New rhodium(I) complexes with hemilabile amphiphilic phosphanes

Article abstract of DOI:10.1002/ejic.200300099

A series of Rh^I complexes was prepared and characterised with the following hemilabile amphiphilic phosphanes: R-(C₆H ₄)-(OCH₂CH₂)_n-PPh₂ [1 (R = tert-octyl, n = 1), 2 (R = tert-o

Full text of DOI:10.1002/ejic.200300099

FULL PAPER
New Rhodium( ) Complexes with Hemilabile Amphiphilic Phosphanes
I
[a]
[a]
[b]
[b]
´
Esteve Valls, Joan Suades,* Rene Mathieu, and Noel Lugan
Keywords: Phosphanes / Rhodium / Hemilabile ligands / Amphiphiles
A series of RhI complexes was prepared and characterised
with the following hemilabile amphiphilic phosphanes:
R−(C6H4)−(OCH2CH2)n−PPh2 [1 (R = tert-octyl, n = 1), 2 (R =
been isolated and the cis-[Rh(1)2(CO)2]+ compound has been
detected. [Rh(1)2(CO)]+ was prepared by decarbonylation of
trans-[Rh(1)2(CO)2]+, and low-temperature NMR spectro-
scopic studies have shown the hemilabile character of 1 with
a very weak P−O interaction. The molecular structure of
trans-Rh(CO)(1)2Cl was determined by X-ray crystallo-
tert-octyl, n = 5), 3 (R = tert-octyl, n = 13), 4 (R = n-nonyl, n =
¯
¯
¯
1.4), 5 (R = n-nonyl, n = 5), 6 (R = n-nonyl, n = 11)]. The
¯
¯
reactions between 1−6 and [Rh(COD)(THF)2]+, and the sub-
sequent reaction with CO were studied by 31P NMR and IR graphy and shows that the conformation of the tert-octyl-
spectroscopy. The data are consistent with the formation of
P-coordinated and chelated (P,O) species for ligands 2−6, in
agreement with the hemilabile character of these ligands. In
phenoxyethyl chains is nearly identical to that previously re-
ported in the complex trans-PdCl2(1)2.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
the case of ligand 1, the complex trans-[Rh(1)2(CO)2]+ has Germany, 2003)
Introduction
tants. In subsequent papers, we have reported on the com-
plexing properties of the neutral ligands 1Ϫ6 (Scheme 1)
towards RuII,[8] PdII,[10] and hydridorhodium() com-
plexes.[11] Hemilabile properties were clearly observed with
the RuII complexes.[8] Here, we present a study of the reac-
tivity of the neutral ligands 1Ϫ6 (Scheme 1) towards RhI.
The preparation of new functionalised ligands is a central
strategy for improving certain properties in transition metal
complexes. Phosphanes are among the most versatile li-
gands, since they allow the introduction of very different
functionalities by means of the different groups bound to
the phosphorus atom. In this way, phosphane ligands have
become water-soluble,[1] asymmetric,[2] hemilabile[3] and,
more recently, amphiphilic.[4] The amphiphilic ligands con-
tain hydrophilic and hydrophobic groups in the same mol-
ecule, and their metal complexes may aggregate forming
supramolecular arrangements, such as micelles and ves-
icles.[5] Such micro-heterogeneous systems are attractive for
improving catalytic processes, especially those that present
phase-transfer limitations, such as those occurring under bi-
phasic conditions.[6] This approach has been utilised in the
study of a catalytic reaction accelerated by vesicle forma-
tion.[7]
In previous papers, we described the synthesis of neutral
amphiphilic phosphanes with hemilabile properties,[8] and
anionic water-soluble amphiphilic phosphanes.[9] Ligands
were prepared in a straightforward manner from polyethyl-
ene glycol monoalkyl ethers, which are common starting
compounds as they are used extensively as non-ionic surfac-
Scheme 1
Results and Discussion
1. Ligands
[a]
´
`
Departament de Quımica, Universitat Autonoma de Barcelona,
Edifici C, Campus UAB, 08193 Bellaterra, Spain
Fax: (internat.) ϩ34-93-5813101
Ligands 1Ϫ6 were synthesised from commercial non-
ionic Igepal surfactants.[12] In agreement with the nature
of these starting non-ionic surfactants, the ligands were ob-
tained as mixtures of compounds with the same structure
but with different ethoxylation grades (Scheme 1). The only
exception is 1, which was obtained as a single compound
E-mail: Joan.Suades@uab.es
[b]
Laboratoire de Chimie de Coordination du CNRS,
205 route de Narbonne, 31077 Toulouse Cedex 4, France
Fax: (internat.) ϩ33-5-61553003
E-mail: mathieu@lcc.toulouse.fr
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DOI: 10.1002/ejic.200300099
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3047

E. Valls, J. Suades, R. Mathieu, N. Lugan
FULL PAPER
because it crystallised from the reaction mixture as a ligand could have been replaced by oxygen atoms of the
white solid.
polyether chain,[15] as represented in Scheme 2.
2. Reactivity of Ligands 1؊6 towards
[Rh(COD)(THF)2][ClO4]
Two equivalents of the ligand (1Ϫ6) in THF were added
to a solution of [Rh(COD)(THF)2][ClO4] prepared by the
usual reaction between Rh(COD)(acac) and HClO4 in
THF. Complexation was evidenced by the change in the
colour of the solution, which became darker, and by the
31P{1H} NMR spectroscopic data. Although several at-
tempts were made, no solid compounds could be obtained.
Difficulties in the isolation of solid compounds were also
observed in previous complexation studies of ligands 1Ϫ6
with RuII [8] and PdII.[10]
Scheme 2
3. Reaction of [Rh(COD)(L)2]؉ Complexes with CO
a) Case where L ؍ Ligands 2؊6
After CO was bubbled into THF solutions of the RhI
complexes described above, the colour turned from orange
to yellow. After solvent evaporation, the reaction products
were studied by IR and 31P NMR spectroscopy, since, as in
the previous section, no solids could be obtained. The
31P{1H} NMR spectra show that the previously observed
signals are now absent and a new main signal at δ ϭ
22Ϫ25 ppm, with the characteristic shape of a doublet
(JRh-P ϭ 110Ϫ130 Hz) is observed for all the complexes
studied. The IR spectra in the νCO region display a strong
νCO band at around 1980 cmϪ1. The position of this band
is very similar to that reported for related complexes
with the [Rh(CO)(PʝO)(PO)]ϩ structure as trans-
[Rh(CO)(Ph2PCH2CH2OMe)2]ϩ (νCO ϭ 1982 cmϪ1).[13]
For these last complexes, equilibrium between the κ1 and
κ2 modes of bonding for the two ligands has been suggested
(Scheme 3).[13] The JRh-P coupling constant observed at
room temperature in the 31P{1H} NMR spectra for our
complexes is also consistent with this formulation.
The 31P{1H} NMR spectra of solutions obtained after
the reactions of 1Ϫ6 with [Rh(COD)(THF)2][ClO4] show
the complete absence of the corresponding free ligand, and
display several doublets with coupling constants in the
range 121 to 153 Hz. This result agrees with the formation
of RhϪP bonds for all the ligands studied. Significant dif-
ferences are also observed between the spectra for the dif-
ferent ligands. A comparison of the 31P NMR spectroscopic
data obtained from the resulting reaction mixtures
with published data reporting the reactivity of related
[13]
hemilabile
Ph2P(CH2CH2O)2CH3
phosphanes
Ph2PCH2CH2OCH3
and
[14]
is very helpful in the interpret-
ation of our results. The spectrum of the complex obtained
with ligand 1 only displays a doublet at δ ϭ 17.6 ppm
(1JPRh ϭ 144 Hz). This is in good agreement with the pres-
ence of a sole [Rh(COD)(PO)2]ϩ species (PO ϭ P-coordi-
nated etherϪphosphane ligand). The spectra of the com-
plexes obtained with ligands 2Ϫ6 also show a doublet with
similar characteristics at 17Ϫ18 ppm, however, other dou-
blets are also observed in the δ ϭ 28 ppm region. In these
spectra, as the polyether chain length increases (i.e. more
oxygen atoms are added), the signal that appears at
17Ϫ18 ppm is smaller. At the same time, the signals at
around δ ϭ 28 ppm become more significant. These results
agree with the simultaneous formation of the above-men-
tioned P-coordinated species [Rh(COD)(PO)2]ϩ (δ ϭ
17Ϫ18 ppm region), and the chelated (P,O) complexes
Scheme 3
b) Case where L ؍ Ligand 1
As in previously reported studies,[8,10] more detailed work
[Rh(COD)(PʝO)]ϩ (δ ϭ 28 ppm region)[14] (PʝO ϭ che- was performed with ligand 1 since it is the only compound
lated ligand). The absence of the signal in the δ ϭ 28 ppm that it is not a mixture of polyether ligands,[12] and there-
region in the spectrum with ligand 1 is consistent with the fore, the solid compounds can be expected to be isolated.
unfavourable bidentate coordination of this ligand, since it With this aim, the COD complex with the tetrafluoroborate
is hindered by electronic and steric effects of the aryl group anion was synthesised by reaction of the [Rh(COD)Cl]2
bonded to the oxygen atom.[10] Finally, some observations complex with two equivalents of AgBF4 and four equiva-
can be made from the spectra of the complexes with ligands lents of ligand 1 in THF. A solid complex was isolated by
4 and 6. The spectrum of the complex with ligand 4 shows subsequent reaction with CO, followed by crystallisation in
two doublets at δ ϭ 17.5 and 17.8 ppm that can be assigned diethyl ether. This complex displays an IR νCO band at 2040
to a mixture of [Rh(COD)(PO)2]ϩ complexes, since this li- cmϪ1, and a broad doublet in the 31P{1H} NMR spectrum
gand is a mixture that contains a molecule similar to 1 and at δ ϭ 21.0 ppm (J ϭ 104.8 Hz). These spectroscopic par-
another species with a longer polyether chain. In the spec- ameters are in accordance with published data for trans-
trum of the complex with ligand 6, other signals are also [Rh(CO)2L2]ϩ complexes with related hemilabile ether li-
[16]
observed at δ ϭ 32.4 and 39.5 ppm. These signals could be gands Cy2PCH2CH2OCH3
and Ph2PCH2CH2OPh.[17]
justified by the presence of species in which the labile COD Although other published data indicate that formation of
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Rhodium(I) Complexes with Hemilabile Amphiphilic Phosphanes
FULL PAPER
the trans-[Rh(PPh3)2(CO)2]ϩ is uncertain,[18] its existence
has been unequivocally demonstrated with the ether ligand
Ph2PCH2CH2OPh, using 31P NMR spectroscopy of 13CO
labelled complexes.[17] The low-temperature 31P{1H} NMR
spectrum of the dichloromethane solution of the trans-
[Rh(1)2(CO)2]ϩ complex shows that the broad doublet be-
comes sharp at a temperature lower than 233 K. A plausible
explanation of this could be the restricted rotation around
the phosphorusϪmetal bond at lower temperatures as a re-
sult of hydrophobic interactions between the two tert-octyl
chains. The two reported crystal structures of metallic com-
plexes with this ligand (see reference[10] and section 4 of
Results and Discussion) have shown that these hydrophobic
interactions could be related to the configuration of the
molecules in solid state. The IR spectrum of the mother
solution after crystallisation of the trans-[Rh(1)2(CO)2]ϩ
complex shows two signals at 2040 and 1990 cmϪ1, and
suggests the existence of the kinetically favoured cis-
[Rh(1)2(CO)2]ϩ complex in solution.[16]
The formation of the monocarbonyl complex trans-
[Rh(CO)(PʝO)(PO)]ϩ with ligands 2Ϫ6 and the dicarbonyl
complex trans-[Rh(1)2(CO)2]ϩ can be justified by the pro-
pensity of ligand 1 to avoid the P,O chelation because of
electronic and steric effects.[10] To force the coordination of
the oxygen atom in ligand 1, the synthesis of the monocar-
bonyl complex was undertaken by refluxing a dichloro-
methane solution of the trans-[Rh(1)2(CO)2]ϩ complex.
This reaction was monitored by IR spectroscopy, which
showed the quick formation of a new complex with a νCO
band at 1990 cmϪ1. The 31P{1H} NMR spectrum at room
temperature shows a broad doublet at δ ϭ 29.5 ppm (J ϭ
120.1 Hz). The low-temperature 31P{1H} NMR spectro-
scopic measurements (Figure 1) show the evolution of the
broad doublet to a broad band at 253 K and a very broad
band (22Ϫ37 ppm) at 233 K. At lower temperatures, a
sharp doublet is formed at δ ϭ 23.8 ppm (J ϭ 134.3 Hz)
and a broad doublet at δ ϭ 34.8 ppm (J ϭ 110 Hz) in a 1:1
ratio. These data are consistent with the existence of a
κ1(P)-coordinated ligand (doublet at δ ϭ 23.8 ppm) and a
κ2 (P,O)-coordinated ligand (doublet at δ ϭ 34.8 ppm). The
fact that the κ2 (P,O) resonance remains broad at this tem-
perature illustrates the previously mentioned unfavourable
κ2 (P,O) coordination mode for 1. Reported studies with
the Ph2PCH2CH2OPh ligand have shown the existence of
coordinated arene complexes, and the κ2 (P,O) coordination
of this ligand has been postulated in reaction intermedi-
ates.[17] The low-temperature 1H NMR spectra show the
splitting of the signal for the two methylene groups of 1 at
193 K. Furthermore, the arene protons of the phenoxy
groups show two sharp doublets at room temperature at
δ ϭ 6.63 and 7.16 ppm, which are assigned to the ortho-
and meta arene hydrogen atoms of the phenoxy group,
respectively. At low temperatures, the signal for the meta
hydrogen atom shows insignificant changes. In contrast, the
signal for the ortho-hydrogen atom shows a broad band at
213 K, which splits into two signals: a sharp band at δ ϭ
Figure 1. Low-temperature 31P{1H} NMR spectra of
[Rh(CO)(1)2][BF4]
groups that shows the existence of two different
CH2CH2O(C6H4)C8H17 fragments and the splitting of the
signal for the ortho hydrogen atoms of the phenoxy groups
Ϫ are consistent with the co-existence of a κ1 (P) and a κ2
(P,O)-coordinated ligand and corroborate the 31P{1H}
NMR spectroscopic data. It should be emphasised that a
η6-coordination of the arene group is not favourable for
electronic reasons and a η2-coordination of the arene is not
1
supported by the H NMR spectroscopic data.
Finally, the attracting properties of this ligand should be
noted because it can be considered as an hemilabile (P,O)
ligand with a very weak, but possible, interaction between
the oxygen atom and the metal atom. This observation is
supported by our previous studies with RuII and PdII com-
plexes. Those studies show the prevailing trend of this li-
gand to coordinate only by means of the phosphorus
atom.[8,10] Finally, further support is available from the pub-
lished reports on the ligand Ph2PCH2CH2OPh, where the
P,O coordination was only postulated in the reaction inter-
mediates.[17]
4. Synthesis and X-ray Structure of trans-[Rh(CO)(1)2Cl]
As it was not possible to get single crystals of the cationic
6.38 ppm and a broad signal at δ ϭ 6.65 ppm. All these complexes of ligand 1, another attempt was made with neu-
observations Ϫ the splitting of the signal for the methylene tral chloro rhodium complexes. The reaction of
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E. Valls, J. Suades, R. Mathieu, N. Lugan
FULL PAPER
Scheme 4
[Rh(COD)(µ-Cl)]2 with four equivalents of ligand 1 leads (Figure 3).[10] Indeed, on comparing both figures, the great
to a mixture of two species, according to the 31P{1H} NMR similarity between the conformations of the two tert-octyl-
spectrum of the reaction medium (Scheme 4). The first is phenoxyethyl chains in both complexes can be seen. In both
observed as a doublet at δ ϭ 28.2 ppm (1JPRh ϭ 150 Hz) complexes, the phenyl groups bonded to the phosphorus
and is assigned to the species [Rh(COD)(1)Cl]. The second atoms are nearly eclipsed, and the values of the
complex displays a set of signals consisting of a doublet of C2ϪP1ϪP2ϪC4 torsion angle in both complexes are very
2
doublets at δ ϭ 22.3 ppm (1JPRh ϭ 137 Hz; JP,P ϭ 39 Hz) similar {trans-[Rh(CO)(1)2Cl] ϭ 22(1)°; trans-[PdCl2(1)2] ϭ
and a doublet of triplets centred at δ ϭ 37.3 ppm (1JPRh
ϭ
24.0(2)°}. This implies that the two tert-octylphenoxyethyl
2
187 Hz; JP,P ϭ 39 Hz), and is assigned to the [Rh(1)3Cl] chains are close to each other, an arrangement that could
species. After bubbling CO into the previous reaction mix- be explained by the tendency of the more hydrophobic parts
ture, only one doublet at δ ϭ 21.3 ppm (1JPRh ϭ 124 Hz) is of the molecule to be close together. The analysis of the
observed. This signal and the presence of an IR band at structure of the [PdCl2(1)2] complex led us to consider,
1975 cmϪ1 are in good agreement with the formation of a jointly with the proposed hydrophobic interactions, that
trans-[Rh(CO)(1)2Cl] species. Single crystals of this complex other factors should also be taken into account. Thus, hy-
were obtained by crystallisation from an acetone/methanol drogen bonds between the Cl atom and the hydrogen atoms
solution, and the structure of complex was determined by of the methylene groups bonded to the oxygen atom, or
X-ray methods. A perspective view of the molecule with the between one oxygen atom and one phenyl group were con-
labelling scheme is shown in Figure 2. The rhodium atom sidered.[10] The noteworthy similarity between the confor-
displays a square-planar geometry with phosphane ligands mation of the hydrophobic groups in the structures of these
in the trans positions, confirming previous assignment from metal complexes with the two different metal fragments,
NMR spectroscopic data. Bond lengths and angles around PdCl2 and Rh(CO)Cl, suggests that the interaction between
the metal centre are similar to other trans-[Rh(CO)L2Cl] the tert-octylphenoxyethyl chains can play a central role in
complexes with monodentate phosphane ligands.[19] Note, the conformation of these complexes. It should be empha-
however, that the most interesting information is attained sised that in the homologous trans-[PdCl2L2][20] and trans-
on comparing the structure of trans-[Rh(CO)(1)2Cl] (Fig- [Rh(CO)ClL2][19b] complexes with the ligand PPh2Me,
ure 2) with that of the previously reported trans-[PdCl2(1)2] which cannot lead to significant hydrophobic interactions
between the methyl groups, the conformation of the two
complexes is different (Figure 4). Thus, the phenyl groups
Figure 2. ORTEP diagram of trans-[Rh(CO)(1)2Cl] showing the
atom numbering scheme. The phenyl rings bonded to phosphorus
have been omitted
Figure 3. View of the molecular structure of trans-[PdCl2(1)2]. The
phenyl rings bonded to phosphorus have been omitted
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Rhodium(I) Complexes with Hemilabile Amphiphilic Phosphanes
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Figure 4. Molecular structures of trans-[Rh(CO)(PPh2Me)2Cl][19b] (left) and trans-[PdCl2(PPh2Me)2][10] (right) showing the different con-
formations of the coordinated phosphane ligands
Reactivity of 1 toward [Rh(COD)(THF)2][BF4] and CO: Synthesis
of trans-[Rh(CO)2(1)2][BF4]: [Rh(COD)(µ-Cl)]2 (100 mg, 0.2 mmol)
was dissolved in 10 mL of THF and AgBF4 (80 mg, 0.41 mmol)
was added to the solution. The solution was stirred for 1 h. Precipi-
tated AgCl was eliminated by filtration through a small pad of
Celite. 1 (340 mg, 0.81 mmol) was added to the resulting yellow
solution and the solution was stirred for 1 h. CO was bubbled into
the solution for 1 h and during this time the solution lightened.
THF was then evaporated under vacuum and the residue was dis-
solved in 5 mL of CH2Cl2. 15 mL of diethyl ether was added to this
solution and the resulting mixture was cooled to Ϫ20 °C. 250 mg of
trans-[Rh(CO)2(1)2][BF4] was isolated as a white powder (57%
yield). IR (νCO): 2041 cmϪ1 (CH2Cl2 solution); 31P{1H} NMR
(CDCl3): (293 K) 20.9 (bd, J ϭ 104.8 Hz); (233 K) 20.1 ppm, (d,
J ϭ 107.1 Hz). (1H) NMR (CD2Cl2): (293 K) 0.66 (s, 9 H), 1.31 (s,
6 H), 1.69 (s, 2 H), 3.16 (m, 2 H), 4.27 (m, 2 H), 6.57 (d, J ϭ
8.7 Hz, 2 H), 7.21 (d, J ϭ 8.7 Hz, 2 H), 7.44Ϫ7.65 ppm (m, 10 H).
C58H70BF4O4P2Rh (1082.8): calcd. C 64.3, H 6.5; found C 63.9,
H 7.0.
are nearly eclipsed in the rhodium complex and the methyl
groups are closer, whereas in the palladium complex the
two methyl groups are located as far apart as possible.
Experimental Section
General Remarks: All reactions were performed under nitrogen by
standard Schlenk tube techniques. The NMR spectra were re-
`
`
corded by the Servei de Ressonancia Magnetica Nuclear de la Univ-
`
ersitat Autonoma de Barcelona on a Bruker AC250 instrument. All
chemical shift values are given in ppm and are referenced with re-
1
spect to residual protons in the deuterated solvents for H spectra,
to solvent signals for 13C spectra and to external phosphoric acid
for 31P{1H} spectra. Coupling constants, in parentheses, are ex-
pressed in Hz. Infrared spectra were recorded on a PerkinϪElmer
FT-2000.
Compounds 1Ϫ6 were prepared by published procedures.[8b]
`
´
Microanalyses were performed in the Servei d’Analisi Quımica de
Synthesis of [Rh(CO)(1)2][BF4]: trans-[Rh(CO)2(1)2][BF4] (250 mg)
was dissolved in 15 mL of CH2Cl2 and the solution was refluxed
for 5 h. The solution was evaporated to dryness and the residue
was crystallised in a CH2Cl2/hexane mixture at Ϫ20 °C. 200 mg of
[Rh(CO)(1)2][BF4] was isolated (82%). IR (νCO): 1990 cmϪ1
(CH2Cl2 solution); 31P{1H} NMR (CD2Cl2): (293 K) 29.5 (bd, J ϭ
120.1 Hz); (193 K) 23.8, (d, J ϭ 134.3 Hz), 34.8 ppm, (bd, J ϭ
110 Hz). (1H) NMR (CD2Cl2): (293 K) 0.69 (s, 9 H), 1.31 (s, 6 H),
1.69 (s, 2 H), 2.83 (m, 2 H), 4.21 (m, 2 H), 6.63 (d, J ϭ 8.7 Hz, 2
H), 7.16 (d, J ϭ 8.7 Hz, 2 H), 7.47Ϫ7.70 ppm (m, 10 H). (193 K)
0.56 (bs, 18 H), 1.23 (bs, 12 H), 1.62 (s, 4 H), 2.57 (b, 2 H), 3.01
(b, 2 H), 3.92 (b, 2 H), 4.22 (m, 2 H), 6.38 (2 H), 6.66 (2 H), 7.05
(b, 4 H), 7.41Ϫ7.63 ppm (m, 20 H). C57H70BF4O3P2Rh (1054.8):
calcd. C 64.9, H 6.7; found C, 65.0, H 6.5.
`
la Universitat Autonoma de Barcelona.
Reactivity of 1؊6 toward [Rh(COD)(THF)2]؉: In a representative
procedure 70% HClO4 (0.16 mmol) was added to a yellow solution
of [Rh(COD)(acac)] (0.16 mmol) in 10 mL of THF. The solution
turned slightly orange. After stirring for several minutes, the corre-
sponding phosphane ligand (0.32 mmol) in 5 mL of THF was ad-
ded. The orange colour became more intense. The reaction mixture
was stirred for over one hour at room temperature. The 31P{1H}
NMR spectrum of the reaction mixture was recorded by adding
[D6]acetone to the THF solutions. 1: 17.6 d (J ϭ 144 Hz). 2: 17.6
(d, J ϭ 142 Hz), 23.8 (d, J ϭ 122 Hz), 28.7 (d, J ϭ 139 Hz). 3: 17.0
(b), 28.8 (d, J ϭ 139 Hz). 4: 17.5 (d, J ϭ 150 Hz), 17.8 (d, J ϭ
142 Hz). 5: 17.7 (d, J ϭ 142 Hz), 26.8 (b). 6: 17.6 (d, J ϭ 144 Hz),
28.5 (d, J ϭ 153 Hz), 32.4 (d, J ϭ 121 Hz), 39.5 ppm (d, J ϭ
130 Hz).
Synthesis of trans-Rh(CO)(1)2Cl: Ligand
1 (0.27 mmol) and
[Rh(COD)(µ-Cl)]2 (0.06 mmol) were dissolved in 25 mL of CH2Cl2.
The yellow reaction mixture was stirred for one hour. The 31P{1H}
NMR spectrum of this reaction mixture was recorded by adding
[D6]acetone: 22.3 (dd, 1JRhP ϭ 137, 2JP,P ϭ 39 Hz); 28.2 (d, 1JRhP ϭ
Reactivity of 2؊6 toward [Rh(COD)(THF)2]؉ and CO: When CO
was bubbled into the previous reaction mixture its colour rapidly
turned pale yellow. Bubbling was maintained for one hour after
which the reaction solvents were evaporated to dryness. The
31P{1H} NMR and IR spectra of the resulting oily products were
recorded by adding [D6]acetone to the dichloromethane solutions.
31P{1H} NMR spectroscopic data: 2: 22.0 (d, J ϭ 130 Hz), 23.6 (d,
J ϭ 127 Hz). 3: 21.8 (d, J ϭ 124 Hz). 4: 25.4 (broad d, J ഠ 110 Hz).
1
2
150 Hz); 37.3 ppm (dt, JRhP ϭ 187, JP,P ϭ 39 Hz).
CO was bubbled into the reaction mixture for one hour and during
this time the colour changed to pale yellow. The solution was eva-
porated to dryness and the residue was crystallised in a acetone/
methanol mixture at Ϫ20 °C. 75 mg of trans-[Rh(CO)(1)2Cl] was
5: 23.8 (d, J ϭ 110 Hz), 30.7 (d, J ϭ 113 Hz). 6: 23.2 (d, J ϭ isolated (62%). IR (νCO): 1975 cmϪ1 (CH2Cl2 solution). 31P{1H}
113 Hz), 32.5 ppm (d, J ϭ 118 Hz). IR data (νCO, CH2Cl2 solu-
NMR (CD2Cl2): 21.3 ppm d (1JRhP ϭ 124 Hz). C57H70O3ClP2Rh:
tion): 2, 1980; 3, 1972; 4, 1980; 5, 1979; 6, 1983 cmϪ1
.
calcd. C 68.2, H 7.0; found C, 67.5, H 7.4.
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E. Valls, J. Suades, R. Mathieu, N. Lugan
FULL PAPER
[1]
X-ray Crystallographic Study: Data were collected on an
EnrafϪNonius CAD4 diffractometer at room temperature. Full
crystallographic data for trans-[Rh(CO)(1)2Cl] are gathered in
Table 1. All calculations were performed on a PC-compatible com-
puter using the WinGX system.[21] The structures were solved by
direct methods, using the SIR92 program,[22] which revealed in each
instance the position of most of the non-hydrogen atoms. All re-
maining non-hydrogen atoms were located by the usual combi-
nation of full-matrix least-squares refinement and difference elec-
tron density syntheses using the SHELXS-97 program.[23] One tert-
octyl group showed structural disorder and it was split; final s.o.f.
was 0.5/0.5. The phenyl rings have been refined as rigid groups (D6h
B. Cornils, W. A. Herrmann (Eds.), Aqueous-Phase Organomet-
allic Catalysis, Wiley-VCH, Weinheim, 1998, chapter 3.2.
[2] [2a]
H. B. Kagan, in: Asymmetric Synthesis (Ed.: J. D. Mor-
rison), vol. 5, Academic Press, Orlando, 1985, chapter 1. [2b] H.
Brunner, W. Zettlmeier, Handbook of Enantioselective Catalysis
with Transition Metal Compounds, vol. II, VCH, Weinheim,
[2c]
1993.
J. Holz, M. Quirmbach, A. Börner, Synthesis 1997,
9, 983.
[3]
[3a] E. Lindner, S. Pautz, M. Haustein, Coord. Chem. Rev. 1996,
155, 145. [3b] H. Yang, M. Alvarez-Gressier, N. Lugan, R. Ma-
thieu, Organometallics 1997, 16, 1401. [3c] E. Lindner, S. Pautz,
R. Fawzi, M. Steimann, J. Organomet. Chem. 1998, 555, 247.
[3d]
I. Le Gall, P. Laurent, E. Soulier, J. Salaün, H. Abbayes, J.
Organomet Chem. 1998, 567, 13.
Heller, W. Baumann, A. Spannenberg, R. Kempe, J. Holz, A.
Börner, Eur. J. Inorg. Chem. 1998, 9, 1291.
A. Weinberger, C. A. Mirkin, in: Progress in Inorganic Chemis-
[3e]
˚
˚
S. Borns, R. Kadyrov, D.
symmetry; CϪC ϭ 1.39 A; CϪH ϭ 0.93 A). Atomic scattering
factors were taken from the usual tabulations.[24] Anomalous dis-
persion terms for Rh, P, and Cl were included in Fc.[25] All non-
hydrogen atoms were allowed to vibrate anisotropically. All the hy-
[3f]
C. S. Slone, D.
try (Ed.: K. D, Karlin), Vol. 48, John Wiley & Sons, New York,
drogen atoms were set in idealised positions (R3CH, CϪH ϭ 0.96
[3g]
1999, p. 233.
J. L. Ruiz, T. Flor, J. C. Bayon, Inorg. Chem.
2
˚
˚
˚
A; R2CH2 ϭ 0.97 A; C(sp )ϪH ϭ 0.93 A; Uiso 1.2 times greater
than the Ueq of the carbon atom to which the hydrogen atom is
attached) and held fixed during refinements. Final atomic coordi-
nates for all atoms, anisotropic thermal parameters, lists of struc-
ture factor amplitude for compounds for the X-ray study are avail-
able from the authors upon request.
[3h]
Commun. 1999, 2, 484.
H. Werner, J. Bank, P. Steinert, W.
[3i]
Wolfsberger, Z. Anorg. Allg. Chem. 1999, 625, 2178.
M.
Nandi, J. Jin, T. V. RajanBabu, J. Am. Chem. Soc. 1999, 121,
9899.
[4]
G. Papadogiannakis, R. A. Sheldon, in ref.[1] chapter 3.2.4.
[5] [5a]
J. H. Van Esch, A. L. H. Stols, R. J. M. Nolte, J. Chem.
Soc., Chem. Commun. 1990, 1658. [5b] G. Ghirlanda, P. Scrimin,
P. Tecilla, A. Toffoletti, Langmuir 1998, 14, 1646. [5c] F. Hampl,
F. Liska, F. Mancin, P. Tecilla, U. Tonellato, Langmuir 1999,
Table 1. Crystal data and structure refinement for trans-
[Rh(CO)(1)2Cl]
[5d]
15, 405.
R. Resendes, J. Massey, H. Dorn, M. A. Winnik,
I. A. Manners, Macromolecules 2000, 33, 8.
[6] [6a]
B. E. Hanson, H. Ding, C. W. Kohlpaintner, Catalysis To-
Empirical formula
Molecular mass
Temperature
C57H70ClO3P2Rh
1003.43
day 1998, 421. [6b] G. Oehme, I. Grassert, S. Ziegler, R. Meisel,
[6c]
H. Fuhrman, Catalysis Today 1998, 42, 459.
R. Selke, J.
293(2) K
Holz, A. Riepe, A. Börner, Chem. Eur. J. 1998, 4, 769.
M. S. Goedheijt, B. H. Hanson, J. N. H. Reek, P. C. J. Kamer,
P. W. N. M. van Leeuwen, J. Am. Chem. Soc. 2000, 122, 1650.
˚
Wavelength
0.71073 A
[7]
Crystal system
Space group
Unit cell dimensions
triclinic
P1 (#2)
¯
[8] [8a]
E. Valls, J. Suades, B. Donadieu, R. Mathieu, Chem. Com-
˚
a ϭ 16.2300(10) A, α ϭ 101.98(2)°
mun. 1996, 771. [8b] E. Valls, J. Suades, R. Mathieu, Organomet-
allics 1999, 18, 5475.
˚
b ϭ 17.057(2) A, β ϭ 96.83(2)°
˚
c ϭ 10.0310(10) A, γ ϭ 77.830(10)°
[9]
E. Valls, A. Solsona, J. Suades, R. Mathieu, F. Comelles, C.
3
˚
Volume
Z
Absorption coefficient
F(000)
2647.2(4) A
1.259 Mg/m3
0.475 mmϪ1
1056
´
Lopez-Iglesias, Organometallics 2002, 21, 2473.
[10]
[11]
[12]
E. Valls, J. Suades, R. Mathieu, J. F. Piniella, A. Alvarez-Lar-
ena, J. Organomet. Chem. 2001, 626, 139.
A. Solsona, J. Suades, R. Mathieu, J. Organomet. Chem. 2003,
669, 172.
These products are ethoxylated alkylphenols with different eth-
oxylation grades.
E. Lindner, H. Norz, Chem. Ber. 1990, 123, 459.
V. V. S. Reddy, A. Varshney, G. M. Gray, J. Organomet. Chem.
1990, 391, 259.
E. Lindner, Q. Wang, H. A. Mayer, A. Bader, J. Organomet.
Chem. 1993, 458, 229.
E. Lindner, Q. Wang, H. A. Mayer, R. Fawzi, M. Steimann,
Organometallics 1993, 12, 1865.
E. T. Singewald, X. Shi, C. A. Mirkin, S. J. Schofer, C. L. Stern,
Organometallics 1996, 15, 3062.
Theta range for data
collection
Index ranges
1.24 to 21.98°
0ՅhՅ17, Ϫ17ՅkՅ17, Ϫ10ՅlՅ10
Independent reflections
Completeness to theta ϭ
21.98°
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I Ͼ 2σ(I)]
6462
99.8%
[13]
[14]
Full-matrix least-squares on F2
6462/11/544
1.054
[15]
[16]
[17]
[18]
R1 ϭ 0.0420, wR2 ϭ 0.1064
R. Schrock, J. A. Osborn, J. Am. Chem. Soc. 1971, 93, 2397.
CCDC-203524 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge at
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
Crystallographic Data Centre, 12, Union Road, Cambridge
CB2 1EZ, UK; fax: (internat.) ϩ44-1223-336-033; E-mail:
deposit@ccdc.cam.ac.uk].
[19] [19a] D. C. Smith Junior, E. D. Stevens, S. P. Nolan, Inorg. Chem.
[19b]
1999, 38, 5277.
F. Dahan, R. Choukroun, Acta Crys-
tallogr., Sect. C 1985, 41, 704.
[20]
I. Y. Guzman-Jimenez, K. H. Whitmire, Acta Crystallogr.,
Sect. C 1999, 55, 9900028.
L. J. Farrugia, J. Appl. Crystallogr. 1999, 32, 837.
A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, J.
Appl. Crystallogr. 1993, 26, 343.
G. M. Sheldrick, SHELXS-97, SHELXL-97, CIFTAB Ϫ Pro-
grams for Crystal Structure Analysis (Release 97Ϫ2), Institüt
für Anorganische Chemie der Universität, Tammanstrasse 4,
3400 Göttingen, Germany, 1998.
[21]
[22]
[23]
Acknowledgments
´
We thank the DGICYT (programa de Promocion General del
[24] [24a]
Conocimiento) for financial support.
D. T. Cromer, J. T. Waber, International Tables for X-ray
3052
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2003, 3047Ϫ3053

Rhodium(I) Complexes with Hemilabile Amphiphilic Phosphanes
FULL PAPER
D. T. Cromer and J. T. Waber, International Tables for X-ray
Crystallography, Kynoch Press: Birmingham, England, vol. 4,
1975, Table 2.3.1.
[25]
Crystallography; Kynoch Press: Birmingham, England, vol. 4,
[24b]
1974, Table 22B.
R. F. Stewart, E. R. Davidson, W. T.
[24c]
Simpson, J. Chem. Phys. 1965, 42, 3175.
T. Hahn (Ed.),
International Tables for Crystallography, Volume A, Kluwer
Academic Publishers, Dordrecht, The Netherlands, 1995.
Received February 19, 2003
Eur. J. Inorg. Chem. 2003, 3047Ϫ3053
www.eurjic.org
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3053