1-Diisopropylaminophospholes: Synthesis and X-ray characterisations of new palladium and platinum complexes

Article abstract of DOI:10.1016/S0022-328X(01)01145-7

Starting from palladium precursor [Pd(CH₃CN)₂Cl₂], 1-diisopropylaminophospholes give dinuclear complexes, [Pd(phosphole)Cl₂]₂, which proved to be intermediates in the formation of mononuclear complexes, cis-[Pd(phosphole)₂Cl₂]. In contrast with the platinum precursor, only mononuclear complexes, [Pt(phosphole)₂Cl₂], are obtained with both cis and trans configurations. These new complexes were fully characterised by X-ray crystallography.

Full text of DOI:10.1016/S0022-328X(01)01145-7

Journal of Organometallic Chemistry 643–644 (2002) 19–26
www.elsevier.com/locate/jorganchem
1-Diisopropylaminophospholes: synthesis and X-ray
characterisations of new palladium and platinum complexes
Je´roˆme Hydrio a, Maryse Gouygou a,*, Fre´de´ric Dallemer b, Gilbert G.A. Balavoine a,
Jean-Claude Daran a,*
a Laboratoire de Chimie de Coordination du CNRS, 205, Route de Narbonne, 31077 Toulouse Cedex, France
b Rhodia Recherches, Centre de Recherche de Lyon, 85, A6enue des Freres Perret, BP 62, 69192 Saint-Fons Cedex, France
Received 17 May 2001; accepted 27 July 2001
Dedicated to Dr Franc¸ois Mathey for his 60th birthday
Abstract
Starting from palladium precursor [Pd(CH3CN)2Cl2], 1-diisopropylaminophospholes give dinuclear complexes, [Pd(phosp-
hole)Cl2]2, which proved to be intermediates in the formation of mononuclear complexes, cis-[Pd(phosphole)2Cl2]. In contrast with
the platinum precursor, only mononuclear complexes, [Pt(phosphole)2Cl2], are obtained with both cis and trans configurations.
These new complexes were fully characterised by X-ray crystallography. © 2002 Elsevier Science B.V. All rights reserved.
Keywords: Phosphole; 1-Diisopropylaminophosphole; Complexes; Palladium; Platinum
As a part of our continuing interest in the design and
synthesis of new phosphole derivatives as ligands for
1. Introduction
applications in catalysis [7], we decided to explore the
The chemistry of phospholes, phosphorus analogue
potential of the 1-diisopropylaminophospholes [8]. The
of the classic five-membered heterocycles, pyrroles,
diisopropylamino group, which possesses different
furans and thiophenes, has been extensively investi-
steric and electronic effects with respect to phenyl
gated and reviewed [1]. Numerous phosphole deriva-
group, may induce different chemical behaviour in or-
tives have been prepared with various substituents at
the ring positions. Among these phosphole derivatives,
ganic chemistry as well as in coordination chemistry.
Here, we report the coordination chemistry of 1-di-
1-phenylphospholes, in particular 3,4-dimethyl-1-
isopropylaminophospholes towards the transition
phenyl-phosphole, have been studied extensively [2].
metals palladium and platinum. This work was sus-
The reason is probably related to the easy preparation
of this phosphole by Mathey’s method of dehydrohalo-
tained by the crystal structures of these new phosphole
complexes,
the
bis[m-chloro-chloro-(1-diisopropy-
genation of the Mc Cormak cycloadduct of 2,3-
dimethylbutadiene and phenyl dichlorophosphine [3].
Although 1-functionalised phospholes, such as 1-
alkoxy- [4], 1-alkylamino- [5], 1-aryl- [4,6] and 1-
alkynyl- [4], could be obtained from 1-phenyl-
phosphole, their coordination properties have received
little attention.
lamino-3,4-diphenylphosphole) palladium(II)] (4), the
cis-dichloro-bis-(1-diisopropylamino-3,4-diphenylphos-
phole) palladium(II) (6), the trans-dichloro-bis(1-diiso-
propylamino-3,4-dimethylphosphole) platinum(II) (7a)
and the trans-dichloro-bis-(1-diisopropylamino-3,4-
diphenylphosphole) platinum (II) (8a).
2. Results and discussion
* Corresponding authors. Tel.: +33-561-333174; fax: +33-561-
553003.
Phospholes which react as a two electron donor
ligands are considered as good s-donors and p-accep-
E-mail addresses: gouygou@lcc-toulouse.fr (M. Gouygou),
daran@lcc-toulouse.fr (J.-C. Daran).
0022-328X/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)01145-7

20
J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
Scheme 1.
fully characterised. The reaction of 1 equivalent of
phosphole 2 with 1 equivalent of [Pd(CH3CN)2Cl2], in
dichloromethane at room temperature led to the imme-
diate formation of complex 4 (l= +48) (Scheme 1).
tors towards Pd(II) and Pt(II) [9]. However, the coordi-
nation ability may be modulated by changing the sub-
stituents on the phosphole ring and/or on the
phosphorus atom. 1-Diisopropylaminophospholes, 1
(R=Me) and 2 (R=Ph), were prepared according to
the new method we recently described [8]. They possess
substituents with different electronic effects at the 3 and
4 position on the phosphole ring. The phosphole 1 was
treated with 1 equivalent of [Pd(CH3CN)2Cl2] in
dichloromethane at room temperature for 4 h. By fol-
lowing the course of the reaction by 31P-NMR, we
observed the disappearance of the signal at l= +28
ppm corresponding to the phosphole 1 concomitant
with the appearance of two low field signals at l= +
49 and +53 ppm corresponding to the formation of
two new complexes in a ratio 25:75. These complexes,
rather unstable, air and moisture sensitive, could not be
separated. However, mass spectroscopy analysis of the
reaction mixture allowed to identify the presence of the
dinuclear complex 3, [Pd(phosphole)Cl2Pd]2, (m/z=
779, [MH+]) and the mononuclear complex 5,
[Pd(phosphole)2Cl2], (m/z=601, [MH+]). Thus, an
equilibrium could exist between these two complexes in
solution as generally observed [10]. On the other hand,
the mononuclear complex 5 (l= +53) could be quan-
titatively obtained from the reaction of an excess of
1
The H- and 31P-NMR spectra were consistent with the
formation of a pure complex which could be isolated in
87% yield as an orange powder. This stable complex 4
is a dinuclear compound as indicated by elemental
analysis, mass spectroscopy and X-ray crystallography.
Although dinuclear complexes are known with bulky
phosphines [10], to the best of our knowledge, complex
4 is the first reported example of a dinuclear palladium
complex containing phosphole as ligand. The molecular
structure of 4, with atom labelling scheme, is presented
in Fig. 1. Selected bond distances and angles are listed
in Table 1. The dinuclear framework presents a sym-
metrical trans structure, the two phosphole ligands are
in trans position with respect to the plane defined by
the Pd and Cl atoms. Each palladium which is bonded
through a double chloro bridge, presents a nearly per-
fect planar arrangement. The largest deviations from
the best planes, Pd(1), P(1), Cl(12), Cl(11), Cl(21), and
phosphole
1
with
palladium
precursor
in
dichloromethane at room temperature (Scheme 1). This
complex which could not be isolated in a pure form,
has been partly characterised. According to 31P- and
1H-NMR analysis, the geometry of this complex should
be square planar with a cis configuration. Indeed, the
doublet observed at l=6.41 (2JH–P=29 Hz) for the
a-methylene resonance is consistent with a cis geometry
in solution [11].
With the phosphole 2, analogous palladium com-
plexes, 4 and 6, have been obtained separately and
proved to be stable. Each of them could be isolated and
Fig. 1. Molecular structure of complex 4. Ellipsoids are drawn at 30%
probability.

J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
Table 1 (Continued)
21
Table 1
,
Selected bond lengths (A) and bond angles (°) for complexes 4, 6, 7a
and 8a
C(111)ꢀN(1)ꢀC(114) 117.24(17) C(211)ꢀN(2)ꢀC(214) 116.03(18)
Complex 8a
Pt(1)ꢀCl(1)
Pt(1)ꢀN(1)
P(1)ꢀC(4)
Complex 4
2.3065(8) Pt(1)ꢀP(1)
2.2908(8)
1.798(3)
1.340(4)
1.338(4)
Pd(1)ꢀP(1)
Pd(1)ꢀCl(12)
Pd(1)ꢀCl(11)
Pd(1)ꢀCl(21)
P(1)ꢀN(1)
P(1)ꢀC(14)
P(1)ꢀC(11)
C(11)ꢀC(12)
C(12)ꢀC(13)
C(13)ꢀC(14)
2.2103(15) Pd(2)ꢀP(2)
2.2829(17) Pd(2)ꢀCl(22)
2.3257(15) Pd(2)ꢀCl(11)
2.4326(14) Pd(2)ꢀCl(21)
2.2079(15)
2.2745(17)
2.4219(14)
2.3303(15)
1.631(5)
1.785(6)
1.788(6)
1.347(8)
1.517(8)
1.652(3)
1.804(3)
1.494(4)
P(1)ꢀC(1)
C(1)ꢀC(2)
C(3)ꢀC(4)
C(2)ꢀC(3)
1.631(5)
1.801(6)
1.803(7)
1.332(8)
1.492(8)
1.356(8)
P(2)ꢀN(2)
Cl(1)ꢀPt(1)ꢀP(1)
Pt(1)ꢀP(1)ꢀN(1)
Pt(1)ꢀP(1)ꢀC(4)
C(1)ꢀP(1)ꢀC(4)
P(1)ꢀN(1)ꢀC(121)
90.17(3) Cl(1)ꢀPt(1)ꢀP(1)%
119.45(9) Pt(1)ꢀP(1)ꢀC(1)
109.57(10) Pt(1)ꢀP(2)ꢀC(21)
90.77(14) P(1)ꢀN(1)ꢀC(111)
89.83(3)
112.86(11)
111.46(7)
115.41(19)
P(2)ꢀC(24)
P(2)ꢀC(21)
C(21)ꢀC(22)
C(22)ꢀC(23)
C(23)ꢀC(24)
127.2(2)
C(111)ꢀN(1)ꢀC(121) 117.3(2)
1.341(8)
Estimated S.D.s in parentheses refer to the last significant digit.
Symmetry transformations used to generate equivalent atoms (%):
−x+1, y, −z+1/2 for 6; −x+2, −y, −z+2 for 8a.
P(1)ꢀPd(1)ꢀCl(12)
P(1)ꢀPd(1)ꢀCl(11)
Cl(12)ꢀPd(1)ꢀCl(11) 175.78(7) Cl(22)ꢀPd(2)ꢀCl(21) 175.25(7)
86.18(6) P(2)ꢀPd(2)ꢀCl(22)
93.69(5) P(2)ꢀPd(2)ꢀCl(21)
86.05(6)
94.27(5)
P(1)ꢀPd(1)ꢀCl(21)
Cl(12)ꢀPd(1)ꢀCl(21) 94.03(6) Cl(22)ꢀPd(2)ꢀCl(11)
Cl(11)ꢀPd(1)ꢀCl(21) 86.14(5) Cl(21)ꢀPd(2)ꢀCl(11)
Pd(1)ꢀCl(11)ꢀPd(2)
N(1)ꢀP(1)ꢀC(14)
N(1)ꢀP(1)ꢀC(11)
C(14)ꢀP(1)ꢀC(11)
N(1)ꢀP(1)ꢀPd(1)
C(14)ꢀP(1)ꢀPd(1)
C(11)ꢀP(1)ꢀPd(1)
179.44(6) P(2)ꢀPd(2)ꢀCl(11)
177.18(6)
93.63(6)
86.28(5)
93.59(5)
114.7(3)
113.5(3)
92.4(3)
112.07(17)
111.22(19)
111.4(2)
,
Pd(2), P(2), Cl(22), Cl(11), Cl(21) is −0.06 A at Cl(12)
93.99(5) Pd(2)ꢀCl(21)ꢀPd(1)
,
and 0.08 A at Cl(22), respectively. The PdꢀP bond
114.4(3)
114.7(3)
92.2(3)
N(2)ꢀP(2)ꢀC(24)
N(2)ꢀP(2)ꢀC(21)
C(24)ꢀP(2)ꢀC(21)
,
lengths (2.216 and 2.200 A) are in good agreement with
the values reported for dinuclear palladium complexes
with other classical phosphines [12]. The phenyl and
phosphole rings are planar within the experimental
error. Both the amino groups PNC2 are planar and
they make a dihedral angle of 46.5° with the phosphole
to which they are attached.
111.01(17) N(2)ꢀP(2)ꢀPd(2)
112.8(2)
110.5(2)
C(24)ꢀP(2)ꢀPd(2)
C(21)ꢀP(2)ꢀPd(2)
C(114)ꢀN(1)ꢀC(111) 117.6(5)
C(111)ꢀN(1)ꢀP(1)
C(114)ꢀN(1)ꢀP(1)
115.8(4)
124.7(4)
The mononuclear palladium complex 6 was obtained
from the dinuclear complex 4 (Scheme 1) by a classical
bridge-cleavage reaction. This was done by the addition
of an excess of phosphole 2 to a dichloromethane
solution of complex 4, leading to the disappearance of
the signal at l= +48 corresponding to the complex 4
and the appearance of a new signal at l= +53 ppm
corresponding to the mononuclear complex 6. As in the
Complex 6
Pd(1)ꢀP(1)
P(1)ꢀN(1)
P(1)ꢀC(4)
N(1)ꢀC(111)
N(1)ꢀC(121)
2.2553(8) Pd(1)ꢀCl(1)
2.3632(8)
1.803(3)
1.341(4)
1.503(4)
1.346(4)
1.649(2)
1.792(3)
1.489(4)
1.482(3)
P(1)ꢀC(1)
C(1)ꢀC(2)
C(2)ꢀC(3)
C(3)ꢀC(4)
P(1)ꢀPd(1)ꢀP(1)%
P(1)ꢀPd(1)ꢀCl(1)%
N(1)ꢀP(1)ꢀPd(1)
C(4)ꢀP(1)ꢀPd(1)
C(1)ꢀP(1)ꢀPd(1)
C(111)ꢀN(1)ꢀP(1)
95.98(4) Cl(1)%ꢀPd(1)ꢀCl(1)
172.06(2) P(1)ꢀPd(1)ꢀCl(1)
113.05(9) N(1)ꢀP(1)ꢀC(4)
120.17(9) N(1)ꢀP(1)ꢀC(1)
101.10(9) C(4)ꢀP(1)ꢀC(1)
123.79(19) C(121)ꢀN(1)ꢀP(1)
90.38(4)
87.30(3)
111.06(12)
119.12(13)
90.50(12)
120.43(18)
1
case of complex 5, the 31P- and H-NMR analyses were
consistent with the formation of a cis square planar
complex in solution. Generally, the trans complex is the
initial formed product of such bridge-cleavage reactions
[13]. Thus, the obtention of the cis complex in this case
might be due to a spontaneous trans–cis isomerisation
[10] in solution at ambient temperature (Scheme 2), the
cis isomer being thermodynamically more stable than
the trans isomer as generally observed for the palladium
phosphole complexes, [Pd(phosphole)2Cl2] [11]. The sta-
ble complex 6, isolated in 96% yield as an orange
powder, was fully characterised by NMR spectroscopy,
mass spectroscopy, elemental analysis and X-ray crys-
tallography. In the solid state, the X-ray analysis confi-
rmed the cis configuration of this complex as shown by
the molecular structure presented in Fig. 2. The
molecule possesses a crystallographic twofold axis go-
ing through the Pd atom which presents a square
planar geometry. However, the coordination sphere
around the Pd atom is somewhat distorted from the
ideal square planar, as underlined by a dihedral angle
of 10.2° between the planes defined by P(1)ꢀPd(1)ꢀP(1%)
C(121)ꢀN(1)ꢀC(111) 115.8(2)
Complex 7a
Pt(1)ꢀCl(1)
Pt(1)ꢀP(1)
2.3110(6) Pt(1)ꢀCl(2)
2.3027(6)
2.3086(5)
1.6531(17)
1.798(2)
1.799(2)
1.347(3)
1.481(4)
1.333(4)
2.3040(5) Pt(1)ꢀP(2)
1.6664(17) P(2)ꢀN(2)
1.8022(19) P(2)ꢀC(21)
P(1)ꢀN(1)
P(1)ꢀC(11)
P(1)ꢀC(14)
C(11)ꢀC(12)
C(12)ꢀC(13)
C(13)ꢀC(14)
1.800(2)
1.337(3)
1.494(3)
1.340(3)
P(2)ꢀC(24)
C(21)ꢀC(22)
C(22)ꢀC(23)
C(23)ꢀC(24)
Cl(1)ꢀPt(1)ꢀCl(2)
Cl(1)ꢀPt(1)ꢀP(1)
Cl(2)ꢀPt(1)ꢀP(1)
Pt(1)ꢀP(1)ꢀN(1)
Pt(1)ꢀP(1)ꢀC(11)
N(1)ꢀP(1)ꢀC(11)
Pt(1)ꢀP(1)ꢀC(14)
N(1)ꢀP(1)ꢀC(14)
C(11)ꢀP(1)ꢀC(14)
P(1)ꢀN(1)ꢀC(111)
P(1)ꢀN(1)ꢀC(114)
176.42(2) P(1)ꢀPt(1)ꢀP(2)
92.39(2) Cl(1)ꢀPt(1)ꢀP(2)
89.82(2) Cl(2)ꢀPt(1)ꢀP(2)
120.24(7) Pt(1)ꢀP(2)ꢀN(2)
111.07(7) Pt(1)ꢀP(2)ꢀC(21)
107.82(9) N(2)ꢀP(2)ꢀC(21)
111.63(7) Pt(1)ꢀP(2)ꢀC(24)
110.85(9) N(2)ꢀP(2)ꢀC(24)
173.937(16)
88.87(2)
89.23(2)
111.78(7)
111.46(7)
114.7(1)
111.70(8)
114.3(1)
91.4(1)
C(21)ꢀP(2)ꢀC(24)
91.48(11)
124.62(15)
119.31(15)
116.44(14) P(2)ꢀN(2)ꢀC(211)
125.14(15) P(2)ꢀN(2)ꢀC(214)

22
J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
Scheme 2.
and Cl(1)ꢀPd(1)ꢀCl(1%). This tetrahedral distortion is
plexes, analogous to palladium complexes 3 and 4.
Complexes 7 and 8 were obtained in solution as a
mixture of cis and trans isomers in a ratio 15:85.
larger than that of the structurally similar dichloro-
bis(3,4-dimethyl-1-phenyl-phosphole)palladium
com-
1
plex [11a] which exhibits an angle of 7.2° between the
Indeed, the 31P- and H-NMR spectra were consistent
analogous plane. The deviations (in A) of the coordi-
with the presence of cis and trans isomers. The 31P{1H}
spectrum showed two signals with for each an overlap-
ping doublet due to the 33.8% of the phosphorus nuclei
coupled to 195Pt. For the major complexes, the value of
,
nated atoms from the plane defined by P2PdCl2 are as
follows: P(1) 0.15; Cl(1) −0.15. The PdꢀP bond length
,
of 2.2553(8) A is slightly longer than that of 2.238(3)
1
1
1
,
and 2.243(3) A found in the dimethyl phosphole com-
the JP–Pt (7a: JP–Pt=2580 Hz, 8a: JP–Pt=2625 Hz)
coupling constants are typical of trans-dichloro-bispho-
,
plex but is similar to the 2.260 and 2.266 A reported for
1
the bis(pyrimidyl)diphenylphosphine complex [14]. The
phenyl and phosphole rings are planar within the exper-
imental error. It is worth to point out that the amino
groups PNC2 which are also planar within the experi-
mental error as in 4, make a dihedral angle of 84.7°
with the phosphole ring.
sphole-platinum complexes whereas the higher JP–Pt
1
1
(7b: JP–Pt=3645 Hz, 8b: JP–Pt=3677 Hz) coupling
constants observed for the minor complex are typical of
cis-dichloro-bisphosphole-platinum complexes [15]. In
1H-NMR, the a-methylene resonances are also consis-
Phospholes 1 and 2 showed similar coordination
behaviour towards palladium(II). These ligands reacted
as two electron-donors to form dinuclear and mononu-
clear complexes. The 31P coordination chemical shifts
values (Dl31P=l31Pcomplex−l31Pligand), in particular
for the mononuclear complexes 5 and 6, which were,
respectively, +25 and +18 and were comparable to
those found for similar phosphole palladium complexes
[9]. Furthermore, it is of interest to note that the value
for complex 6 was smaller than for complex 5. The
small coordination chemical shifts values which
reflected the existence of some p-backbonding between
the palladium and the phosphole were in agreement
with the fact that the ligand 2 with phenyl substituents
in 3 and 4 positions possesses a p-acceptor character
more important than ligand 1 with methyl substituents
in 3 and 4 positions. This p-backbonding could be in
part responsible for the greater stability observed for
complex 6 relative to complex 5.
Fig. 2. Molecular structure of complex 6. Ellipsoids are drawn at 30%
probability.
Slightly different results were obtained with Pt(II).
Phospholes 1 and 2 reacted under the same conditions
with [Pt(CH3CN)2Cl2] precursor at room temperature
in dichloromethane to afford only mononuclear com-
plexes 7 and 8, respectively (Scheme 3). In these cases,
mass spectroscopy of the reaction mixture did not allow
to identify the formation of dinuclear platinum com-
Scheme 3.

J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
23
angles are given in Table 1. The PtꢀP distances,
,
2.3040(5) and 2.3086(5) A, are significantly longer than
the value observed in the cis-3,4-dimethyl-1-phenyl-
phosphole platinum complex [16], 2.239(2) and 2.227(1)
,
A, whereas the PtꢀCl distances are slightly shorter,
,
2.31106(6) and 2.3027(6) A, with respect to the same cis
,
complex, 2.336(2) and 2.360(2) A [15b]. The phenyl and
phosphole rings are planar within the experimental
error. It is interesting to point out that the amino
groups PNC2 which are planar within the experimental
error as in 4 and 6, make a dihedral angle of 84.5 and
75.92° with the corresponding phosphole ring. Such a
conformation, also observed in 6, is found in the free
ligand 1 [8].
In the case of complex 8, the two isomers, separated
1
by fractional crystallisation, were characterised by H-,
Fig. 3. Molecular structure of complex 7a. Ellipsoids are drawn at
30% probability.
31P-, 13C-NMR spectroscopy, mass spectroscopy. The
structure of the trans isomer 8a was determined by
X-ray analysis. A view of this complex with atom
labelling scheme is shown in Fig. 4. The platinum which
is located on an inversion centre presents a nearly
perfect square planar geometry with a Cl(1)ꢀPtꢀP(1%)
angle of 90.17(2)°. Owing to the occurrence of the
inversion centre, the two phosphole rings are located on
each side of this plane. As observed in the other com-
plexes, the amino moiety PNC2 is nearly perpendicular
to the phosphole ring making a dihedral angle of 95.07°
with it.
According to the results obtained with the palladium
complexes, we assumed that the formation of the
mononuclear platinum 7 and 8 complexes as a mixture
of cis and trans isomers proceeded via a dinuclear
complex intermediate (Scheme 2). Then, the bridge-
cleavage reaction by action of a second equivalent of
phosphole led to the formation of the trans isomer
which could isomerise slowly in solution, as generally
observed for this type of platinum complexes [10], to
give a small amount of the cis isomer.
Fig. 4. Molecular structure of complex 8a. Ellipsoids are drawn at
30% probability.
tent with the cis and trans geometry for these complexes
in solution [11a]. The a-methylene resonances appeared
as 1:2:1 triplet in the major trans complexes, those of
the minor cis complexes appeared as 1:1 doublet. In the
case of complex 7, only the trans isomer 7a could be
isolated in 75% yield, as a yellow solid, and it was fully
characterised by 1H-, 31P-, 13C-NMR spectroscopy,
mass spectroscopy and X-ray crystallography. In the
solid state, the X-ray analysis confirmed the trans
configuration of this complex as shown by the molecu-
lar structure presented in Fig. 3. The platinum coordi-
nation geometry is essentially planar with the largest
3. Conclusions
1-Diisopropylaminophospholes 1 and 2 react like
other phospholes to afford square planar palladium(II)
and platinum(II) complexes with trans and/or cis
configuration. However, the steric and electronic effects
of the diisopropylamino group on the phosphorus posi-
tion allow the formation of dinuclear complexes which
have been characterised for the first time in the case of
palladium and the electronic effects of the 3,4 sub-
stituents on the phosphole ring seem to influence the
stability of these complexes. In addition, these dinuclear
complexes appear to be intermediates in the formation
of the mononuclear square planar complexes. Further
studies are in progress in order to test the catalytic
,
deviation from the square plane being 0.03 A. The
N(1)ꢀP(1)ꢀP(2)ꢀN(2) torsion angle is 11.5° which
clearly indicates that the two phosphole rings are lo-
cated on the same side of this plane. A similar arrange-
ment was observed for the trans related 3,4-dimethyl-1-
phenyl-phosphole palladium complex [11b]. The PtꢀP
and PtꢀCl bond lengths reflect the respective trans
position of the ligands. Important bond distances and

24
J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
activity of these new palladium and platinum mononu-
clear complexes.
12H, CH3); 3.85 (m, 4H, (CH3)2CH); 6.41 (d, JHP
29.0 Hz, 4H, CHP).
=
4.4. cis-Dichloro-bis(1-diisopropylamino-
3,4-diphenylphosphole) palladium(II) (6)
4. Experimental
4.1. General
To a solution of palladium complex 4 (0.600 g, 0.58
mmol) in CH2Cl2 (10 ml) was added a solution of
phosphole 2 (0.392 g, 1.16 mmol) in CH2Cl2 (2 ml). The
resulting mixture was stirred at r.t. for 24 h, filtered
through a 0.45 mm PTFE filter and then concentrated
under reduced pressure to give a solid residue. This
resulting solid was then dissolved in a small amount of
CH2Cl2 and precipitated with a large excess of pentane.
After filtration, the orange solid obtained was dried
under vacuum. Yield: 0,944 mg (96%). 31P-NMR
(CDCl3): l +53.5. 1H-NMR (CDCl3) l: 1.03 (d,
All reactions were carried out under an inert atmo-
sphere of dry Ar by using Schlenk glassware and vac-
uum line techniques. 1-Diisopropylaminophospholes, 1
and 2, was prepared as described in the literature [8].
Solvents were freshly distilled from standard drying
agents. 1H-, 31P{1H}- and 13C{1H,31P}-NMR spectra
were recorded in a Bruker AM 250 instrument operat-
ing at 250, 101, and 63 MHz, respectively. Chemical
shifts are reported in parts per million (ppm) relative to
Me4Si (1H and 13C) or 85% H3PO4 (31P). Mass spectra
were obtained in a Mermag R10-10 instrument. Ele-
mental analysis were performed by the ‘service
d’analyse du Laboratoire de Chimie de Coordination’
at Toulouse.
J
HH=6.25 Hz, 24H, (CH3)2CH); 3,88 (m, 4H,
(CH3)2CH); 7.06 (d, 4H, JHP=27.1 Hz, CHP) 7.12 (m,
6H, Ph), 7.34–7.24 (m, 14H, Ph). 13C-NMR (CDCl3): l
23.0 (s, 2C, (CH3)2CH); 53.0 (d, CP=6 Hz,
6
J
(CH3)2CH); 128.1–128.8 (m, Ph); 135.6 (d, JC–P=15.5
Hz, Cipso); 151.2 (b, CPh). DCIMS (NH3); m/z (%): 849
(24%) [MH+]. Anal. Found: C, 62.59; H, 6.52; N, 3.12.
Calc. for C44H52Cl2N2P2Pd (848.2): C, 62.31; H, 6.18;
N, 3.30%. Crystals suitable for X-ray analysis were
obtained by slow evaporation of a CH2Cl2 solution.
4.2. Bis[v-chloro-chloro-(1-diisopropylamino-
3,4-diphenylphosphole)palladium(II)] (4)
A CH2Cl2 solution (5 ml) of phosphole 2 (0.210 g,
0.63 mmol) was added to a stirred suspension of
[PdCl2(CH3CN)2] (0.080 g, 0.31 mmol) in CH2Cl2 (10
ml). The resulting mixture was stirred at room tempera-
ture (r.t.) for 24 h, filtered through a 0.45 mm PTFE
filter and then concentrated under reduced pressure to
give an orange solid residue. The solid was then washed
three times with pentane, filtered and dried under vac-
uum. Yield: 0.230 g (87%). 31P-NMR (CDCl3): l +
4.5. trans-Dichloro-bis(1-diisopropylamino-
3,4-dimethylphosphole) platinum(II) (7a)
To a solution of phosphole 1 (0.200 g, 0.99 mmol) in
CH2Cl2 (10 ml) was added solid [Pt(CH3CN)2Cl2]
(0.176 g, 0.44 mmol). The reaction mixture turned
yellow immediately. After 1 h of stirring at r.t., the
resulting solution was filtered through a 0.45 mm PTFE
filter, and then evaporated. The yellow solid obtained
was washed with pentane and dried in vacuo. Yield:
1
48.8. H-NMR (CDCl3): l 1.32 (d, JHH=6.3 Hz, 24H,
(CH3)2CH); 4.16 (m, 4H, (CH3)2CH); 6.80 (d, JHP
=
29.8 Hz, 4H, CHP); 7.46–7.05 (m, 20H, Ph). 13C-NMR
(CDCl3): l 23.0 (s, (CH3)2CH); 51.7 (s, (CH3)2CH);
125.6–128.0 (m, Ph); 128.75 (d, JCꢀP=21 Hz, CHP);
135.3 (d, JCP=16.7 Hz, Cipso); 149.8 (d, JCP=18.6 Hz,
CPh). DCIMS (CH4); m/z (%): 1044 (100%) [MCH+5 ].
Anal. Found: C, 51.21; H, 4.33; N, 2.71. Calc. for
C44H52Cl4N2P2Pd2 (1025.5): C, 51.54; H, 5.11; N,
2.73%. Crystals suitable for X-ray analysis were ob-
tained by slow evaporation of a CH2Cl2 solution.
1
0.130 mg (75%). 31P-NMR (CDCl3): l 44.6. H-NMR
(CDCl3): l 1.18 (d, JHH=6.8 Hz, 24H, (CH3)2CH);
1.94 (s, 12H, CH3); 4.04 (m, 4H, (CH3)2CH); 6.39 (t,
J
HP=31.6 Hz, 4H, CHP). 13C{1H}-NMR (CDCl3): l
17.74 (s, CH3); 23.25 (s, (CH3)2CH); 50.0 (s,
(CH3)2CH); 124.4 (t, JCP=60.8 Hz, CHP); 147.5 (t,
J
CP=19.0 Hz, CCH3). DCIMS (NH3); m/z (%): 689
(64) [MH+]. Yellow crystals suitable for X-ray were
obtained by slow evaporation of a CH2Cl2 solution.
4.3. cis-Dichloro-bis(1-diisopropylamino-3,4-
dimethylphosphole) palladium(II) (5)
4.6. cis- and trans-Dichloro-bis(1-diisopropylamino-
3,4-diphenylphosphole) platinium(II) (8)
The same procedure as described for 4 was used.
Starting from
1
(0.145 g, 0.63 mmol) and
[PdCl2(CH3CN)2] (0.073 g, 0.28 mmol), 5 was obtained
as an orange solid. Yield: 0.130 g (80%). 31P-NMR
(CDCl3): l +53.2. 1H-NMR (CDCl3): l 1.18 (d,
The procedure was analogous to that for 7. The
resulting solution was filtered through a 0.45 mm PTFE
filter, concentrated to ꢀ5 ml under reduced pressure
and slow addition of ꢀ10 ml of pentane gave the cis
JHH=6.8 Hz, 24H, (CH3)2CH); 2.02 (d, JHP=7.5 Hz,

J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
25
complex 8b as a yellow solid which was isolated by
filtration, washed with pentane and dried under vac-
uum. The trans complex 8a was obtained as a yellow
powder by evaporation of the filtrate. Crystals were
grown from a CH2Cl2 solution of the compound. 8a:
Yield: (62%). 31P-NMR (CDCl3): l 46.65. 1H-NMR
(CD2Cl2): l 1.30 (d, JHH=6.8 Hz, 24H, (CH3)2CH);
4.25 (m, 4H, (CH3)2CH); 6.90 (t, JHP=27.3 Hz, 4H,
CHP); 7.00–7.25 (m, 20H, Ph). 13C-NMR (CDCl3): l
23.23 (s, (CH3)2CH); 51.4 (s, (CH3)2CH); 128.5–127.9
data collections. The structure was solved by direct
methods (SIR97 [16]) and refined by least-squares proce-
dures on F2. All H atoms attached to carbon were
introduced in calculation in idealised positions
,
[d(CH)=0.96 A] and treated as riding models. In
complex 4, the refinement of Flack’s parameter did not
allow to define properly the absolute structures and the
occurrence of a twin by inversion (racemic twin) had to
be considered. Moreover in this complex, two of the
isopropyl groups are disordered over two positions.
These disordered groups were treated using the avail-
able tools in SHELXL-97 [17]. Least-squares refinements
were carried out by minimising the function ꢀ w(F2o−
F2c)2, where Fo and Fc are the observed and calculated
structure factors. The weighting scheme used in the last
refinement cycles was w=1/[|2(Fo2)+(aP)2+bP]
where P=(F2o+2F2c)/3. Models reached convergence
with R=ꢀ(ꢁꢁFoꢁ−ꢁFcꢁꢁ)/ꢀ(ꢁFoꢁ) and wR2={ꢀ w(F2o−
F2c)2/ꢀ w(Fo2)2}1/2, having values listed in Table 2. The
calculations were carried out with the SHELXL-97 pro-
gram [16] using the integrated system WINGX (1.63)
[18]. Molecular view was realised with the help of
ORTEP [19].
(m, Ph); 129.5 (t, JCP=59.4 Hz, CHP); 149.5 (t, JCP
=
20.3 Hz, CPh). DCIMS (NH3); m/z (%): 937 (100)
[MH+].
8b: Yield: (10%). 31P-NMR (CDCl3): l 33.38. 1H-
NMR (CD2Cl2): l 1.06 (d, JHH=6.8 Hz, 24H,
(CH3)2CH); 3.90 (m, 4H, (CH3)2CH); 6.89 (d, JHP
=
27.3 Hz, 4H, CHP); 7.07–7.32 (m, 20H, Ph). DCIMS
(NH3); m/z (%): 937 (100) [MH+].
4.7. X-ray crystallographic study
Data for 4 were collected on a Bruker Smart 1000
diffractometer whereas a Stoe IPDS (imaging plate
diffraction system) diffractometer was used for com-
pounds 6, 7a and 8a. The final unit cell parameters were
obtained by the least-squares refinement of a large
number of reflections (10 936 for the Smart and 8000
for the IPDS). Only statistical fluctuations were ob-
served in the intensity monitors over the course of the
5. Supplementary material
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Table 2
Crystal data and structural refinement parameters for complexes 4, 6, 7a and 8a
4
6
7a
8a
Empirical formula
Formula weight (g)
Temperature (K)
Crystal system
Space group
Unit cell dimensions
C44H50Cl4N2P2Pd2
1023.4
193(2)
Orthorhombic
Pna21
C23H28Cl3NPPd0.5
508.98
160(2)
Monoclinic
C2/c
C24H44Cl2N2P2Pt
688.54
160(2)
Monoclinic
P21/c
C22H26ClNPPt0.5
468.40
180(2)
Triclinic
(
P1
,
a (A)
22.1650(7)
8.1645(3)
24.7373(8)
23.345(5)
8.573(2)
24.282(5)
17.928(2)
12.685(1)
13.312(1)
8.3402(11)
11.4597(14)
12.2203(15)
79.72(1)
73.45(2)
73.74(1)
1068.6(2)
2
1.456
35.14
5.26B2qB52.18
10 509
3874 (0.0299)
3237
,
b (A)
,
c (A)
h (°)
i (°)
107.74(3)
101.92(1)
k (°)
3
,
U (A )
4476.6(3)
4
1.518
11.46
3.30B2qB52
48 639
8780 (0.0670)
7669
0.0396, 0.0954
0.0510, 0.1068
0.016
4628.6(17)
8
1.461
8.51
5.1B2qB48.3
17 946
3504 (0.0476)
3237
0.0328, 0.0848
0.0357, 0.0876
0.001
2962.1(5)
4
1.544
50.40
4.74B2qB51.9
22 683
5716 (0.0324)
5349
0.0179, 0.0434
0.0202, 0.0441
0.002
Z
Dcalc (g cm−3
)
v (Mo–Ka) (cm−1
2q range (°)
)
Reflections measured
Independent reflections (Rint
Reflections used (I\2|(I))
R, wR2 [I\2|(I)]
R, wR2 (all data)
(Z/|)max
)
0.0207, 0.0541
0.0210, 0.0607
0.001
Dzmin/Dzmax
Goodness-of-fit
−0.59/1.62
1.154
−1.02/1.12
1.032
−0.45/0.54
1.057
−1.14/1.71
1.120
Variable parameters
492
262
292
236

26
J. Hydrio et al. / Journal of Organometallic Chemistry 643–644 (2002) 19–26
(d) O. Tissot, J. Hydrio, M. Gouygou, F. Dallemer, J.-C. Daran,
G.G.A. Balavoine, Tetrahedron 56 (2000) 85;
(e) J. Hydrio, M. Gouygou, F. Dallemer, J.-C. Daran, G.G.A.
Balavoine, J. Organomet. Chem. 595 (2000) 261.
[8] J. Hydrio, M. Gouygou, F. Dallemer, J.-C. Daran, G.G.A.
Balavoine, submitted for publication.
Data Centre, CCDC nos. 163288–163291 for com-
pounds 4, 6, 7a and 8a, respectively. Copies of this
information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge CB2
1EZ, UK (Fax: +44-1223-336033; e-mail: deposit@
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
Tables of anisotropic temperature factors, hydrogen
coordinates and observed and calculated structure fac-
tors are available from the Cambridge Crystallographic
Data Centre. Ordering information is given on any
current masthead page.
[9] (a) F. Mathey, J. Fischer, J.H. Nelson, Struct. Bonding 55 (1983)
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