former is removed in solution by
molecular motion, which is sufficiently rapid to afford an av-
eraged molecular orientation and thus zero local field. The
effect of CSA, the directional influence of chemical bonds
on nucleur shielding, is reduced to zero by the same motion
in solution. Both factors vary in magnitude as a function of
3 cos2 θ – 1, where θ is the orientation to the applied field.
Thus, spinning samples at a frequency larger than the CSA
linewidth (usually a few kilohertz), and at an angle where
the term 3 cos2 θ – 1 becomes zero (54° 44′) allows the ob-
servation of sharp solid state spectra. Such ‘magic angle
spinning’ when coupled with the sensitivity enhancement of
cross polarization provides effective and informative solid
state NMR data. In the present study we have investigated
the solid state and solution chemistry of the PdX2P2 com-
plexes (X = Cl, I; P = PPh2vinyl) as part of our recent stud-
ies of bifunctional phosphine/alkene ligands (7, 8). The
reported solution NMR data for these complexes are supple-
mented here by crystallographic characterization, and by
CP/MAS NMR spectroscopy (9). Reactivity initiated by UV
irradiation and in the presence of Lewis acids has also been
considered.
Results and discussion
Synthesis and characterization of PdX2(PPh2vinyl)2
(X = Cl, I)
Synthesis of PdCl2P2 complexes (P = tertiary phosphine)
is well established and readily achieved by the reaction of
PdCl2(PhCN)2 with two equivalents of tertiary phosphine.
Iodide complexes may be isolated in high yield by metathe-
sis of the respective chloride with excess aqueous NaI (9).
The utilization of such synthetic routes and subsequent
recrystallization from diethylether–dichloromethane affords
crystalline PdCl2(PPh2vinyl)2 and PdI2(PPh2vinyl)2 in high
yield. Crystals of both PdCl2(PPh2vinyl)2 and PdI2(PPh2vi-
nyl)2 proved suitable for single crystal X-ray diffraction
studies, with structure elucidation demonstrating the forma-
tion of trans square planar PdCl2(PPh2vinyl)2 and
PdI2(PPh2vinyl)2 (Figs. 1 and 2, respectively).
Metal-centred bond lengths and angles for PdCl2(PPh2vi-
nyl)2 indicate a centrosymmetric and therefore planar
PdCl2P2 core, with Cl-Pd-Cl and P-Pd-P vectors being al-
most orthogonal (Table 1). In contrast, no local Pd-centred
2 CCDC Data Base Search. Cambridge, U.K. December 1999.
© 2000 NRC Canada

Hursthouse et al.
1075
Fig. 2. Single crystal X-ray diffraction structure of trans-PdI2(PPh2vinyl)2.
Table 1. Bond lengths and angles for trans-PdCl2(PPh2vinyl)2 and trans-PdI2(PPh2vinyl)2.
Bond lengths (Å)
and angles (°)a
trans-PdCl2-
(PPh2vinyl)2
trans-PdI2-
(PPh2vinyl)2
[Pd(µ-Cl)(PPh2-
vinyl)2]2[BF4]2
Pd—X(1)
Pd—X(2)
Pd—P(1)
Pd—P(2)
C(1)—C(2)
C(15)—C(16)
X-Pd-X
2.2979(5)
—
2.3284(5)
—
1.303(4)
—
180.0
180.0
90.967(19)
—
2.5938(4)
2.5959(4)
2.3336(13)
2.3324(13)
1.287(8)
2.3882(11)
2.3927(10)
2.2742(11)
2.2599(12)
1.306(7)
1.303(6)
84.27(4)
93.02(4)
90.79(4)
1.294(8)
169.78(2)
175.80(5)
88.39(3)
91.75(3)
126.7(5)
P-Pd-P
X(1)-Pd-P(1)
X(1)-Pd-P(2)
P(1)-C(1)-C(2)
P(2)-C(15)-C(16)
175.14(4)
125.6(4)
122.1(4)
126.0(2)
—
126.6(5)
aX = Cl, I.
symmetry is observed for PdI2(PPh2vinyl)2. Moreover, there
are significant distortions from planarity for the PdI2P2 core
and non-equivalence of both iodide and phosphine moieties.
The presence and absence of local symmetry between the
chloride and iodide complexes may be attributed to the rela-
tive ligand field splitting contributions of the respective an-
ions. Solution 31P{1H} NMR spectroscopy is not
representative of either trans solid state structure. For the
former complex, this is due to the rapid establishment of cis-
trans equilibria. Whilst for the latter thermal energy is suffi-
cient to allow rapid exchange on the NMR time-scale be-
tween inequivalent phosphines resulting in the observation
of a single solution resonance for the two ligands, Table 2.
However, CP/MAS 31P{1H} NMR spectroscopy does readily
characterize the two solid state structures affording a single
resonance for the centrosymmetric trans-PdCl2(PPh2vinyl)2
and two resonances for the asymmetric trans-PdI2(PPh2vi-
nyl)2. In both cases, the observed chemical shifts are similar
to those assigned to the solution resonances of the trans-
PdX2(PPh2vinyl)2 complexes, Table 2. 13C{1H} CP/MAS
NMR spectroscopy has been successfully employed in the
characterization of other palladium(II) phosphines (10).
Such spectra were recorded here for both trans complexes.
However, it is apparent from solution 13C{1H} NMR spec-
troscopy that phenyl and vinyl 13C{1H} resonances lie
within the same region and display significant 13C–31P cou-
pling. This feature, along with the additional complications
of solid state line broadening, plus non-equivalence for the
phosphine ligands of PdI2(PPh2vinyl)2, results in extensively
overlaid resonances for which deconvolution and assignment
are unreliable.
UV irradiation of PdX2(PPh2vinyl)2 (X = Cl, I)
The solution irradiation of PdX2(PPh2vinyl)2 complexes
offers three principal routes of reactivity. UV absorbance
followed by relaxation to the kinetically favored cis isomer
may occur to afford trans-cis isomerization (11). Alterna-
tively, short wavelength UV activation of alkene moieties
© 2000 NRC Canada

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Can. J. Chem. Vol. 78, 2000
Table 2. CP/MAS 31P{1H} NMR data for trans-PdCl2(PPh2vinyl)2, and trans-PdI2(PPh2vinyl)2 and for the same complexes after UV
irradiation.
Complex
Treatment
δ
31P CP/MAS
Assignmenta
δ
31P CDCl3
Assignmenta
trans-PdCl2(PPh2vinyl)2
Pre-irradiation
14.6
Symmetrical trans-PdCl2L2P1
13.6
21.8
13.6
trans-PdCl2L2
cis-PdCl2L2
trans-PdCl2L2
trans-PdCl2(PPh2vinyl)2
Post-irradiation
14.5
16.3
24.2, 31.6
5.4, 7.8
5.4, 7.6
22.9
Symmetrical trans-PdCl2L2 P1
Symmetrical trans-PdCl2L2
Asymmetric cis-PdCl2L2
Asymmetric trans-PdI2L2 P1
Asymmetric trans-PdI2L2 P1
Ph2P(O)vinyl
21.8
4.2
4.2
22.9
26.9
cis-PdCl2L2
trans-PdI2L2
trans-PdI2L2
Ph2P(O)vinyl
[PdI2L]2
trans-PdI2(PPh2vinyl)2
trans-PdI2(PPh2vinyl)2
Pre-irradiation
Post-irradiation
28.1, 30.3
Asymmetric [PdI2L]2
aL = PPh2vinyl
Fig. 3. CP/MAS 31P{1H} NMR spectra of trans-PdCl2(PPh2vinyl)2 before and after UV irradiation.
can produce oligomerization or polymerization (1), while
homolytic or heterolytic bond cleavage may result in gener-
alized or specific bond cleavage.3 The significance of these
various factors can be elucidated by comparison of pre- and
post-irradiation solution and solid state NMR data (Table 2).
in the extensively coupled vinylic protons associated with
cis and trans PdCl2(PPh2vinyl)2. Moreover, no upfield reso-
nances are observed which might be assigned to polyvinyl
moieties. Solution 31P{1H} NMR spectroscopy also displays
resonances that can be assigned to cis and trans
PdCl2(PPh2vinyl)2, with no additional features (Table 2).
Thus, it may be concluded that any new solid state feature
observed in the post-irradiation CP/MAS 31P{1H} NMR
spectrum of PdCl2(PPh2vinyl)2 corresponds to cis and trans
isomers of this complex (Fig. 3). Three new peaks are ob-
served in the CP/MAS 31P{1H} NMR spectrum at 16.3,
24.0, and 31.5 ppm. The former may be assigned to a crys-
tallization of trans-PdCl2(PPh2vinyl)2 in an alternative space
group to that crystallographically characterized here; a
feature which has been observed for other palladium(II)
and platinum(II) complexes (12, 13). Consideration of the
resonances at 24.0 and 31.5 ppm in isolation is problematic
because, in addition to cis-[PdCl2P2] complexes, other spe-
cies such as phosphine oxides afford similar chemical shifts.
However, because only cis and trans PdCl2(PPh2vinyl)2 are
Irradiation of ca. 10–1
M
CH2Cl2 solutions of
PdCl2(PPh2vinyl)2 and PdI2(PPh2vinyl)2 using wavelengths
of λ ≥ 200nm results in the rapid precipitation of palladium
containing materials. Precipitation results from the rapid sol-
vent heating associated with the relaxation of excited states
through vibrational processes. Where appropriate the forma-
tion of cis-[PdCl2P2] and sym-[PdI2P]2, which are recog-
nized to be of lower solubility than the corresponding trans-
[PdX2P2], may also be significant (6, 10, 11). Decanting re-
sidual solvent after ca. 2 min irradiation followed by drying
in vacuo affords a 95% yield (wt/wt) of materials slightly
darkened from the respective yellow and red colors of the
initial complexes. Consideration of the post-irradiation NMR
spectrum of PdCl2(PPh2vinyl)2 affords the following obser-
1
vations. Solution H NMR spectroscopy indicates no change
3 M. Edge, P. Faulds, D.G. Kelly, A. McMahon, G.C. Ranger, and D. Turner. Eur. Polym. J. manuscript 214/99, in press.
© 2000 NRC Canada

Hursthouse et al.
1077
Fig. 4. CP/MAS 31P{1H} NMR spectra of trans-PdI2(PPh2vinyl)2 before and after UV irradiation.
1
Table 3. 31P{1H}, 13C{1H}, and H NMR data for Ph2P(O)vinyl.
Scheme 1. Reactivity of PdX2(PPh2vinyl)2 on irradiation and in
the presence of Et2O·BF3.
NMR nucleus
Positiona
δ (ppm)
Coupling(Hz)
31P{1H}
23.3
6.68
6.31
6.27
7.20–7.55
131.65
135.04
132.80
131.75
128.97
132.26
1H
Ha
Hb
Hc
Ph
α
β
i (ipso)
o (ortho)
m (meta)
p (para)
12.5,b 18.7,c 24.5e
12.5,b 1.8,c 41.0e
18.7,c 1.8,d 22.3e
multiplet
96.5f
singlet
106.2f
9.7f
13C{1H}
31P{1H} NMR spectrum. Formation of cis-PdI2(PPh2vinyl)2
is unlikely due to the relative instability of this isomer, which
does not form by the solution equilibration of trans-
PdI2(PPh2vinyl)2. Moreover, kinetically slow isomerization
of such an apparently thermodynamically unstable cis spe-
cies may also be excluded by the static intensities of
31P{1H} solution NMR resonances over ca. 7 d. Thus, these
new resonances may be assigned to reaction, rather than
isomerization products. 1H NMR spectroscopy again ex-
cludes polymerization products by the absence of upfield
resonances. However, extraction of irradiated material with
hexane affords identical 31P{1H} and 1H NMR data to
Ph2P(O)vinyl samples obtained by direct PPh2vinyl oxida-
tion (Table 3). Thus, it may be suggested that the relaxation
of excited species can result in Pd—P cleavage and the sub-
sequent aerobic oxidation of free phosphine (14). Extraction
of Ph2P(O)vinyl, followed by recrystallization of the remain-
ing material from Et2O–CH2Cl2 results in the preferential
precipitation of deep red sym-[PdI2(PPh2vinyl)]2. The latter
may be manually separated from traces of the paler
trans-PdI2(PPh2vinyl)2. Elemental analysis and comparison
with published NMR data confirm the formation of sym-
[PdI2(PPh2vinyl)]2 (15) (Scheme 1).
12.2f
2.5f
a
Ha
Ph 2
Hb
Hc
P >C=C<
b 3
c 3
d 3
e n
J .
ab
J .
ac
J .
bc
J
.
PH
f n
J
.
CP
observed on re-dissolution these solid state resonances must
be assigned to an unsymmetrical cis-PdCl2(PPh2vinyl)2 spe-
cies. While these solid state chemical shifts lie downfield by
as much as 10 ppm from solution values, similar movements
have been observed in comparable palladium(II) systems (11).
Because conventional concentration and crystallization pro-
cesses yield trans-PdCl2(PPh2vinyl)2, irradiation may be viewed as
enhancing the solid-state concentration of cis-PdCl2(PPh2vinyl)2.
Irradiation of trans-PdI2(PPh2vinyl)2 affords a material for
which CP/MAS 31P{1H} resonances at 7.0 and 5.3 ppm are
observed which are representative of the original complex.
New resonances occur at 23.0, 27.5, and 29.8 ppm (Fig. 4).
Unlike the additional post-irradiation resonances of
PdCl2(PPh2vinyl)2 these new peaks are not lost on re-
dissolution. Instead, two peaks of approximately equal inten-
sity are recorded at 22.9 and 26.9 ppm in the solution
Reaction of PdX2(PPh2vinyl)2 (X = Cl, I) and Et2O·BF3
The addition of Et2O·BF3 to a CH2Cl2 solution of
PdCl2(PPh2vinyl)2 results in an immediate yellow to orange
© 2000 NRC Canada

1078
Can. J. Chem. Vol. 78, 2000
Fig. 5. Single crystal X-ray diffraction structure of [Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2.
color change. Removal of solvent in vacuo after 12 h and
recrystallization from Et2O–CH2Cl2 yields the crystallo-
graphically characterized [Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2, formed
by a combination of halide abstraction and exchange
(Fig. 5). Solution NMR spectroscopy indicates that this air
stable complex is the sole palladium containing product. The
complex is stable in CH2Cl2, but appears to be reduced to
palladium metal in CHCl3. Whilst reports exist of BF3 ex-
traction in palladium phosphine systems (16), it is notable
that the reaction of PdCl2(PPh2vinyl)2 with AgBF4 results in
palladium reduction to the phosphallyl complex [Pd(η1-
PPh2vinyl)(η3-PPh2vinyl)]2[BF4]2 (17) (Scheme 1).
The reactivity of PdI2(PPh2vinyl)2 with Et2O·BF3 differs
markedly from that of the chloride analogue. Under identical
conditions halide abstraction does not occur. The majority of
the complex is recovered unchanged, with the remaining ma-
terial undergoing phosphine abstraction to sym-[PdI2(PPh2vi-
nyl)]2. Abstraction occurs by virtue of the Lewis acid–base
interaction with BF3; a reaction that is confirmed by the ob-
servation of a comparable 31P{1H} NMR resonance from bi-
nary phosphine–BF3 mixtures. The latter adduct is air
sensitive, being hydrolyzed and oxidized in air to Ph2P(O)vi-
nyl. Separation and characterization of PdI2(PPh2vinyl)2,
Ph2P(O)vinyl, and sym-[PdI2(PPh2vinyl)]2 are thus accom-
plished by similar methods to those employed in UV initi-
ated reaction studies.
The respective centrosymmetric and distorted square pla-
nar structures that have been crystallographically observed
for trans-PdCl2(PPh2vinyl)2 and trans-PdI2(PPh2vinyl)2 have
been confirmed using CP/MAS NMR spectroscopy. The lat-
ter technique, in conjunction with solution NMR spectros-
copy, indicates that UV irradiation of PdCl2(PPh2vinyl)2
affords cis and trans- PdCl2(PPh2vinyl)2. Similar treatment
of PdI2(PPh2vinyl)2 results in phosphine dissociation and the
formation of sym-[PdI2(PPh2vinyl)]2. PdCl2(PPh2vinyl)2
reacts in the presence of the Lewis acid Et2O·BF3 to yield
[Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2, whilst the corresponding io-
dide again undergoes phosphine dissociation forming sym-
[PdI2(PPh2vinyl)]2. Although UV irradiation and Lewis
acids have been reported to initiate vinyl phosphine poly-
merization, no evidence suggesting such reactivity is recorded
in the present study.
Experimental
Crystallographic characterization
Data collection and structure solution for trans-
PdCl2(PPh2vinyl)2, trans-PdI2(PPh2vinyl)2, and [Pd(µ-
Cl)(PPh2vinyl)2]2[BF4]2 were performed using published
methods (18), Table 4.4
4 Complete X-ray data have been deposited as supplementary material and may be purchased from the Depository of Unpublished Data, Doc-
ument Delivery, CISTI, National Research Council Canada, Ottawa, ON K1A 0S2. Crystallographic data for the structures reported in this
paper have been deposited with the Cambridge Crystallographic Data Centre (CCDC Nos. 134114, 134115, and 136137, respectively).
Copies of the data can be obtained, free of charge, on application to the Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, U.K. (Fax:
44-1223-336033 or e-mail: deposit@ccdc.cam.ac.uk).
© 2000 NRC Canada

Hursthouse et al.
1079
Table 4. Crystal data for trans-PdCl2(PPh2vinyl)2, trans-PdI2(PPh2vinyl)2, and [Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2.
trans- PdCl2-(PPh2vinyl)2
trans- PdI2-(PPh2vinyl)2
[Pd(µ-Cl)(PPh2-vinyl)2]2[BF4]2
Color and habit
Size (mm)
Empirical formula
Formula weight
a (Å)
b (Å)
c (Å)
α (°)
β (°)
γ (°)
V (Å3)
Mo-Kα, λ (nm)
System
Space group
Z
yellow block
0.30 × 0.20 × 0.20
C14H13ClPPd
300.86
8.0956(2)
9.3183(4)
10.2254(4)
67.3560(14)
88.185(2)
68.614(2)
657.57(4)
red block
yellow block
0.10 × 0.10 × 0.05
C29H28BCl3F4P2Pd
738.01
13.3531(3)
13.5800(5)
17.4792(5)
—
103.4594(17)
—
3082.54(16)
0.71073
0.30 × 0.20 × 0.20
C28H26I2P2Pd
784.63
9.6628(3)
11.8875(5)
14.1588(5)
68.7735(17)
77.089(2)
68.184(2)
1400.02(9)
0.71073
triclinic
P1
2
0.71073
triclinic
P1
2
monoclinic
P21/n
4
Temperature (K)
Collection
Total reflections
Observed data (I > 2σ(I))
2θ
Absorption correction
Solution
Refinement
Hydrogen atoms
R
293(2)
Enraf Nonius KappaCCD
8104
2313
2.94 < 2θ < 25.03
SORTAV
SHELXS-97
SHELXL-97 Full matrix F2
Detected & riding
0.0226
293(2)
Enraf Nonius KappaCCD
19234
150(2)
Enraf Nonius KappaCCD
18038
4415
2.95 < 2θ < 23.25
SORTAV
SHELXS-97
SHELXL-97 Full matrix F2
Riding
5713
2.28 < 2θ < 26.38
SORTAV
SHELXS-97
SHELXL-97 Full matrix F2
Riding
0.0409
0.0359
wR
0.0598
0.233, –0.556
0.1014
0.878, –1.018
0.0830
1.246, –0.850
Difference (eÅ–3)
1
3.3. H and 31P{1H} NMR spectra were recorded and corre-
Synthesis and spectroscopy
spond to published data (9).
Solvents were dried and distilled under nitrogen by con-
ventional methods (19). Palladium chloride, diphenylvinyl-
phosphine, and Oxone® (potassium peroxymonosulfate,
2KHSO5·KHSO4·K2SO4) were obtained from Aldrich and
used as received. Pd(PhCN)2Cl2 was prepared by published
methods (20). Solution NMR were recorded in CDCl3 at
UV irradiation
The following is typical of the treatment of chloro- and
iodo- complexes. PdCl2(PPh2vinyl)2 (0.70 g; 1.16 mmol)
was dissolved in 10 cm3 of dry CH2Cl2. The solution was
placed in a ca. 5 cm diameter petri dish, and exposed to UV
radiation (λ ≥ 200 nm, 200 W) for 2 min. Remaining solvent
was decanted from the precipitated material and the solid
dried in vacuo. Yield 0.65 g (93% wt/wt).
1
270.1, 67.9, 81.0 MHz for H, 13C{1H}, and 31P{1H}, re-
spectively, using a JEOL GSX-270 spectrometer. CP/MAS
31P{1H} NMR was recorded using a 7mm bore Varian
UNITYplus spectrometer at 121 MHz. Acquisition parame-
ters were; spectral width 100 kHz, relaxation delay 20.0 s,
spin-rate 4500 Hz.
BF3 reactivity
PdCl2(PPh2vinyl)2: The complex was prepared on a 5 g
scale using published methods; typical yields of 79–88% be-
ing obtained. Elemental analysis for C28H26Cl2P2Pd, ex-
The following is typical of the treatment of chloro- and
iodo- complexes. PdCl2(PPh2vinyl)2 (0.087 g; 0.14 mmol)
was dissolved in 10cm3 of dry CH2Cl2 under nitrogen. The
addition of 100 µL Et2O·BF3 (0.79 mmol) produced no vi-
sual change. The solution was stirred for ca. 12 h and con-
centrated to dryness before further study. Yield 0.67 g (96%
wt/wt).
1
pected: C 55.9, H 4.4; found: C 56.1, H 4.4. H and 31P{1H}
NMR spectra were recorded and found to correspond to pub-
lished data (9).
PdI2(PPh2vinyl)2: The complex was prepared by halide
metathesis of PdCl2(PPh2vinyl)2. Thus, PdCl2(PPh2vinyl)2
(4.05 g; 6.8 mmol) was dissolved in CH2Cl2 (25 cm3) and
stirred with 10 cm3 aqueous saturated NaI. After 0.5 h the
aqueous solution was separated. The process was repeated
with two further portions of aq. NaI. Finally the organic
layer was separated and PdI2(PPh2vinyl)2 precipitated by the
addition of Et2O. Yield (4.85 g, 91%). Elemental analysis
for C28H26I2P2Pd, expected: C 42.8, H 3.3; found: C 42.8, H
Ph2P(O)vinyl: PPh2vinyl (1.08 g; 5.1 mmol) was dissolved
in CH2Cl2 (25 cm3) and slurried with Oxone® for 1 d, after
which the solution was filtered and concentrated to dryness
affording Ph2P(O)vinyl in quantitative yield. Elemental anal-
ysis for C14H13OP, expected: C 64.5, H 5.7; found: C 64.7,
H 6.0. NMR (see Table 3). IR (KBr); ν(O=P) 1148 cm–1;
MS (EI) m/e = 228 (100%).
© 2000 NRC Canada

1080
Can. J. Chem. Vol. 78, 2000
2. D.M. Paisley and C.S. Marvel. J. Polym. Sci. 56, 533 (1962).
3. A.W. Verstuyft, L.W. Cary, and J.H. Nelson. Inorg. Chem. 15,
3161 (1976).
4. A.W. Verstuyft, D.A. Redfield, L.W. Cary, and J.H. Nelson.
Inorg. Chem. 15, 1128 (1976); J.A. Rahn, M.S. Holt, and J.H.
Nelson. Polyhedron, 8, 897 (1989).
5. Palladium reagents and catalysts innovations in organic syn-
thesis. T. Jiro, John Wiley and Sons, Chichester, 1995.
6. S.O. Grim and R.L. Keiter. Inorg. Chim. Acta, 4, 56 (1970).
7. S.J. Coles, P. Faulds, M.B. Hursthouse, D.G. Kelly, G.C.
Ranger, and N.M. Walker. J. Chem. Res. 418 (S) 1811 (M)
(1999).
8. S.J. Coles, P. Faulds, M.B. Hursthouse, D.G. Kelly, G.C.
Ranger, A.J. Toner, and N.M. Walker. J. Organomet. Chem.
586, 234 (1999).
[PdI2(PPh2vinyl)]2: Complex was formed in ca. 5% yield
along with Ph2P(O)vinyl by the irradiation of PdI2(PPh2vi-
nyl)2. A ca. 12% yield, along with F3B·PPh2vinyl, was ob-
served from the reaction of PdI2(PPh2vinyl)2 and Et2O·BF3.
In the latter reaction F3B·PPh2vinyl was identified by com-
parison with 31P{1H} NMR data obtained from binary
Et2O·BF3 and PPh2vinyl solutions (δ = 1.7 ppm, CDCl3), and
undergoes hydrolysis and oxidation in air to Ph2P(O)vinyl.
sym-[PdI2(PPh2vinyl)]2 was readily separated from
Ph2P(O)vinyl by hexane extraction of the latter. The com-
plex was then recrystallized from CH2Cl2–Et2O from which
this comparatively insoluble complex preferentially precipi-
tates. Manual separation from traces of the visually distinct
PdI2(PPh2vinyl)2 affords spectroscopically and analytically
pure sym-[PdI2(PPh2vinyl)]2·Et2O. Elemental analysis for
C28H26I4P2Pd2·Et2O, expected: C 31.5, H 3.0; found: C 31.4,
9. J.A. Rahn, M.S. Holt, M. O’Neil-Johnson, and J.H. Nelson.
Inorg. Chem. 27, 1316 (1988).
10. J.A. Rahn, D.J. O’Donnell, A. R. Palmer, and J.H. Nelson.
Inorg. Chem. 28, 2631 (1989).
1
H 2.7. H (for proton notation see Table 3) δ = 5.58 (Hb dd
3
3J(PH) = 20.7 Hz, J(HaHc) = 18.2 Hz, 2H, Hc), 6.10 (Hc dd
3
3J(PH) = 42.4 Hz, J(HaHb) = 12.0 Hz, 2H, Hb), 7.10 (Ha
11. N. Alcock, T.J. Kemp, F.L. Wimmer, and O. Traverso. Inorg.
Chim. Acta, 44, L245 (1980); N. Alcock, T.J. Kemp, and F.L.
Wimmer. J. Chem. Soc. Dalton Trans. 635 (1981).
12. N.A. Bailey and R.A. Mason. J. Chem. Soc. A, 2594 (1968).
13. H. Kin-Chee, G.M. McLaughlin, M. McPartlin, and G.B. Rob-
ertson. Acta Crystallogr. Sect. B: Struct. Crystallogr. Cryst.
Chem. B38, 421 (1982).
14. M. Cusumano, G. Guglielmo, V. Ricevuto, S. Sostero, O.
Traverso, and T.J. Kemp. J. Chem. Soc. Chem. Commun. 775
(1979); M. Cusumano, G. Guglielmo, V. Ricevuto, S. Sostero,
O. Traverso, and T.J. Kemp. J. Chem. Soc. Dalton Trans. 302
(1981).
15. N.W. Alcock, W.L. Wilson, and J.H. Nelson. Inorg. Chem. 32,
3193 (1993).
16. H.C. Clark and K.R. Dixon. J. Am. Chem. Soc. 91, 596
(1969).
17. W.L. Wilson, J.H. Nelson, and N.W. Alcock. Organometallics,
9, 1699 (1990).
18. R.H. Blessing. J. Appl. Crystallogr. 30, 421 (1997); G.M.
Sheldrick. Acta. Crystallogr. Sect. A: Fundam. Crystallogr.
A46, 467 (1990); G.M. Sheldrick. SHELX97. University of
Göttingen, Germany.
ddd 2J(PH) = 24.1 Hz, 3J(HaHc) = 18.2 Hz, 3J(HaHb) =
12.0 Hz, 2H, Ha), 7.36–7.75 (m, 20H, Ph). 31P{1H} δ = 26.9.
[Pd(µ-Cl)(PPh2vinyl)2]2[BF4]2: Product formed by the method
outlined above was crystallized from dichloromethane–
diethylether to afford an orange microcrystalline solid. There
is evidence of decomposition in air and over several hours in
chloroform to afford palladium metal. However, the complex
is sufficiently stable in CDCl3 to obtain NMR spectra. Ele-
mental analysis for C28H26BClF4PPd·CH2Cl2, expected: C
1
47.1, H 3.8; found: C 47.3, H 3.6. H (for proton notation
see Table 3) δ = 5.70 (Hb t, br), 6.06 (Hc t, br), 6.22 (Ha m,
br), 7.38–7.58 (m, 20H, Ph). 31P{1H}–31P{1H} δ = 28.6.
Acknowledgements
CP/MAS NMR spectra were recorded by the EPSRC
Solid State NMR Service, Durham U.K. Mr P. Warren
(MMU) is thanked for obtaining solution NMR data. A.J.T.
acknowledges funding from an MMU Faculty Studentship.
19. S.J. Coles, M.B. Hursthouse, D.G. Kelly, A.J. Toner, and N.M.
Walker. J. Organomet. Chem. 580, 304 (1999).
20. G.K. Anderson and M. Lin. Inorg. Synth. 28, 61 (1990).
References
1. C. Wu and F.J. Welch. J. Org. Chem. 30, 1229 (1965).
© 2000 NRC Canada