Synthesis and polymerization performance of PdII complexes of new 2-hydroxyethyl-substituted diphosphane ligands

Article abstract of DOI:10.1002/ejic.200300903

We have synthesized a new diphosphane ligand, 1,3-bis[(2-hydroxyethyl) (phenyl)phosphanyl]propane (2*) (*: mixture of meso- and racemic diastereoisomers), and its corresponding neutral dichloro palladium(II) (3*), diiodo palladium(II) (4*), and dicationic diacetonitrile palladium(II) ditetrafluoroborate (5*) complexes. Separation of the 4 rac and 4 meso diastereoisomers was achieved by column chromatography and subsequent crystallization. Assignments of the particular complex geometries of 3 meso and 4 rac were facilitated by single-crystal X-ray diffraction analysis. After activation with MAO, complex 3* exhibits superior activity in the homopolymerization of 2-norbornene relative to that of the dichloro Pd ^II derivative of 1,3-bis(diphenylphosphanyl)propane (dppp). Compound 5* and the dppp-analogue possess similar catalytic potentials in ethylene/CO copolymerization experiments. Applying complex 5* to propylene/CO copolymerization leads to highly regio- and predominantly stereo-regular polyketone materials. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Full text of DOI:10.1002/ejic.200300903

FULL PAPER
Synthesis and Polymerization Performance of PdII Complexes of
New 2-Hydroxyethyl-Substituted Diphosphane Ligands
Uwe W. Meier,[a] Ulf Thewalt,[b] Tony Debaerdemaeker,[b] and Bernhard Rieger*[a]
Keywords: Homogeneous catalysis / Palladium / Phosphane ligand / Polyketone / Polymerization
We have synthesized a new diphosphane ligand, 1,3-bis[(2-
MAO, complex 3* exhibits superior activity in the homopoly-
hydroxyethyl)(phenyl)phosphanyl]propane (2*) (*: mixture of
merization of 2-norbornene relative to that of the dichloro
meso- and racemic diastereoisomers), and its corresponding PdII derivative of 1,3-bis(diphenylphosphanyl)propane
neutral dichloro palladium(II) (3*), diiodo palladium(II) (4*),
(dppp). Compound 5* and the dppp-analogue possess similar
and dicationic diacetonitrile palladium(II) ditetrafluoroborate
catalytic potentials in ethylene/CO copolymerization experi-
(5*) complexes. Separation of the 4 rac and 4 meso diastereo- ments. Applying complex 5* to propylene/CO copolymeri-
isomers was achieved by column chromatography and sub- zation leads to highly regio- and predominantly stereo-
sequent crystallization. Assignments of the particular com- regular polyketone materials.
plex geometries of 3 meso and 4 rac were facilitated by
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
single-crystal X-ray diffraction analysis. After activation with
Germany, 2004)
Introduction
Bridged bisphosphane ligands play an important role in
homogeneous catalysis. The variety of tools available for
tailoring their structures makes these ligands ideal plat-
forms upon which to design selective, molecularly defined
catalysts for small-molecule transformations and for poly-
merization reactions.[1] Until now, the functionalities that
have been attached, such as oxygen-containing or fluori-
nated substituents, have been used primarily to impart par-
ticular steric and electronic properties to the ligands, as well
as solubility properties of the complexes.[2] A novel ap-
proach for further developments is the introduction of suit-
able functional groups that help to open up selective reac-
tion channels by reversible interactions with either the me-
tal center, the incoming substrate, or the growing polymer
chain. In this paper we report the synthesis and structural
characterization of PdII complexes of a new bisphosphane
ligand, which bears (2-hydroxyethyl)(phenyl)phosphane
units (Scheme 1). We have performed 2-norbornene homo-
polymerizations, as well as ethylene/CO and propylene/CO
copolymerization experiments, to investigate the catalytic
potential of these novel complex structures.
Scheme 1. Novel hydroxy-functionalized bisphosphane PdII com-
plexes
Results and Discussion
Ligand and Complex Synthesis
Nucleophilic attack of the dilithium diphosphide, which
is accessible from 1,3-bis(phenylphosphanyl)propane (1) by
deprotonation with 2 equiv. of nBuLi, on ethylene oxide[3]
gave, after aqueous workup, the desired bisphosphane 2*
(Scheme 2). We obtained the ligand as a mixture of the ra-
cemic (R,R;S,S) and meso (R,S) components in a 1:1.3 ratio
(31P NMR: δrac ϭ Ϫ32.50, δmeso ϭ Ϫ32.64 ppm).
Complexation of 2* with (COD)PdCl2 in CH2Cl2 gave
the corresponding neutral dichloro palladium() complex
(3*) in the expected ratio of diastereoisomers (1:1.3,
Scheme 3). Extraction of the mixture 3* with DMSO and
subsequent crystallization from DMSO/CH2Cl2 gave pure
3 meso. Replacement of the chloro ligands in 3* by treat-
[a]
Department of Inorganic Chemistry II, Materials and Catalysis,
University of Ulm,
Albert-Einstein-Allee 11, 89069 Ulm, Germany
Fax: (internat.) ϩ 49-(0)731-502-3039
E-mail: bernhard.rieger@chemie.uni-ulm.de
Sektion Röntgen- und Elektronenbeugung, University of Ulm,
Albert-Einstein-Allee 11, 89069 Ulm, Germany
[b]
Eur. J. Inorg. Chem. 2004, 3057Ϫ3062
DOI: 10.1002/ejic.200300903
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3057

U. W. Meier, U. Thewalt, T. Debaerdemaeker, B. Rieger
FULL PAPER
Scheme 2. Synthesis of 2-hydroxyethyl-substituted bisphosphane 2*
ment with sodium iodide in DMSO affords the correspond-
ing diiodo palladium() compounds 4*. Separation into
pure racemic (4 rac) and meso fractions (4 meso) was per-
formed by crystallization and subsequent chromatography
over silica (CH2Cl2/acetone).[4] The dicationic complex 5*
was obtained from 3* by halide abstraction using AgBF4
in acetonitrile.
Single crystals of 3 meso (Figure 1, left) were grown from 2.358(2) A] and [1,2-bis(diphenylphosphanyl)ethane]PdI2
a DMSO extract of 3* after treatment with CH2Cl2. Suit- (PdϪP: 2.2608(14)/2.2756(12) A; PdϪI: 2.6649(8)/
able crystals of 4 rac (Figure 1, right) were obtained by slow 2.6446(10) A] analogues.
Scheme 3. Preparation of the neutral and dicationic PdII complexes
of ligand 2*
˚
˚
[5,6]
˚
The corresponding bond
evaporation of the solvent from a CH2Cl2/acetone (1:1) angles at the Pd centers of the complexes 3 meso and 4 rac
solution. The coordination geometry around the PdII center are similar, i.e., they are independent of the nature of the
is nearly square planar, as expected for palladium com- chloro or iodo ligands, but the bond angle XϪPdϪX is
plexes of non-rigid diphosphanes. Both complexes show slightly enlarged in case of X ϭ Cl [91.24(5)°] relative to
PdϪP and PdϪHal bond lengths (Table 1) that resemble X ϭ I [90.46(2)°]. The orientation of the hydroxyethyl sub-
those of the symmetric [1,3-bis(diphenylphosphanyl)pro- stituents is fixed in the solid state by intermolecular hydro-
˚
pane]PdCl2 (PdϪP: 2.244(1)/2.249(2) A; PdϪCl: 2.351(1)/ gen bonding between neighboring complexes. Pairs of two
Figure 1. ORTEP plots of 3 meso (left) and 4 rac (right) complexes and arrangements of the complexes in the solid state; thermal
ellipsoids are depicted at the 50% probability level; hydrogen atoms are omitted
3058
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Eur. J. Inorg. Chem. 2004, 3057Ϫ3062

PdII Complexes of New 2-Hydroxyethyl-Substituted Diphosphane Ligands
FULL PAPER
˚
Table 1. Selected bond lengths (A) and angles (deg) for 3 meso and
4 rac
Table 2. Results of 2-norbornene and ethylene homopolymerization
experiments using 3* and the reference dpppPdIICl2 after activation
with MAO in toluene
3 meso
4 rac
Run[a] Monomer
Catalyst
Al:Pd[b] Yield[c] Activity[d]
Bond lengths
Pd(1)ϪP(1)
Pd(1)ϪP(2)
Pd(1)ϪCl(1)
Pd(1)ϪCl(2)
P(1)ϪC(1)
P(1)ϪC(6)
P(1)ϪC(8)
P(2)ϪC(3)
P(2)ϪC(4)
P(2)ϪC(14)
Bond angles
P(1)ϪPd(1)ϪP(2)
Cl(1)ϪPd(1)ϪCl(2)
P(1)ϪPd(1)ϪCl(1)
P(1)ϪPd(1)ϪCl(2)
P(2)ϪPd(1)ϪCl(2)
P(2)ϪPd(1)ϪCl(1)
2.243(1)
2.254(1)
2.354(1)
2.381(1)
1.815(5)
1.827(5)
1.805(5)
1.825(5)
1.832(5)
1.817(5)
PdϪP(1)
PdϪP(2)
PdϪI(1)
PdϪI(2)
P(1)ϪC(1)
P(1)ϪC(4)
P(1)ϪC(8)
P(2)ϪC(3)
P(2)ϪC(6)
P(2)ϪC(14)
2.268(2)
2.264(2)
2.661(1)
2.657(1)
1.827(6)
1.801(6)
1.792(6)
1.816(6)
1.822(6)
1.813(6)
1
2
3
4
norbornene 3*
500
500
1000
0.5
0.2
0.8
0.3
180
80
320
130
norbornene (dppp)PdCl2
norbornene 3*
norbornene (dppp)PdCl2 1000
[a] Toluene (100 mL), catalyst (15 µmol), 2-norbornene (5 g), 25 °C,
10 min. Ratio Al(MAO):Pd. [g]. [kg[mol(Pd)h]Ϫ1].
[b]
[c]
[d]
poly(norbornene) material[9] (Table 2). The monomer con-
version is more than twice as high as that obtained when
using the structurally related dichloro(dppp)palladium()
complex, under analogous experimental conditions.
94.54(4)
91.24(5)
87.25(5)
178.41(5)
86.94(4)
175.61(5)
P(1)ϪPdϪP(2)
I(1)ϪPdϪI(2)
P(1)ϪPdϪI(1)
P(1)ϪPdϪI(2)
P(2)ϪPdϪI(2)
P(2)ϪPdϪI(1)
94.89(6)
90.46(2)
87.07(4)
177.47(4)
87.55(4)
177.08(4)
The dicationic complex 5* shows a satisfying activity in
the alternating copolymerization of ethylene and carbon
monoxide after activation with methanol; it is similar to the
results obtained when using the standard polyketone cata-
lyst [(dppp)Pd(NCCH3)2](BF4)2 (Table 3). In the propylene/
CO copolymerization reaction, complex 5* shows a com-
pletely different behavior than that of the dppp-ligated cata-
lyst, which is known to produce regio-irregular polyke-
tones.[10] In contrast, the propylene/CO material resulting
from 5* is brittle and insoluble in common solvents, which
we attribute to a polyspiroketal chain structure. 13C NMR
spectroscopy investigations in [D2]hexafluoro-2-propanol
(HFIP) proved that the product has high regioregularity
(headϪtail sequences Ͼ97%; Figure 2). Interestingly, the
methyl area is dominated by a single resonance,[11] which
indicates a stereoregular, isotactic microstructure. This find-
complex molecules are bridged by two hydrogen bonds in
the unit cell of 3 meso. The intermolecular oxygenϪoxygen
distance is 2.754 A. In 4 rac, one molecule is bridged by
hydrogen bonding with two other complex units, which,
thus, forms a linear polymeric chain. The intermolecular
oxygenϪoxygen distance in 4 rac (2.853 A) is slightly en-
larged relative to that in 3 meso.
˚
˚
Homo- and Copolymerization Experiments
The use of bulky, substituted chelating ligands is a pre- ing is supported by the relatively high melting transition
requisite for achieving polymeric products in late transition temperature (Tm ϭ 169 °C).[12]
metal catalyzed ethylene polymerization reactions.[7] There-
One reason for the observed regioregular microstructure
fore, we chose 2-norbornene to be the first monomer we could be the alkyl substitution on the phosphorus moieties,
applied to verify the homopolymerization capabilities of which is known to produce regioregular polyketones.[13] We
these new complexes. In addition, chain termination in- have no genuine explanation for the high stereoregularity
duced by β-hydride elimination is thermodynamically unfa- of the propylene/CO copolymer material (PCO). The chiral
vorable when using this monomer.[8] The active complex cage, formed by the phenyl- and 2-hydroxyethyl P-substitu-
species was obtained by treating the dichloropalladium() ents around the PdII center is not significantly pronounced
compound 3* with MAO in toluene. As expected, polymer- to explain the isotacticity of the PCO product. One possible
ization of 2-norbornene resulted in a completely insoluble explanation is that the C2-symmetric rac-catalyst species
Table 3. Ethylene/CO and propylene/CO copolymerization performance of 5* in comparison to the related dpppPdII complex
Amount[a]
Yield[b]
Activity[c]
Mw
Mw/Mn
Regio[e]
[d]
Run
Monomer
Catalyst
5[f]
6[f]
E/CO
E/CO
5*
20
20
1.3
1.2
21
20
Ϫ[g]
Ϫ[g]
Ϫ[g]
Ϫ[g]
Ϫ
Ϫ
dppp[h]
7[i]
8[i]
P/CO
P/CO
5*
40
20
0.15
1.3
0.2
3.4
Ϫ[i]
65
Ϫ[i]
1.8
97
56
dppp[h]
[a]
[c]
[d]
[e]
[µmol]. [b] [g]. [kg[mol(Pd)h]Ϫ1]. [kg molϪ1]. Determined by GPC in CHCl3. Regioregularity (headϪtail units) [%]. Determined
by 13C NMR spectroscopy in [D2]HFIP and CDCl3. 100-mL Steel autoclave, CH2Cl2 (40 mL), MeOH (1 mL), ethylene (40 bar), CO
[f]
(80 bar), 25 °C, 3 h. Not determined.[h] (NCCH3)2(dppp)Pd(BF4)2. 100-mL Steel autoclave, CH2Cl2 (40 mL), MeOH (run 7: 1 mL;
[g]
[i]
run 8: 0.12 mL), propylene (saturated for 30 min), CO (60 bar), 25 °C, 19 h.
Eur. J. Inorg. Chem. 2004, 3057Ϫ3062
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3059

U. W. Meier, U. Thewalt, T. Debaerdemaeker, B. Rieger
FULL PAPER
Strem Chemicals), ethylene oxide (Fluka), AgBF4 and (dppp)PdCl2
(Aldrich), and 2-norbornene (Merck) were used as received.
[14]
[15]
(COD)PdCl2
and (CH3CN)2(dppp)Pd(BF4)2
were prepared
according to literature procedures. 1H, 13C, 19F, and 31P NMR
spectra were recorded on either a Bruker DRX 400 or an AMX
500 spectrometer. TMS was used as internal standard for the 1H
and 13C spectra. 31P NMR spectroscopic shifts were referenced to
the external standard H3PO4 (85%). 19F NMR spectra were cali-
brated to CCl3F as the internal standard. Mass spectra were ac-
quired using Varian MAT 711 and Finnigan TSQ 7000 instru-
ments. X-Ray structural analyses were performed as described.
MAO (in toluene) was supplied by WITCO. Ethylene (2.7), propyl-
ene (2.6), and carbon monoxide (2.0) were used without further
purification as received from BASF.
1,3-Bis[(2-hydroxyethyl)(phenyl)phosphanyl]propane (2*): 1,3-Bis-
(phenylphosphanyl)propane (1) (11.3 g, 43.4 mmol) was dissolved
in THF (400 mL) and cooled to Ϫ78 °C. Subsequently, 1.6  n-
butyllithium in hexane (53.4 mL, 86.8 mmol) was added to the mix-
ture, which was warmed to room temperature overnight. The or-
ange solution was then cooled to Ϫ18 °C and ethylene oxide
(7.63 g, 174 mmol, 2 equiv.) was condensed into the reaction mix-
ture. After stirring the resulting white suspension for 1 h at room
temperature, all the solvents are removed in vacuo. The residue was
hydrolyzed with water and deoxygenated 1  hydrochloric acid was
added, to pH 1, to protonate the bisphosphane. The aqueous solu-
tion was extracted with CH2Cl2 to remove impurities. Sub-
sequently, after adding CH2Cl2 (100 mL) to the resulting acidic
water phase, the mixture was adjusted to pH 7, to deprotonate
the bisphosphane, by adding deoxygenated aqueous NaOH. The
mixture was extracted with CH2Cl2 and the combined organic lay-
ers were dried over Na2SO4. Evaporation of the solvent in vacuo
gave ligand 2* as a colorless, highly viscous oil. Yield 12.2 g (82%).
1H NMR (CDCl3): δ ϭ 7.47Ϫ7.39 (m, 4 H, Ph), 7.33Ϫ7.25 (m, 6
H, Ph), 3.68Ϫ3.59 (m, 4 H, CH2O), 2.30Ϫ2.15 (br. s, 2 H, OH),
2.01Ϫ1.88 (m, 4 H, PCH2), 1.87Ϫ1.72 (m, 4 H, PCH2, bridge),
1.52Ϫ1.39 (m, 2 H, CH2, bridge) ppm. 13C NMR (CDCl3): δ ϭ
Figure 2. 13C NMR spectrum ([D2]HFIP) of a propylene/CO-co-
polymer resulting from the use of 5* in methanol
has a higher activity than the meso complex and leads to
the observed isotacticity through interaction of the 2-
hydroxy ethyl substituents with the PdII dicationic metal
center (O-coordination). This situation would afford the re-
versible formation of a chiral and stereorigid metallacycle
that might lead to an effective enantiofacial differentiation
of the incoming propylene monomer. A second explanation
involves reversible interactions of the same OH groups with
the coordinated acyl species after CO insertion. Further
work toward gaining a deeper insight into these mecha-
nisms is underway.
Conclusion
Our research on multifunctional chelating ligands re-
sulted in the preparation of a 2-hydroxyethyl-substituted bi- 137.7Ϫ137.4 (2 ϫ d, rac/meso, ipso Ph), 132.4Ϫ132.1 (2 ϫ d, rac/
meso, ortho Ph), 128.9 (s, para Ph), 128.5Ϫ128.3 (2 ϫ d, rac/meso,
meta Ph), 60.0 (d, CH2-OH), 32.0 (vt, rac/meso, PCH2), 29.5 (vt,
PCH2, bridge), 22.4Ϫ22.1 (m, CH2, bridge) ppm. 31P{1H} NMR
(CDCl3): δ ϭ Ϫ32.50 (s, rac), Ϫ32.64 (s, meso) ppm; ratio rac:
meso ϭ 1:1.3. IR (film): ν˜ ϭ 3344 cmϪ1 (br., OH). MS (FD): m/z
(%) ϭ 348 (100) [M]ϩ, 303 (5) [M Ϫ CH2CH2OH]ϩ. C19H26O2P2
(348.4): calcd. C 65.51, H 7.52; found C 65.23, H 7.35.
sphosphane 2* that is accessible by nucleophilic attack of
the corresponding dilithium bisphosphide on ethylene ox-
ide. The new ligand exists as a mixture of racemic and meso
diastereoisomers in a 1:1.3 ratio. Separation of the dia-
stereoisomeric compounds was performed by crystallization
and column chromatography of the diiodo PdII complexes
4*. The neutral dichloro 3* and the dicationic diacetonitrile
PdII ditetrafluoroborate complexes 5* are active for the
Dichloro{1,3-Bis[(2-hydroxyethyl)(phenyl)phosphanyl]propane}-
homopolymerization of norbornene and CO/olefins, respec- palladium(II) (3*): Ligand 2* (9.42 g, 27.1 mmol) was dissolved in
CH2Cl2 (50 mL) and then added to a solution of (COD)PdCl2
(7.72 g, 27.1 mmol) in CH2Cl2 (450 mL). After stirring the mixture
for 1 h, the precipitated product was separated. Washing with
CH2Cl2 and pentane and then drying in vacuo gave complex 3* as
a yellow solid. Yield:13.5 g (95%). Extraction of compound 3* with
a small amount of DMSO, followed by crystallization from the
DMSO extract by the addition of CH2Cl2, gave the pure meso com-
plex (3 meso) containing single-crystals suitable for X-ray diffrac-
tively. Interestingly, the application of complex 5* affords
isotactic propylene/CO copolymers. Elucidating the differ-
ent polymerization behavior of the rac and meso isomers
and studying the influence of the 2-hydroxyethyl P-substitu-
ents will be the subjects of further investigations.
1
Experimental Section
tion analysis. H NMR ([D6]DMSO): δ ϭ 8.00Ϫ7.91 [m, 4H (rac)
ϩ4H (meso), Ph], 7.55Ϫ7.39 [m, 6H (rac) ϩ 6H (meso), Ph], 5.10
(t, 2 H, rac, OH), 5.05 (t, 2 H, meso, OH), 4.08Ϫ3.85 [m, 4H (rac)
ϩ 4H (meso), CH2O], 2.91Ϫ2.78 (m, 2 H, rac), 2.77Ϫ2.64 (m, 2 H,
General: Reactions were performed under argon using standard
Schlenk techniques. Solvents were dried by distillation from CaH2
(dichloromethane) and LiAlH4 (diethyl ether, n-pentane). Dry meso), 2.64Ϫ2.40 [m, 2H (rac) ϩ 2H (meso)], 2.40Ϫ2.26 (m, 2 H,
acetonitrile was received from Roth, deoxygenated in vacuo, and
stored over molecular sieves (3 A). H2O was deoxygenated in vacuo
and saturated with argon. 1,3-Bis(phenylphosphanyl)propane (1;
meso), 2.22Ϫ2.07 [m, 2H (rac) ϩ 3H (meso)], 2.07Ϫ1.90 (m, 2 H,
rac), 1.88Ϫ1.70 (m, 2 H, rac), 1.20Ϫ0.96 (m, 1 H, meso) ppm.
31P{1H} NMR ([D6]DMSO): δ ϭ 17.0 (s, rac), 13.6 (s, meso) ppm;
˚
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PdII Complexes of New 2-Hydroxyethyl-Substituted Diphosphane Ligands
FULL PAPER
ratio rac:meso ϭ 1:1.3. IR (KI): ν˜ ϭ 3422 cmϪ1 (br., OH). MS
(FAB): m/z (%) ϭ 491 (76) [M Ϫ Cl]ϩ, 453 (100) [M Ϫ 2Cl]ϩ. diiodopalladium(II
{(PS,PЈR)-1,3-Bis[(2-hydroxyethyl)(phenyl)phosphanyl]propane}-
)
(4 meso): Yield 2.1 g (23%). 1H NMR
C19H26Cl2O2P2Pd (525.7): calcd. C 43.41, H 4.99; found C 43.30,
H 4.93.
([D6]DMSO): δ ϭ 7.98Ϫ7.91 (m, 4 H, Ph), 7.50Ϫ7.42 (m, 6 H,
Ph), 5.11 (t, br, 2 H, OH), 4.07Ϫ3.87 (m, 4 H, CH2O), 3.08Ϫ2.82
(m, 4 H, PCH2), 2.24Ϫ2.02 (m, 5 H, bridge), 1.22Ϫ1.00 (m, 1 H,
bridge) ppm. 31P{1H} NMR ([D6]DMSO): δ ϭ 5.48 (s) ppm. IR
(KI): ν˜ ϭ 3347 cmϪ1 (br., OH). MS (FAB): m/z (%) ϭ 581 (100)
[M Ϫ I]ϩ, 454 (7) [M Ϫ 2I]ϩ. C19H26I2O2P2Pd (708.6): calcd. C
32.21; H 3.70; found C 32.26; H 3.74.
{1,3-Bis[(2-hydroxyethyl)(phenyl)phosphanyl]propane}diiodo-
palladium(II) (4*) and Its Separation into 4 meso and 4 rac: The
following procedure was performed using solvents as supplied with-
out further purification. Complex 3* (7.0 g, 13.3 mmol) was dis-
solved in DMSO (200 mL). After adding NaI (7.97 g, 53.2 mmol),
the reaction mixture was stirred for 15 h at room temperature. The
DMSO was separated from the crude product by successive extrac-
tion with ether and removal of the resulting DMSO-containing
Diacetonitrile{1,3-bis[(2-hydroxyethyl)(phenyl)phosphanyl]propane}-
palladium(II) Ditetrafluoroborate (5*): AgBF4 (1.48 g, 7.62 mmol)
was added to a suspension of 3* (2.00 g, 3.81 mmol) in acetonitrile
ether layers. Extracting of the resulting solid with CH2Cl2 and ace- (80 mL). After stirring for 1 h, the reaction mixture was filtered
tone, followed by crystallization, led to an enrichment of the two
diastereoisomers in different product fractions. Complete separ-
ation and purification of the diastereoisomers was performed by
chromatography over silica (CH2Cl2/acetone, 1:2) and subsequent
crystallization.
and concentrated in vacuo. The concentrated solution was filtered
again and then the complex was precipitated with ether. The solid
was washed with diethyl ether and n-pentane and then dried in
vacuo to give 5*. Yield 2.4 g (89%). 1H NMR (CD3OD): δ ϭ
8.17Ϫ7.39 (m, 10 H, meso/rac, Ph), 4.26Ϫ3.92 (m, 2 H, meso/rac,
CH2), 3.78Ϫ3.61 (m,
2 H, meso/rac, CH2), 3.19Ϫ2.15 and
{(PS,PЈS)-1,3-Bis[(2-hydroxyethyl)(phenyl)phosphanyl]propane}-
1.64Ϫ1.45 (2 ϫ m, 10 H, meso/rac, CH2), 2.06 (CH3CN) ppm.
19F{1H} NMR (CD3OD): δ ϭ Ϫ155.55 (s) ppm. 31P{1H} NMR
(CD3OD): δ ϭ 44.30 (s, rac), 33.37 (s, meso) ppm; ratio rac:meso ϭ
1:1.3. IR (KI): ν˜ ϭ 3481 (br., OH), 2325, 2297 (w, CϵN), 1076
(br., BF4) cmϪ1. MS (FAB): m/z (%) ϭ 453 (100) [M Ϫ
2CH3CN,2BF4]ϩ.
diiodopalladium(II
)
and
{(PR,PЈR)-1,3-Bis[(2-hydroxyethyl)-
(phenyl)phosphanyl]propane}diiodopalladium(II) (4 rac): Yield: 2.8 g
(30%). 1H NMR ([D6]DMSO): δ ϭ 7.93Ϫ7.90 (m, 4 H, Ph),
7.51Ϫ7.42 (m, 6 H, Ph), 5.14 (t, br, 2 H, OH), 4.11Ϫ3.96 (m, 4 H,
CH2O), 3.14Ϫ2.84 (m, 4 H, PCH2), 2.24Ϫ2.11 (m, 2 H, bridge),
2.00Ϫ1.72 (m, 4 H, bridge) ppm. 31P{1H} NMR ([D6]DMSO): δ ϭ
7.27 (s) ppm. IR (KI): ν˜ ϭ 3425 cmϪ1 (br., OH). MS (FAB): m/z
2-Norbornene Polymerization Experiments: The corresponding di-
(%) ϭ 581 (100) [M Ϫ I]ϩ, 454 (10) [M Ϫ 2I]ϩ. C19H26I2O2P2Pd chloro PdII complex (15 µmol) was dissolved in toluene (final total
(708.6): calcd. C 32.21, H 3.70; found C 32.07, H 3.62.
volume including MAO: 100 mL), treated with MAO solution
Table 4. Summary of crystal data and structural refinement parameters for 3 meso and 4 rac
3 meso
4 rac
Empirical formula
Molecular mass
Crystal color and shape
Crystal size (mm)
Crystal system
C19H26Cl2O2P2Pd
525.64
colorless prism
0.15 ϫ 0.31 ϫ 0.46
monoclinic
I2/a
13.946(1)
11.120(1)
30.962(2)
C19H26I2O2P2Pd
708.54
orange needle fragment
0.26 ϫ 0.19 ϫ 0.12
orthorhombic
Pbcn
18.322(4)
18.947(3)
15.425(2)
Space group
˚
a (A)
˚
b (A)
˚
c (A)
α (°)
β (°)
γ (°)
90
101.23(1)
90
4709.5(5)
90
90
90
3
˚
V (A )
5354.7(17)
8
1.758
3.128
2704
Z
8
Calculated density [g/cm3]
Absorption coefficient [mmϪ1
F(000)
1.483
1.161
2128
]
θ range (°)
2.57Ϫ25.96
Ϫ16 ϭ h ϭ 16
Ϫ13 ϭ k ϭ 13
Ϫ38 ϭ l ϭ 32
13855
4538 [R(int) ϭ 0.0267]
1.093
R1 ϭ 0.0446
wR2 ϭ 0.1583
R1 ϭ 0.0497
wR2 ϭ 0.1650
3.340 and Ϫ1.232
2.76Ϫ26.00
Ϫ22 ϭ h ϭ 22
Ϫ23 ϭ k ϭ 23
Ϫ18 ϭ l ϭ 18
39740
5109 [R(int) ϭ 0.0825]
0.935
R1 ϭ 0.0311
wR2 ϭ 0.0660
R1 ϭ 0.0644
wR2 ϭ 0.0704
1.036 and Ϫ0.478
Index range
Reflections collected
Reflections unique
Goodness-of-fit on F2
Final Rint [I Ͼ 2σ(I)]
Rint (all data)
3
˚
Largest diff peak and hole (e/A )
Eur. J. Inorg. Chem. 2004, 3057Ϫ3062
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3061

U. W. Meier, U. Thewalt, T. Debaerdemaeker, B. Rieger
FULL PAPER
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[1b]
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used to locate the other hydrogen atoms.
CCDC-224744 (for 3 meso) and -224402 (for 4 rac) contain the
supplementary crystallographic data for this paper. These data can
be obtained free of charge at www.ccdc.cam.ac.uk/conts/retriev-
ing.html [or from the Cambridge Crystallographic Data Centre, 12
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Received December 5, 2003
[16]
[17]
Early View Article
Published Online May 25, 2004
3062
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Eur. J. Inorg. Chem. 2004, 3057Ϫ3062