Synthesis of palladium and platinum donor complexes and study of their participation in self-assembly reactions. X-ray crystal structure of [Pt(C 6H4C≡CC5H4N) 2(dppp)] (dppp = 1,3-bis(diphenylphosphin

Article abstract of DOI:10.1016/j.jorganchem.2005.01.007

Novel square-planar compounds [M(NC₅H₄C≡CH) ₂(dppp)](OTf)₂ (M = Pd (1), Pt (2)), [Pt(C≡CC ₆H₄CN)₂(dppp)] (3) and [Pt(C₆H ₄C≡CC₅H₄N)

Full text of DOI:10.1016/j.jorganchem.2005.01.007

Journal of Organometallic Chemistry 690 (2005) 1612–1619
www.elsevier.com/locate/jorganchem
Synthesis of palladium and platinum donor complexes
and study of their participation in self-assembly reactions.
X-ray crystal structure of [Pt(C6H4C„CC5H4N)2(dppp)]
(dppp = 1,3-bis(diphenylphosphino)propane)
a,
Montserrat Ferrer , Laura Rodrıguez , Oriol Rossell , Xavier Solans
a
a
b
*
´
a
´
Departament de Quımica Inorganica, Universitat de Barcelona, Martı i Franques 1-11, 08028 Barcelona, Spain
´
`
`
b
´
`
`
Departament de Cristal Æ lografia, Mineralogia i Diposits Minerals, Universitat de Barcelona, Martı i Franques s/n, 08028 Barcelona, Spain
Received 16 November 2004; accepted 4 January 2005
Abstract
Novel square-planar compounds [M(NC5H4C„CH)2(dppp)](OTf)2 (M = Pd (1), Pt (2)), [Pt(C„CC6H4CN)2(dppp)] (3) and
[Pt(C6H4C„CC5H4N)2(dppp)] (4) (dppp = 1,3-bis(diphenylphosphino)propane) were prepared and characterised. Their potential
as building blocks in the generation of heterobimetallic squares was studied. The reaction of 4 and the ditopic acceptor species
[Pd(H2O)2(dppf)](OTf)2 enabled a tetrametallic metallocycle containing two platinum and two palladium atoms to be obtained.
The crystal X-ray structure of 4 shows that the Ptꢀ ꢀ ꢀN vectors are nearly perpendicular, and confirm the suitability of the compound
to act as a corner unit for the construction of molecular squares.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Supramolecular chemistry; Self-assembly; Metalloligand; Platinum; Palladium; Diphosphine
1. Introduction
other, with a cis-square planar metal complex having
two adjacent weakly labile ligands X, such as triflate
or nitrate, as well as a bidentate ligand (Scheme 1(a)).
In general, self-assembly reactions to form molecular
squares proceed most efficiently under conditions of
high dilution since increased concentrations afford poly-
meric species. Although a huge number of homometallic
species prepared by this method have been described so
far [3], the synthesis of heterometallic molecular squares
requires some modifications. In the latter case, the linker
L could be replaced by: (i) a cis-square planar or octahe-
dral metal complex with two ligands L0, able to react
through a donor atom located at the unbounded end,
or (ii) a metal complex having at least two ligands L0
containing reactive sites at a 180ꢁ angle from each other.
Briefly, two transition metal complexes should be used:
one to act as acceptor [MX2(bidentate)], and the other,
The preparation of organised nanostructures based
on molecular self-assembly, employing coordination as
motif, has undergone rapid growth and aroused wide-
spread interest in recent years [1]. In particular, transi-
tion-metal directed self-assembly has been used to
construct a number of 2D polygons, as well as more
complex structures [2].
A general strategy for the construction of palladium-
or platinum-containing molecular squares consists of
the reaction of a linear ditopic organic ligand L, that
contains two reactive sites at a 180ꢁ angle from each
*
Corresponding author. Tel.: + 34 93 402 1271; fax: +34 93 490
7725.
E-mail address: montse.ferrer@qi.ub.es (M. Ferrer).
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.01.007

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
1613
(l-dppm)2(l-O2CC5H4N)2] [10]. Interestingly, the
obtention of other heterobimetallic square molecular
compounds following related strategies has been
reported [11]. Given that palladium- or platinum-
containing square molecular complexes are relevant to
homogeneous catalysis and materials science and pro-
cesses such as molecular recognition, we undertook
our study in order to gain insight into this growing field.
Here we report the synthesis of the new ‘‘metalloligand’’
species [M(NC5H4C„CH)2(dppp)](OTf)2, [Pt(C„
CC6H4CN)2(dppp)] and [Pt(C6H4C„CC5H4N)2(dppp)]
(M = Pd, Pt; dppp = 1,3-bis(diphenylphosphino) pro-
pane), and the study of their use as building blocks for
the synthesis of new heterobimetallic molecular squares.
8+
(a)
M
L
M
M
X
X
+
L
8 X-
L
+
L
M
L
M
(b)
4+
M'
L'
M
M' L'
L'
M
X
X
+
L'
L'
+ 4 X-
2. Results and discussion
M
L'
M'
2.1. Synthesis and characterisation
8+
The cationic compounds [M(NC5H4C„CH)2(dppp)]
(OTf)2 (M = Pd (1), Pt (2); dppp = 1,3-bis(diphenyl-
phosphino)propane) were synthesised by displacement
of the aqua ligands from [M(H2O)2(dppp)](OTf)2 by 4-
ethylnylpyridine in THF at room temperature. 1 and 2
were isolated as white solids in excellent yields (Scheme
2(a)). The preparation of [Pt(dppp)(C„C- C6H4CN)2]
(3) and [Pt(dppp)(C6H4C„CC5H4N)2] (4) required the
M
M
L' M' L'
L'
M'
L
L'
M'
L'
M
X
X
8 X-
+
L'
M'
L'
+
L' M' L'
M
M'
= bidentate ligands
n
prior generation, by treatment with BuLi in THF at
X = labile ligand
L = ditopic ligand
ꢂ78 ꢁC, of the organolithium derivatives from 4-eth-
ynylbenzonitrile and 4-(4-bromophenylethynyl)pyridine,
respectively, followed by the addition of solid
[PtCl2(dppp)] (Scheme 2(b)). In both cases, a pale yellow
solid was isolated in moderate yields.
L' = ligand with a terminal donor
atom
Scheme 1.
Evidence for the proposed structures was obtained
from IR, 1H and 31P NMR spectroscopies, ESMS
and FABMS spectrometries, elemental analyses and
the X-ray crystal structure determination for com-
pound 4. The IR spectra of 1–4 shows a C„C band
(at about 2110 cmꢂ1 for 1–3 and at 2207 cmꢂ1 for 4)
shifted to higher frequencies (10–20 cmꢂ1) than that
of the organic ligand. The C„N stretch for 3 appears
within the expected range (2223 cmꢂ1). Interestingly, 1
and 2 show a band at 3233 and 3230 cmꢂ1, respec-
tively, that evidences the presence of a terminal acety-
lenic proton. In all cases, the 31P NMR spectrum
displays, as expected, only one signal, flanked by plat-
either cis-½M0L20 (other ligands)], ½M0L20 ꢁ or trans-½M0L02
(other ligands)], as donor. The self-assembly of both
species will lead to heterobimetallic squares (Scheme
1(b)).
The limitation of the latter method arises from the
lack of this kind of donor species or ‘‘metalloligands’’,
since in most cases, these complexes have to be specially
designed to act as suitable building blocks in self-assem-
bly reactions with the already described bis(triflate)
or bis(nitrate) platinum and palladium complexes. As
a result, there are far fewer palladium or platinum-
containing heterobimetallic molecular squares than
homometallic ones. To our knowledge, only a small
number of compounds have been used in the prepara-
tion of the desired heterobimetallic metallacycles:
[Pt(C6H4CN)2(dppp)], [Pt(C„CC5H4N)2(L)] (L =
dppp, DIOP) [4], [Ti(g-C5H5)(O2CC5H4N)2] [5], [Ru-
(pyterpy)2(PF6)2] [6], fac-[ReCl(CO)3(N-N)2] [7],
[Ru(2,20-bipy)2(N–N)]Cl2 [8], trans-[PtI2(CNC6H2-
(i-Pr)2-2,6-(C„CC5H4N-4)-4)2] [9] and cis-[Re2Cl2-
1
inum satellites for 2–4. The H NMR spectrum con-
firms the coordination of 4-ethynylpyridine in 1 and
2 since the Ha of the pyridine ring shifted 0.4 ppm
downfield relative to the same signals in the free organ-
ic ligand. Curiously, the Hb shifted upfield from
d = 7.41 ppm in the free organic molecule to d = 7.25
ppm in 1 or 7.07 ppm in 2. In addition, the acetylenic
proton appeared at about 4.3 ppm for both com-
pounds. This resonance is not present in the spectrum

1614
M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
(a)
2+
P
P
M
N
N
C
C H
(OTf)2
THF
RT
M(H2O)2(dppp) (OTf)2
+
2
C
C H
N
C
M = Pd, 1
M = Pt, 2
C
H
(b)
THF
RX
+
nBuLi
R-Li+
+
nBuX
-78ºC
P
P
2 R-Li+
+ 2 LiCl
P
Pt
Cl
+
P
Pt
R
R
Cl
for X = H, R =
for X = Br, R =
C
C
CN
3
C
C
N
4
Scheme 2.
of 3, confirming the coordination to platinum of the
alkynyl ligand through the carbon atom. On the other
hand, 4 shows the two signals of the pyridinic protons,
Ha (d = 8.47 ppm) and Hb (d = 7.20 ppm) shifted
slightly upfield from the values found for 4-bromophe-
nyl-4-ethynylpyridine (d = 8.63, 7.48 ppm). In this case,
as both kinds of protons remain far from the metal
centre, the coordination process affects them much less.
The ESMS spectra detected the molecular peaks at
m/z 362.0 for 1 and m/z 406.2 for 2, while those for 3
(m/z 859.6 [M + H+]) and 4 (m/z 964.2 [M + H+]) were
obtained from FABMS experiments. The structure of
4 was confirmed by an X-ray crystal structure determi-
nation. Single crystals suitable for X-ray crystallography
were grown from dichloromethane/diethylether.
The structure of the platinum complex is shown in
Fig. 1; selected bond distances and angles are listed in
Table 1.
Fig. 1. Molecular structure of 4.
The molecule shows the expected cis-arrangement for
the 4-(4-pyridylethynyl)phenyl ligands (C(1)–Pt–C(1_2)
86.4(7)ꢁ; P–Pt–P_2 93.55(18)ꢁ), as imposed by the pres-
ence of the chelating dppp ligand. The organic ligand
is essentially linear (C(4)–C(7)–C(8) 177.5(7)ꢁ; C(7)–
C(8)–C(9) 177.2(8)ꢁ) and the bond angle between the
phosphorus and the organic ligand is C(1)–Pt–P
90.0(3)ꢁ, as expected for a square-planar Pt(II) centre.
Table 1
˚
Selected bond distances (A) and angles (ꢁ) for 4
Pt–C(1)
Pt–P
2.042(13)
2.308(3)
1.189(9)
93.55(18)
86.4(7)
C(7)–C(8)
P–Pt–P_2
C(1)–Pt–C(1_2)
C(1)–Pt–P_2
C(7)–C(8)–C(9)
C(4)–C(7)–C(8)
P–Pt–C(1)
˚
The C(7)–C(8) triple bond distance, 1.189(9) A, com-
176.3(4)
177.2(8)
177.5(7)
90.0(3)
pares well with those reported earlier for similar acety-
lenic moieties [12]. The Pt. . .N vectors are nearly
perpendicular to one another, confirming that this unit

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
1615
Fig. 2. Stacking diagram of 4.
4ꢂ
represents a suitable corner for the construction of plat-
inum-containing squares.
ðdppeÞꢁ
in the reaction between [PPN][Au(acac)2]
4
and [Pt(C„C–C„CH)2(dppe)], prompted us to try the
‘‘acac’’ method [14] to synthesise the Pd, Pt/Au heterobi-
metallic molecules that we were looking for. This strat-
egy required the use of the new cationic complexes 1 and
2. Thus, 1 and 2 were reacted with [PPh4][Au(acac)2] in
dichloromethane. The reaction was monitored by 31P
NMR and, after 30 min of stirring, the formation of a
Especially interesting is the stacking pattern in the so-
lid state, as shown in Fig. 2. The square-planar mole-
cules of 4 are stacked along the c-axis. A platinum
atom is located at each of the eight vertices of the unit
cell and at the centre of the bc faces. The shortest plat-
˚
inum–platinum distance is 9.71 A, which excludes me-
tal–metal interactions.
1
new species (d = ꢂ10.8 ppm, J(Pt–P) = 3502 Hz) that
It is noteworthy that none of the reported similar
compounds [13] shows this type of molecular packing.
did not contain 4-pyridylacetylene ligand was observed,
accompanied by gold deposition. Given that, according
to NMR data, the new species was probably [Pt-
(acac)(dppp)](OTf), we tried to confirm its nature by
reacting 2 with Tl(acac). Indeed, the resulting compound
showed the same spectroscopic data, confirming our
hypothesis. The use of 1 did not give the desired
product.
2.2. Use of 1–4 as building blocks for the formation of
metallacycles
It is well known that acetylide gold complexes can be
easily obtained by the reaction of [PPh4][Au(acac)2] with
terminal alkyne ligands [14]. Following this strategy we
recently published the synthesis of new linear ditopic
acetylide gold complexes of the type [PPh4][Au(Alk)2]
(Alk = py–C„C–, py–C„C–C6H4–C„C– and others)
that were reacted with the acceptor units
[M(OTf)2(diphosphine)] (M = Pd, Pt) in an attempt to
obtain square molecular polygons containing palladium
or platinum and gold [15]. However, in all cases, only
intractable and insoluble materials were formed. The
formation of polymers, even in high dilution conditions,
prevailed over that of metallacycles.
In view of these results, we investigated the possibility
of forming heterobimetallic polygons using 3 and 4. The
topology of these molecules makes them appropriate for
carrying out reactions with acceptor corner units. 3, for
which an alternative synthetic strategy was reported in
the course of this work [3m], was reacted with
[Pd(H2O)2(dppp)](OTf)2 in dichloromethane at room
temperature. However, we were unable to isolate the ex-
pected molecular square in spite of numerous changes in
reaction conditions involving solvents, reaction times,
solution concentrations and temperatures. On the other
hand, the use of 4 gave better results. Indeed, 4 was re-
acted with [Pd(H2O)2(dppf)](OTf)2 in CH2Cl2 at room
temperature Eq. (1).
These unsuccessful results together with the report by
Bruce et al. [16], who had evidence of the formation
of the square ½Ptðl-CBCꢂCBCAuCBCꢂCBCÞ-

1616
M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
ð1Þ
The process was monitored by 31P NMR spectros-
phosphine ligands with their expected integration, as
well as the protons of the organic ligand (see Section
3). The two expected resonances for the Cp protons
of dppf appear at 4.73 and 4.58 ppm. Again, the Ha
of the pyridine ligand (d = 8.55 ppm) shifted downfield
about 0.1 ppm from the values of 4 and can be used as
a diagnostic tool for confirming the coordination of the
metalloligand. FABMS spectrum of 5 contains the
molecular peak at m/z 811.9 [(M ꢂ 4OTf)4+], providing
further evidence of the formation of the molecular
square.
In conclusion, although attempts to prepare heterobi-
metallic square complexes of palladium or platinum
using the new donor corners 1, 2 and 3 have been unsuc-
cessful to date, the coordination ability of the pyridinic
nitrogen atoms in compound 4, together with its suitable
topology, enabled us to synthesise a tetrametallic square
containing two platinum and two palladium atoms. This
promising result encourage us to extend our investiga-
tions to other transition metal building blocks in order
copy. After 1 h of stirring, the solution was concentrated
and the addition of diethylether gave compound 5 as a
red solid, which was spectroscopically characterised.
The 31P NMR spectrum (Fig. 3) showed unambiguously
the formation of 5: the signal at d 31P = 31.1 ppm is as-
signed to the phosphorus atoms coordinated to palla-
dium; while the resonance at ꢂ3.4 ppm, flanked by
195Pt satellites (J(Pt–P) = 1719 Hz), is due to the phospho-
rus atoms linked to platinum.
It should be noted that the phosphorus resonance of
the palladium complex shifts about 15 ppm upfield on
coordination ( d 31P = 45.6 ppm for [Pd(H2O)2(dppf)]-
(OTf)2); in contrast, the signal due to the platinum
complex only shifts 1 ppm relative to the starting com-
plex because the platinum environment is scarcely
modified after coordination. As observed in the spec-
trum, the reaction is very clean and yields the product
1
in excellent yields. On the other hand, the H NMR
spectrum showed the signals of the protons of both
38
34
30
26
22
18
14
10
6
-2
-6
-10
-14
-18
2
(ppm)
Fig. 3. 31P NMR spectrum of 5.

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
1617
to construct new heterobimetallic assemblies with poten-
tially wide applications.
3.3. Synthesis of [Pt(4-cyanophenylethynyl)2(dppp)]
(3)
To a precooled (ꢂ78 ꢁC) solution of 4-ethynylbenzo-
n
nitrile (58 mg, 0.44 mmol) in THF (15 ml), BuLi (0.28
3. Experimental
ml, 0.44 mmol) was added dropwise. The solution
turned pale yellow immediately. After 1 h of stirring, so-
lid [PtCl2(dppp)] (100 mg, 0.14 mmol) was added and
the solution was allowed to warm slowly to room tem-
perature. The solution was concentrated to dryness.
The pale green residue was extracted with toluene
(3 · 10 ml) and the resulting filtrates were combined,
evaporated to dryness and washed with diethylether. A
pale yellow solid was obtained in 65% yield after recrys-
tallisation with dichloromethane/diethylether. IR (KBr,
cmꢂ1): 2223 m, m(C„N); 2113 m, m(C„C). 31P{1H}
NMR (298 K, THF, inset acetone-d6 with 1% POMe3):
ꢂ7.2 (s, JPt–P = 2173 Hz). H NMR (298 K, CDCl3):
7.59 (d, JH–H = 8.5 Hz, 4H, CN–C6H2,oH2,m), 7.40–
7.36 (m, 20H, Ph), 6.81 (d, 4H, CN–C6H2,oH2,m), 2.53
(s, br, 4H, P–CH2), 2.24 (m, 2H, P–CH2–CH2).
FAB(+) m/z; [ M + H+]: Calc.: 859.1; Found: 859.6;
[(M ꢂ 4-ethynylbenzonitrile)+]: Calc.: 733.1; Found:
733.8. Anal. Calc.: C, 62.86; H, 3.95; N, 3.26. Found:
C, 62.90; H, 3.97; N, 3.28.
All manipulations were performed under prepurified
N2 using standard Schlenk techniques. All solvents were
distilled from appropriate drying agents. Infrared spec-
tra were recorded on a FT-IR 520 Nicolet spectropho-
tometer. 31P{1H} NMR (d(85% H3PO4) = 0.0 ppm)
and 1H NMR (d(TMS) = 0.0 ppm) spectra were ob-
tained on a Bruker DXR 250 and Varian Gemini 200
spectrometers. Elemental analyses of C, H, N and S
´
`
were carried out at the Serveis Cientıfico-Tecnics in Bar-
celona. FAB(+) and Electrospray mass spectra were re-
corded on a Fisions VG Quattro spectrometer. The
compounds [PtCl2(dppp)] [17], [Pt(H2O)2(dppp)](OTf)2
[18], [Pd(H2O)2(dppp)](OTf)2 [18], [Pd(H2O)2(dppf)]-
(OTf)2 [19], 4-ethynylpyridine [20], 4-ethynylbenzonitrile
[21] and 4-(4-bromophenylethynyl)pyridine [22] were
prepared as described elsewhere.
1
1
3.1. Synthesis of [Pd(dppp)(4-ethynylpyridine)2](OTf)2
(1)
Solid 4-ethynylpyridine (6 mg, 0.06 mmol) was added
to a THF (10 ml) solution of [Pd(H2O)2(dppp)](OTf)2
(23 mg, 0.03 mmol) at room temperature. After 1 h of
stirring the solution was concentrated to 3 ml under vac-
uum. The addition of pentane (35 ml) caused the precip-
itation of the product (1) as a white solid, which was
filtered and vacuum-dried. Yield: 98%. IR (KBr,
cmꢂ1): 3233 m, m(C–H); 2115 m, m(C„C); 1260 vs,
1157 m, 1101 m, 1029 vs, (OTfꢂ). 31P{1H} NMR (298
3.4. Synthesis of [Pt(4-(4-pyridylethynyl)phenyl)2-
(dppp)] (4)
To a precooled (ꢂ78 ꢁC) solution of 4-(4-bromophen-
ylethynyl)pyridine (114 mg, 0.44 mmol) in THF (15 ml),
nBuLi (0.28 ml, 0.44 mmol) was added dropwise and the
pale yellow solution turned dark green immediately.
After 1 h of stirring at ꢂ78 ꢁC, solid [ PtCl2(dppp)]
(100 mg, 0.15 mmol) was added and the solution was al-
lowed to warm slowly to room temperature. After 3
days of stirring, the solution was concentrated to dry-
ness and extracted with hot toluene (3 · 10 ml). A pale
yellow solid was obtained in 13% yield after recrystalli-
sation with dichloromethane/diethylether. IR (KBr,
cmꢂ1): 2207 s, 2151 w, m(C„C). 31P{1H} NMR (298
K, THF, inset acetone-d6 with 1% POMe3): ꢂ2.4 (s,
1
K, THF, inset acetone-d6 with 1% POMe3): 6.0 (s). H
NMR (298 K, acetone-d6): 9.05 (m, 4H, Ha–pyr), 7.85–
7.33 (m, 20H, Ph), 7.25 (m, 4H, Hb–pyr), 4.35 (s, 2H,
C„CH), 3.43 (s, br, 4H, P–CH2), 2.32 (m, 2H,
PCH2CH2). ES(+) m/z; [M2+]: Calc.: 362.0; Found:
362.1. Anal. Calc.: C, 50.46; H, 3.50; N, 2.70. Found:
C, 49.88; H, 3.52; N, 2.67.
1
1JPt–P = 1717 Hz). H NMR (298 K, CDCl3): 8,46 (d,
3.2. Synthesis of [ Pt(dppp)(4-ethynylpyridine)2]-
(OTf)2 (2)
JH–H = 6.1 Hz, 4H, Ha–pyr), 7.45–7.26 (m, 20H, Ph),
7.22 (d, 4H, Hb–pyr), 7.10 (m, 4H, PtC6H2,oH2,m), 6.69
(d, JH–H = 7.7 Hz, 4H, PtC6H2,oH2,m), 2.61 (s, br, 4H,
P–CH2), 1.88 (m, 2H, PCH2CH2). FAB(+) m/z;
[M + H+]: Calc.: 964.1; Found: 964.2. Anal. Calc.: C,
58.82; H, 4.25; N, 2.59. Found: C, 58.87; H, 4.29; N,
2.62.
Details of synthesis of 1 also apply to 2. IR (KBr,
cmꢂ1): 3230 m, m(C–H), 2109 m, m(C„C); 1260 vs,
1159 m, 1100 m, 1030 vs, (OTfꢂ). 31P{1H} NMR (298
K, THF, inset acetone-d6 with 1% POMe3): ꢂ16.1 (s,
1
1JPt–P = 3064 Hz). H NMR (298 K, acetone-d6): 9.01
(d, JH–H = 6.4 Hz, 4H, Ha–pyr), 7.81–7.31 (m, 20H, Ph),
7.07 (d, 4H, Hb–pyr), 4.33 (s, 2H, C„CH), 3.42 (s, br,
4H, P–CH2), 2.17 (m, 2H, PCH2CH2). ES(+) m/z;
[M2+]: Calc: 406.7; Found: 406.2. Anal. Calc.: C, 46.44;
H, 3.24; N, 2.52. Found: C, 46.53; H, 3.51; N, 2.29.
3.5. Synthesis of [{Pt(l-4-(4-pyridylethynyl)phenyl)2-
(dppp)}2{Pd(dppf)}2](OTf)4 (5)
A dichloromethane (1 ml) solution of [Pd(H2O)2-
(dppf)](OTf)2 (12 mg, 0.01 mmol) was added dropwise

1618
M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
Table 2
Crystal data and details of the structural determination of 4
to a dichloromethane (2 ml) solution of [Pt(4-(4-pyridyle-
thynyl)phenyl)2(dppp)] (4) (10 mg, 0.01 mmol). After 1 h
of stirring at room temperature, the resulting mixture
turned orange. The solution was concentrated to 1 ml
under vacuum and the addition of diethylether (5 ml)
caused the precipitation of the product in 90% yield. IR
(KBr, cmꢂ1): 2209 s, 2150 w, m(C„C); 1258 vs, 1157 m,
1101 m, 1029 vs, (OTfꢂ). 31P{1H} NMR (298 K, CH2Cl2,
inset acetone-d6 with 1% POMe3): 31.1 (s, Pd–PPh2),
Empirical formula
Formula weight
Temperature (K)
C57H52N2OP2Pt
1038.04
293(2)
˚
Wavelength (A)
0.71073
Monoclinic
Cm
Crystal system
Space group
Unit cell dimensions
˚
a (A)
11.3140(12)
25.359(3)
˚
b (A)
1
1
ꢂ3.4 (s, JPt–P = 1719 Hz, Pt–P Ph2). H NMR (298K,
CDCl3): 8.55 (m, 8H, Ha–pyr), 7.80–6.72 (m, 96H, Ph +
PtC6H2,oH2,m + Hb–pyr), 6.47 (m, 8H, PtC6H2,oH2,m),
4.73 (s, 4H, Ha–ferr), 4.58 (s, 4H, Hb–ferr), 2.57 (s, br,
8H, P–CH2–), 1.79 (m, 4H, P–CH2–CH2–). ES(+) m/z;
[[Pt(4-(4-pyridylethynyl)phenyl)2(dppp)] + H+]: Calc.:
964.1; Found: 962.3; [(M ꢂ 4OTfꢂ)4+]: Calc.: 811.9;
Found: 811.0. Anal. Calc.: C, 29.37; H, 2.03; N, 0.73.
Found: C, 29.40; H, 2.07; N, 0.71.
˚
c (A)
9.7065(11)
90
a (ꢁ)
b (ꢁ)
c (ꢁ)
121.99(4)
90
2362.0(5)
3
˚
V (A )
Z
2
1.460
Dcalc (mg/m3)
Absorption coefficient (mmꢂ1
F(000)
)
3.080
1048
Crystal size (mm3)
0.01 · 0.07 · 0.48
2.27–28.30ꢁ
Theta range for data collection (ꢁ)
Index ranges
ꢂ15 6 h 6 13, ꢂ23 6 k 6 33,
3.6. X-ray structure determination of 4
ꢂ12 6 l 6 12
Reflections collected/unique
Refinement method
7502/4354 [R(int) = 0.0441]
Full-matrix least-squares on F2
4354/2/299
A prismatic crystal (0.01 · 0.07 · 0.48 mm) was se-
lected and mounted on a Bruker SMART-CCD area
diffractometer with graphite monochromatised Mo Ka
radiation using u scan-technique. 7502 reflections were
measured in the range 2.27 6 H 6 28.30ꢁ, 4354 of which
were non-equivalent by symmetry (Rint(on I) = 0.044).
3926 reflections were taken as observed and the condi-
tion I > 2r(I) was used. Lorentz-polarisation occurred,
but no absorption corrections were made. Numerical de-
tails are shown in Table 2.
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r (I)]
R indices (all data)
0.964
R1 = 0.0415, wR2 = 0.0684
R1 = 0.0529, wR2 = 0.0733
1.005 and ꢂ0.798
ꢂ3
˚
Largest diff. peak and hole (e A
)
Acknowledgements
Financial support for this research was provided by
the DGICYT (Project BQU2003-01131) and by the
CIRIT (Project 2001SGR00054).
The structure was solved by Patterson synthesis,
using the SHELXS computer program [23], and refined
by full-matrix least-squares method with the SHELXL
computer program [24], using 4354 reflections. The
function minimised was RwiFo|2 ꢂ |Fc|2|2, where
w = rꢂ2(I), f, f0 and f00 were taken from the International
Tables of X-Ray Crystallography [25]. The chirality of
structure was defined from the Flack coefficient, which
was equal to 0.021(9) for the given results [26]. The posi-
tion of 22 H atoms was computed and refined using a
riding model with an isotropic temperature factor equal
to 1.2 times the equivalent of the linked C atom. The fi-
nal R(on F) factor was 0.042, wR(on |F|2) = 0.068 and
Goodness-of-fit = 0.964 for all observed reflections.
Number of refined parameters was 299. Max. shift/
esd = 0.001, Mean shift/esd = 0.000. Max. and min.
peaks in final difference synthesis were 0.605 and
References
[1] P.J. Stang, Chem. Eur. J. 4 (1998) 19.
[2] (a) S. Leininger, B. Olenyuk, P.J. Stang, Chem. Rev. 100 (2000)
853;
(b) G.F. Swiegers, T.J. Malafetse, Chem. Rev. 100 (2000) 3483;
(c) M. Fujita, Chem. Soc. Rev. 27 (1998) 417;
(d) B.J. Holliday, C.A. Mirkin, Angew. Chem., Int. Ed. Engl. 40
(2001) 2022;
(e) F.A. Cotton, C. Lin, C.A. Murillo, Acc. Chem. Res. 34 (2001)
759;
(f) J.A.R. Navarro, B. Lippert, Coord. Chem. Rev. 185 (1999) 653.
[3] (a) See, for example: M. Fujita, J. Yakazi, K. Ogura, J. Am.
Chem. Soc. 112 (1990) 5645;
(b) M. Fujita, J. Yakazi, K. Ogura, Tetrahedron Lett. 32 (1991)
5589;
ꢂ0.398 e Aꢂ3, respectively.
˚
Crystallographic data for the structural analysis were
deposited with the Cambridge Crystallographic Data
Centre, CCDC No. 255640 for compound 4. 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; deposit@ccdc.
cam.ac.uk or e-mail: http://www.ccdc.cam.ac.uk).
(c) P.J. Stang, D.H. Cao, S. Saito, A.M. Arif, J. Am. Chem. Soc.
117 (1995) 6273;
(d) M. Fujita, Y.J. Kwon, S. Washizu, K. Ogura, J. Am. Chem.
Soc. 116 (1994) 1151;
(e) M. Fujita, S. Nagao, M. Iida, K. Ogat, K. Ogura, J. Am.
Chem. Soc. 115 (1993) 1574;
(f) P.J. Stang, B. Olenyuk, Angew. Chem., Int. Ed. Engl. 35
(1996) 732;

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 1612–1619
1619
´
(g) J.M. Brown, J.J. Perez-Torrente, N.W. Alcock, Organomet-
allics 14 (1995) 1195;
(f) S.-S. Sun, A.S. Silva, I.M. Brinn, A.J. Lees, Inorg. Chem. 39
(2000) 1344.
(h) J. Manna, C.J. Kuehl, J.A. Whiteford, P.J. Stang, D.C.
Muddiman, S.A. Hofstadler, R.D. Smith, J. Am. Chem. Soc. 119
(1997) 11611;
[12] (a) M. Ohkita, T. Suzuki, K. Nakatani, T. Tsuji, J. Chem.
Commun. (2001) 1454;
(b) D.M. Ciurtin, N.G. Pschirer, M.D. Smith, U.H.F. Bunz, H.-
C. zur Loye, Chem. Mater. 13 (2001) 2743;
(c) L. Yang, K.-K. Cheung, A. Mayr, J. Organomet. Chem. 585
(1999) 26.
(i) Y. Zhang, S. Wang, G.D. Enright, S.R. Breeze, J. Am. Chem.
Soc. 120 (1998) 9398;
(j) K. Onitsuka, S. Yamamoto, S. Takahashi, Angew. Chem., Int.
Ed. Engl. 38 (1999) 174;
[13] (a) H.A. Brune, M. Wiege, T. Debaerdemaekre, Z. Naturforsch.
B 39 (1984) 359;
(b) T.J. Colacot, R.A. Teichman, R. Cea-Olivares, J.G. Alva-
´
(k) M. Ferrer, L. Rodrıguez, O. Rossell, J. Organomet. Chem.
681 (2003) 158;
´
rado-Rodrıguez, R.A. Toscano, W.J. Boyko, J. Organomet.
Chem. 557 (1998) 169;
(l) M. Ferrer, M. Mounir, O. Rossell, E. Ruiz, M.A. Maestro,
Inorg. Chem. 42 (2003) 5890;
(m) M. Janka, G.K. Anderson, N.P. Rath, Organometallics 23
(2004) 4382;
(c) T. Debaerdemaeker, R. Hohenadel, H.A. Brune, J. Organo-
met. Chem. 410 (1991) 265;
(n) K.-W. Chi, C. Addicott, A.M. Arif, N. Das, P.J. Stang, J.
Org. Chem. 68 (2003) 9798;
(d) T. Debaerdermaeker, K. Berhalter, C. Weisemann, H.A.
Brune, Acta Crystallogr., Sect. C: Cryst. Struct. Commun. 43
(1987) 1253;
(o) W. Kaim, B. Schwederski, A. Dogan, J. Fiedler, C.J. Kuehl,
P.J. Stang, Inorg. Chem. 41 (2002) 4025.
[4] (a) P.J. Stang, J.A. Whiteford, Organometallics 13 (1994)
3776;
(e) B.L. Edelbach, D.A. Vicic, R.J. Lachicotte, W.D. Jones,
Organometallics 17 (1998) 4784;
(f) T. Debaerdemaeker, H.P. Klein, M. Wiege, H.A. Brune, Z.
Naturforsch. B 36 (1981) 958.
(b) J.A. Whiteford, C.V. Lu, P.J. Stang, J. Am. Chem. Soc. 119
(1997) 2524;
(c) C. Muller, J.A. Whiteford, P.J. Stang, J. Am. Chem. Soc. 120
¨
[14] J. Vicente, M.T. Chicote, Coord. Chem. Rev. (1999) 1143, and
references therein.
´
[15] M. Ferrer, L. Rodrıguez, O. Rossell, F. Pina, J.C. Lima, M. Font
(1998) 9827.
[5] P.J. Stang, N.E. Persky, Chem. Commun. (1997) 77.
[6] S.-S. Sun, A.J. Lees, Inorg. Chem. 40 (2001) 3154.
[7] (a) R.V. Slone, D.I. Yoon, R.M. Calhoun, J.T. Hupp, J. Am.
Chem. Soc. 117 (1995) 11813;
Bardia, X. Solans, J. Organomet. Chem. 678 (2003) 82.
[16] M.I. Bruce, B.C. Hall, B.W. Skelton, M.E. Smith, A.H. White, J.
Chem. Soc., Dalton Trans. (2002) 995.
[17] T.G. Appleton, M.A. Bennett, I.B. Tomkins, J. Chem. Soc.,
Dalton Trans. (1976) 439.
(b) S.-S. Sun, J.A. Anspach, A.J. Lees, Inorg. Chem. 41 (2002)
1862.
[18] P.J. Stang, D.H. Cao, J. Am. Chem. Soc. 116 (1994) 4981.
[19] P.J. Stang, B. Olenyuk, J. Fan, A.M. Arif, Organometallics 15
(1996) 904.
[8] P. de Wolf, S.L. Health, J.A. Thomas, Chem. Commun. (2002)
2540.
[9] A. Mayr, J. Guo, Inorg. Chem. 38 (1999) 921.
[10] J.K. Bera, B.W. Smucker, R.A. Walton, K.R. Dunbar, Chem.
Commun. (2001) 2562.
[20] L.D. Ciana, A. Haim, J. Heterocyclic Chem. 21 (1984) 607.
[21] S. Takahashi, Y. Kuroyama, K. Sonogashira, N. Hagihara,
Synthesis (1980) 627 (We used [Pd(PPh3)4] as a catalyst instead of
[PdCl2(PPh3)2]).
[11] (a) See, for example, E. Iengo, B. Milani, E. Zangrando, S.
Geremia, E. Alessio, Angew. Chem., Int. Ed. Engl. 39 (2000)
1096;
[22] I.-Y. Wu, J.T. Lin, J. Luo, S.-S. Sun, C.-S. Li, K.-J. Lin, C. Tsai,
C.-C. Hsu, J.-L. Lin, Organometallics 16 (1997) 2038.
[23] G.M. Sheldrick, SHELXS-97, A Program for Solving Crystal
Structures, University of Go¨ttingen, Germany, 1997.
[24] G.M. Sheldrick, SHELXS-97, A Program for Crystal Structure
Refinement, University of Go¨ttingen, Germany, 1997.
[25] International Tables of X-ray Crystallography, vol. IV, Kynoch,
Birmingham, 1974, pp. 99–100 and 149.
(b) C.-F. Wang, E.-Q. Gao, Z. He, C.-H. Yan, Chem. Commun.
(2004) 720;
´
(c) L. Falvello, M. Tomas, Chem. Commun. (1999) 273;
(d) D. Guo, C.-y. Duan, F. Lu, Y. Hasegawa, Q.-J. Meng, S.
Yanagida, Chem. Commun. (2004) 1486;
(e) J. Fornie´s, J. Go´mez, E. Lalinde, M.T. Moreno, Chem. Eur. J.
10 (2004) 888;
[26] H.D. Flack, Acta Crystallogr., Sect. A 39 (1983) 876.