Heterobimetallic RePd complexes bridged by η1: η5-Ph2PC5H4 ligand. Synthesis, electronic and crystal structure of (CO)2(PR3) (η5-C5H4PPh2)Re-PdCl 2, R = Me and OMe

Article abstract of DOI:10.1039/b927265h

The new rhenium complexes (η⁵-C₅H ₄PPh₂)Re(CO)₂(PR₃) (R = Me (1) and OMe (2)) were prepared photochemically from (η⁵-C ₅H₄PPh₂)Re(CO)₃ in the presence of PMe₃ or P(OMe)₃. Further reaction of these ligands with PdCl₂(NCPh)₂ in chloroform, produces the heterobimetallic complexes (CO)₂(PMe₃)(η⁵-C ₅H₄PPh₂)Re-PdCl₂ (3) and (CO) ₂(P(OMe)₃)(η⁵-C₅H ₄PPh₂)Re-PdCl₂ (4). IR spectroscopy reveals that both complexes possess a Re-Pd interaction which was confirmed by X-ray crystallography (Re-Pd bond distance = 2.762 A in 3 and 2.774 A in 4). Relativistic functional density theory calculations have also been carried out in order to probe the bonding in these compounds.

Full text of DOI:10.1039/b927265h

View Article Online / Journal Homepage / Table of Contents for this issue
PAPER
www.rsc.org/dalton | Dalton Transactions
1
5
=
Heterobimetallic Re Pd complexes bridged by g :g -Ph2PC5H4 ligand.
Synthesis, electronic and crystal structure of
(CO)2(PR3)(g5-C5H4PPh2)Re–PdCl2, R = Me and OMe†
Diego Sierra,a A. Hugo Klahn,*a Rodrigo Ramirez-Tagle,b Ramiro Arratia-Perez,*b Fernando Godoy,c
Maria Teresa Garlandd and Mauricio Fuentealbab,d
Received 5th January 2010, Accepted 6th May 2010
First published as an Advance Article on the web 3rd June 2010
DOI: 10.1039/b927265h
5
The new rhenium complexes (h -C5H4PPh2)Re(CO)2(PR3) (R = Me (1) and OMe (2)) were prepared
5
photochemically from (h -C5H4PPh2)Re(CO)3 in the presence of PMe3 or P(OMe)3. Further reaction of
these ligands with PdCl2(NCPh)2 in chloroform, produces the heterobimetallic complexes
5
5
(CO)2(PMe3)(h -C5H4PPh2)Re–PdCl2 (3) and (CO)2(P(OMe)3)(h -C5H4PPh2)Re–PdCl2 (4). IR
spectroscopy reveals that both complexes possess a Re–Pd interaction which was confirmed by X-ray
˚
˚
crystallography (Re–Pd bond distance = 2.762 A in 3 and 2.774 A in 4). Relativistic functional density
theory calculations have also been carried out in order to probe the bonding in these compounds.
donor groups. Casey and Rheingold12 described for the first time
Introduction
the synthesis and characterization of manganese and rhenium
5
5
Diphenylphosphinocyclopentadienyl groups h -coordinated to
metal fragments have proven to be versatile unsymmetrical
mono- or bidentate ligands to form homo- and heterobimetallic
complexes.1–3 The most common complexes of this class include
those which have two metal centers held together through
a simple bridging (monodentate) ligand.4,5 A large number
complexes (CO)3(h -C5H4PR2)MoM(CO)4 (M = Re, Mn; R = Ph,
p-tolyl). Since then, a large number of homo- and heterobimetallic
complexes have been published. Some other examples are: MoI-
5
5
5
(CO)3[h -C5H4P(Ph)(h C5H4)](CO)3MoPd(PPh3)I,13
[h C5H4-
P(Ph)(Bu)](CO)3MoPd(PPh3)I,14
Me[m-(h -C5H2(PR2)]2ZrRh-
5
(CO)(L), R = Ph, iso-Pr, Cy; L = CO, PPh3,15 (CO)3(h -C5H2-
5
5
(Ph2)PPh2)MPd(PPh3)I, M = Mo, W,16 [m-(h -C5H4PPh2)M-
5
of bimetallic complexes containing ligands of the type (h -
(CO)2]2 (M = Cr, Mo, W),17 and (CO)3(h -C5H4PR2)MPd-
5
C5H4PPh2)MLn, M = Fe, Ti, Zr, Co, Mo, Rh, etc., with interesting
chemical, electrochemical and catalytic properties have been
prepared.1,2,6 Nevertheless, bimetallic complexes containing group
7 ligands remain relatively unexplored. As far as we are aware,
only a few examples of these types of complexes have been
reported. For instance, Rausch and co-workers7 reported the
(PPh3)I (M = Mo, W)18 [m-(h -C5H4PPh2)Rh(CO)]2
.
5
2+ 19
In this paper we would like to report the synthesis and
5
characterization of the new ligands based on rhenium (h -
C5H4PPh2)Re(CO)2(PR3) (R = Me and OMe) and their reac-
tions with PdCl2(NCPh)2 leading to the bimetallic complexes
5
5
homobimetallic complex [m-(h -C5H4PPh2)Mn(CO)2]2, whereas
(CO)2(PR3)(h -C5H4PPh2)RePdCl2 in which the palladium moiety
Gladysz and co-workers described the formation of Pd(II)8 and
Rh(I)9 adducts by using the related chelating diphosphine lig-
is chelated by the phosphine and rhenium atoms.
5
Results and discussion
1. Synthesis of the ligands (g5-C5H4PPh2)Re(CO)2(PR3) and their
ands (h -C5H4PPh2)Re(NO)(PPh3)((CH2)nPPh2) (n = 0, 1). Very
recently, we reported the coordination capability to Pd(II), Au(I)
5
and Cu(I) of the ligand (h -C5H4PPh2)Re(CO)3 supported by
palladium complexes
crystallographic information.10
5
The ligands (h -C5H4PPh2)Re(CO)2(PR3) R = Me (1) and R =
With regard to bidentate ligands, most of the literature
reports deal with the anionic derivatives having diphenylphos-
phinocyclopentadienyl bound to the tricarbonyl moiety of group
OMe (2) were prepared following the same procedure described
for the preparation of Cp or Cp*Re(CO)2(PR3),20,21 (see Scheme 1)
that is, by UV-irradiation (l = 300 nm) of the tricarbonyl complex
5
6 transition metals, especially molybdenum and tungsten [(h -
5
C5H4PPh2)M(CO)3]-, (M = Mo, W).11 These anions can be viewed
(h -C5H4PPh2)Re(CO)3 in the presence of the corresponding
phosphorous ligand.
as difunctional chelated ligands, with phosphine and metal anion
aInstituto de Qu´ımica, Pontificia Universidad Cato´lica de Valpara´ıso,
Valpara´ıso, Chile. E-mail: hklahn@ucv.cl; Tel: (56)-(32)-2274922
bUniversidad Andres Bello, Departamento de Ciencias Qu´ımicas, Santiago,
Chile
cDepartamento de Qu´ımica de los Materiales Facultad de Qu´ımica y
Biolog´ıa, Universidad de Santiago de Chile, Santiago, Chile
dCIMAT, Facultad de Ciencias F´ısicas y Matema´ticas, Universidad de Chile,
Santiago, Chile
† CCDC reference numbers 756945 and 756946. For crystallographic data
in CIF or other electronic format see DOI: 10.1039/b927265h
Scheme 1
After work up the compounds were isolated as white solids in
about 51% yield. It is important to note that we have no evidence
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 6295–6301 | 6295
©

View Article Online
5
for the formation of a dimeric species [m-(h -C5H4PPh2)Re(CO)2]2,
Drawings of the molecular structures of complexes 3 and 4 with
their respective labelling scheme are shown in Figs. 1 and 2, the
hydrogen atoms and the solvent molecules have been omitted for
clarity.
which could be formed in the photochemical reactions, as
was previously observed by Rausch in the photolysis of (h -
5
C5H4PPh2)Mn(CO)3 in THF.7
The spectroscopic data for these derivatives resemble those
reported for the analogous cyclopentadienyl carbonyl rhenium
complex containing phosphine20 or phosphite21 and the precursor
5
(h -C5H4PPh2)Re(CO)3.7 For example, the IR spectra for 1 and
2 showed two n(CO) absorption bands at 1923, 1852 and 1947,
1877 cm-1 respectively, which are almost identical to the ones mea-
sured for CpRe(CO)2(PR3).20 Similarly in the 31P NMR spectra,
the phosphorus (bound to Re) chemical shifts are comparable to
the above complexes. Also, the 1H and 31P NMR spectra showed
similar chemical shifts for both hydrogen and phosphorus nuclei
5
of the (h -C5H4PPh2) group to the ones reported for the precursor
5
(h -C5H4PPh2)Re(CO)3.7,10,22
Compounds 1 and 2 react with PdCl2(NCPh)2 in CHCl3
5
to yield the unexpected bimetallic derivatives (CO)2(PR3)(h -
C5H4PPh2)RePdCl2 R = Me, (3); R = OMe, (4), (see Scheme 2).
5
Fig. 1 Molecular structure of (CO)2(PMe3)(h -C5H4PPh2)RePdCl2 (3)
drawn with 30% probability displacement ellipsoids. Hydrogen atoms and
solvent molecules are omitted.
Table 1 contains a summary of the crystallographic information,
while selected measured and calculated bond lengths and angles
are included in Table 2.
Scheme 2
5
Neither the coordination product (CO)2(R3P)Re(h -
C5H4PPh2)PdCl2(NCMe) (similar to (CO)3Re(h -C5H4PPh2)-
5
Table 1 Summary of crystallographic data and structure refinement for
3 and 4
PdCl2(NCMe)10) nor any other intermediates were observed. Both
complexes were isolated as pure samples, based on the elemental
analyses which are in good agreement with the proposed formula.
Our first suspicion about the unusual structure of these new
compounds was obtained from IR spectroscopy. The IR spectra
of 3 and 4 (in MeCN) showed two n(CO) absorptions (expected
for a dicarbonyl-phosphine or phosphite) shifted to a higher
wavenumber compared to their precursor, with a typical pattern of
a four-legged piano-stool type of structure with the two carbonyl
groups with a trans arrangement (the higher wavenumber
absorption being the less intense of the pair). By considering
3·2CH3CN
4·CH2Cl2
Empirical Formula
C26H29Cl2N2O2P2PdRe
C23H25Cl4O5P2PdRe
877.77
Formula mass/g mol-1 826.95
Collection T/K
Crystal system
Space group
298(2)
Orthorhombic
Pna21
16.853 (2)
17.329(2)
10.1789(13)
2972.8(7)
4
150(2)
Orthorhombic
Pbca
19.1773 (6)
13.3897(4)
22.1610(7)
5690.5(3)
8
˚
a/A
˚
b/A
˚
c/A
3
˚
V/A
Z
23
Dc/g cm-3
Crystal size/mm
F(000)
1.848
0.36 ¥ 0.24 ¥ 0.19
1600
2.049
0.38 ¥ 0.28 ¥ 0.08
3376
our IR values and those reported for trans-CpRe(CO)2X2
24
and trans-CpMeRe(CO)2X2 we considered that these new
compounds also possess a trans stereochemistry at the rhenium
center. This finding means that the rhenium atom is involved in
a bonding interaction with the palladium(II) center. The H and
31P NMR of the (h -C5H4PPh2) group did not show any unusual
features when compared with the data measured for the same
group in (CO)3Re(h -C5H4PPh2)PdCl2(NCMe).10
With the aim to obtain more insight into the proposed
rhenium-palladium bond we undertook a crystallographic study
of complexes 3 and 4 (see below).
m/mm-1
4.986
5.403
q range (◦)
Range h,k,l
2.32 to 28.02
-20/21, -22/19,
-13/12
1.84 to 27.89
-25/25, -17/17,
-29/28
1
5
No. total refl.
14883
72639
No. unique refl.
Data/restrains/
parameters
6413 [R(int) = 0.0656]
6555 [R(int)=0.0733]
5
6413/1/330
6555/0/328
Final R [I > 2s(I)]
R1 = 0.0692
wR2 = 0.1255
R1 = 0.0969
wR2 = 0.1358
1.059
R1 = 0.0327
wR2 = 0.0826
R1 = 0.0398
wR2 = 0.0858
1.052
R indices (all data)
2. X-Ray structure of 3·2CH3CN and 4·CH2Cl2
Goodness of fit/F2
Largest diff. peak and
hole/e A
3.111 and -1.867
3.535 and -1.065
The bimetallic complexes 3 and 4 crystallise with two acetonitrile
molecules and one dichloromethane molecule, respectively.
-3
˚
6296 | Dalton Trans., 2010, 39, 6295–6301
This journal is
The Royal Society of Chemistry 2010
©

View Article Online
◦
˚
Table 2 Selected experimental and calculated bond lengths (A) and angles ( ) for 3 and 4
Distances
3
4
Angles
3
4
Re–Pd
2.763(1) 2.798a
1.943(6) 1.970a
1.949(16) 1.926a
1.951(18) 1.943a
2.367(4) 2.374a
1.820(20) 1.819a
1.108(16) 1.168a
2.190(4) 2.230a
2.394(4) 2.364a
2.351(3) 2.349a
2.774(1) 2.800a
1.938(2) 1.972a
1.936(4) 1.926a
1.933(4) 1.954a
2.315(1) 2.324a
1.796(4) 1.813a
1.143(5) 1.168a
2.194(1) 2.251a
2.388(1) 2.350a
2.361(1) 2.365a
Re–Pd–P(1)
77.87(9) 79.9a
77.67(3) 78.9a
Re–Cpb
Re–Pd–Cl(1)
P(1)–Pd–Cl(2)
P(1)–Pd–Cl(1)
Cl(1)–Pd–Cl(2)
P(2)–Re–Pd
98.86(11) 98.6a
91.61(13) 87.4a
175.39(16) 175.6a
91.47(14) 93.7a
131.79(10) 129.2a
102.3(7) 102.3a
106.0(4) 101.9a
110.7(6) 103.4a
173.3 (14) 170.7a
170.4(17) 165.4a
109.63(19) 107.0a
118.5(2) 123.2a
124.8(4) 124.8a
128.8(5) 125.3a
99.51(3) 100.0a
89.39(4) 88.2a
Re–C(6)
Re–C(7)
Re–P(2)
P(1)–C(1)
O(1)–C(6)
Pd–P(1)
Pd–Cl(1)
Pd–Cl(2)
177.06(4) 173.8a
93.37(4) 92.2a
133.43(3) 129.3a
102.80(17) 103.8a
104.84(13) 103.8a
109.16(18) 109.0a
173.2(4) 171.7a
172.5(4) 164.4a
109.13(5) 108.2a
117.09(6) 121.8a
125.71(13) 124.3a
126.72(14) 124.0a
C(6)–Re–C(7)
C(1)–P(1)–Pd
C(11)–P(1)–C(17)
O(1)–C(6)–Re
O(2)–C(7)–Re
Cpb–Re–Pd
Cpb–Re–P(2)
Cpb–Re–C(6)
Cpb–Re–C(7)
a Gas phase optimization with the ADF+ZORA method. b Centroid (C5H4PPh2).
5
Fig. 2 Molecular structure of (CO)2(P(OMe)3)(h -C5H4PPh2)RePdCl2 (4) drawn with 30% probability displacement ellipsoids. Hydrogen atoms and
solvent molecules are omitted.
The most important features of the structure of 3 and 4, are
the presence of a four membered bimetallic ring Cp–Re–Pd–P
(assuming the whole Cp participates as a single unit of the ring).
In this ring there is a strong bimetallic interaction between the
Relativistic Density Functional Theory Calculations have also
been carried out (see below).
=
The existence of a Re Pd bond represents the key feature
determining the overall arrangement of the entire molecule.
˚
rhenium and palladium atoms with a bond distance of 2.763(1) A
For example, in complex 3 the phosphorus atom attached
to the Cp ring is deviated 0.670 A below the least squares
˚
˚
for 3 and 2.774(1) A for 4. Both distances are significantly shorter
than the sum of the respective covalent radii (2.85 A)25 and the Re–
(l.s.) plane formed by the ring, very similar to the deviation
˚
˚
˚
Pd single bond (2.8580(5) A) found in the complex Pd2Re2(CO)8(m-
obtained for the complex 4 (0.655 A), whereas a deviation of
SnPh2)2(PBut)2.26 On this criterion, as well as the correlation
between the Re–Pd bond length found in 3 and 4 and that
reported for the complex (PCy2)(PMe3)2Re(m-PCy2)2Pd(PMe3)
(2.7575(9) A), we consider that our products also have a Re Pd
double bond. In order to probe the bonding in these complexes
0.234 A above the l.s. plane was found in the closely related
complex (CO)3Re(h -C5H4PPh2)PdCl2(NCMe), which does not
have a bonding interaction between the rhenium and palladium
atoms.10 The short distance between the metal centers also
˚
5
27
˚
=
˚
exerts a shortening of the Pd–P bond (2.190(4) A in 3 and
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 6295–6301 | 6297
©

View Article Online
˚
2.194(1) A in 4) when compared to the similar distances mea-
5
10
˚
sured in (CO)3Re(h -C5H4PPh2)PdCl2(NCMe) (2.2217(13) A),
(NO)(PPh3)(h -C5H4PPh2)Re(m-CH2)PPh2PdCl2 (2.248(3) A)
5
8
˚
and in the related phosphinoferrocene complex trans-
28
˚
[PdMeCl(PPh2Fc)2], (2.3328(10) A).
Significant variations from the ideal square-planar geometry are
also observed around the Pd center. The Re–Pd–P(1) and Re–Pd–
Cl(1) angles deviate to about 77.7◦ and 99.0◦ respectively, far from
the 90◦ expected for a normal square planar coordination around
Pd. The rhenium environment is also affected by the presence of
the intermetallic bond, for example the Cp–Re–Pd angle is close to
109◦, and differs strongly from the values of the other bond angles
measured for the Cp–Re axis and the two Re–CO and Re–P(2)
(~126◦ and 117.5◦, respectively). Similar deformations have been
previously reported for related angles in complexes having a four
member bimetallic ring Cp–M–Pd–P (M = Mo, W).14,29 Despite
the variations already mentioned, the Re–CO distances and OC–
Re–CO interbond angles are comparable to those measured
in other trans dicarbonyl cyclopentadienyl rhenium complexes,
possessing a four legged piano stool type of structure.30,31
Fig. 3 Density surface picture of the s and p bonds in the Re–Pd fragment
of the complex (CO)2(PMe3)(h -C5H4PPh2)RePdCl2 (3).
5
=
To further explain the existence of the Re Pd bond, we plotted
in Fig. 5 and 6 the Mulliken charge distribution over the Re and
Pd centers in compounds 3 and 4. Calculations demonstrate that
the charge on the Pd atom is almost the same in both compounds
while the Re atom is more negatively charged in compound 4. The
=
Re Pd bond can be interpreted as electron donation from the
more electron rich Re(I) to the high valent and less electron rich
Pd(II).
The charge difference between the rhenium centers in 3 and
4 can be explained by considering the large s donor capability
of the trimethylphosphine compared to the trimethylphosphite
ligand, accordingly the more positive charge calculated for the
phosphorous atom of P(OMe)3 is indicative of its weakest s donor
and strongest p acceptor abilities. These quantum chemical results
are also experimentally supported by the 31P chemical shifts (115.7
and 27.0 ppm for P(OMe)3 in 4 and PMe3 in 3, respectively) and
by the shift to a higher energy of the n(CO) frequencies observed
in the IR spectra of 4 compared to 3 (1986, 1934 cm-1 for 4 vs.
1972, 1916 cm-1 for 3).
3. Theoretical calculations
The geometry optimization of the complexes was performed using
the ADF code.32 All the calculated bond distances and bond
angles, included in Table 2, are in reasonable agreement with the
measured experimental values, indicating that this method, which
includes scalar relativistic effects, is quite efficient for optimizing
geometries of complexes containing heavy metals.
The calculations clearly show the existence of a double bond
Conclusion
˚
=
between the rhenium and palladium atoms (Re Pd) of 2.798 A
5
˚
(3) and 2.800 A (4) which compares well with the distance of
2.763(1) A (3) and 2.774(1) A (4) determined by X-ray diffraction
and with the distance of 2.7575(9) A measured in a binuclear
Herein we have shown that the new electron-rich complexes (h -
˚
˚
C5H4PPh2)Re(CO)2PR3 (1 and 2) behave as neutral chelating
ligands and coordinate to the Pd(II) center through the phosphine
side arm of the cyclopentadienyl group and the rhenium atom.
This coordination mode resembles the one observed in binuclear
˚
27
=
Re Pd complex reported by Baker et al.
=
In order to clarify the s and p character of the Re Pd double
5
bond, we carried out a fragment analysis in compounds 3 and 4,
which is graphically depicted in Fig. 3. The interaction between the
Re(5dz2) and the Pd(4dz2) orbitals gives rise to the ds bond, while
the interaction between the Re(5dxz) and the Pd(4dxz) orbitals
gives rise to the dp bond. In Fig. 4, we show the principal levels
complexes containing the anionic ligand [(h -C5H4PPh2)M(CO)3]-
(M = Mo, W), but contrasts with the coordination capability
5
of the analogous (h -C5H4PPh2)Re(CO)3 which acts only as
monodentate ligand.
The X-ray structure of the two binuclear complexes clearly
reveals a strong bonding interaction between the rhenium and
palladium atoms. Relativistic Density Functional Theory Calcu-
lations proved useful in supporting the existence of a double bond
between the two transition metals.
=
involved in a Re Pd p bond.
The orbital percent composition shown in Table 3 indicates
those MO’s with major Re and Pd content which are involved in
bonding interactions.
Table 3 Percent (%) contributions of selected molecular orbitals of compounds 3 and 4
HOMO-3
HOMO-2
HOMO-1
HOMO
LUMO
LUMO+1
LUMO+2
LUMO+3
3
4
74.2% Cl
14.7% Pd
2.7% P
41.5% Cl
36.9% Pd
12.5% Re
72.9% Cl
20.1% Pd
1.1% Re
73.4% Cl
16.1% Pd
2.9% Re
31.3% Pd
22.3% Cl
15.4% P
10.0% Re
5.8% C
31.2% Pd
23.8% Cl
15.2% P
10.1% Re
7.2% C
85.7% C
9.6% P
73.3% C
5.4% P
2.2% O
53.7% C
16.3% O
10.7% Re
1.9% Pd
1.9% Re
77.5% Cl
11.5% Pd
2.5% P
41.6% Cl
37.4% Pd
11.3% Re
72.5% Cl
18.2 Pd
71.8% Cl
16.7% Pd
2.4% Re
77.7% C
10.3% P
61.6% C
8.7% O
3.7% Re
2.3% P
68.4% C
7.3% Re
5.9% O
2.4% Pd
1.9% Re
1.3% Pd
6298 | Dalton Trans., 2010, 39, 6295–6301
This journal is
The Royal Society of Chemistry 2010
©

View Article Online
Fig. 4 Calculated MO’s scheme for 3, showing the principal levels involved in p Re–Pd bonding.
Fig. 5 Mulliken charge distribution over Re, Pd and P centers for 3.
Fig. 6 Mulliken charge distribution over Re, Pd and P centers for 4.
Experimental
Elmer FT-IR Spectrum One spectrophotometer in a KBr solution
cell. Photochemical reactions were carried out at 300 nm with a
Rayonet RPR 100 photoreactor in Pyrex tubes. Elemental analyses
were obtained at the Centro de Instrumentacio´n, Pontificia
Universidad Cato´lica de Chile, Santiago, Chile.
All experiments were carried out under a nitrogen atmosphere
using standard Schlenck techniques. Solvents were purified
as follows: hexane and tetrahydrofuran by distillation from
sodium/benzophenone ketyl; dichloromethane, chloroform and
acetonitrile by distillation from P2O5. The compounds PMe3,
P(OMe)3 and PdCl2(NCPh)2 (Aldrich) were use as received.
Synthesis of (g5-C5H4PPh2)Re(CO)2PR3 (1 and 2)
5
The organometallic ligand (h -C5H4PPh2)Re(CO)3 was prepared
according to the procedure reported by Gladysz.22 NMR spectra
were recorded on a Bruker AVANCE 400 MHz spectrometer;
1H and 13C were referenced to a residual solvent signal and
A Pyrex tube was charged with (h -C5H4PPh2)Re(CO)3 (90 mg,
5
0.173 mmol), dissolved in 20 mL of dry THF and sealed with
a rubber septum. This solution was purged with N2 for 5 min,
after which the PR3 was added (0.30 mmol). The colorless
reaction mixture was irradiated at 300 nm and monitored by IR
1
31P{ H}NMR chemical shifts were referenced to 85% H3PO4
as an external standard. IR spectra were recorded on a Perkin-
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 6295–6301 | 6299
©

View Article Online
spectroscopy until the n(CO) absorption bands of the precursor
almost disappeared (about 2 h). The resulting yellow solution
was evaporated to dryness and the dark-brown oil obtained
was purified through a silica gel column and eluted with a
hexane/dichlorometane 3 : 1 mixture. The first fraction moved the
unreacted precursor (about 10%) and the second fraction moved
PPh2); 115,7 (s, P(OMe)3). Anal. Calcd. for C23H25Cl4O5P2PdRe:
C 31.47, H 2.87; found: C 31.18, H 2.66.
Computational details
5
Calculations for (CO)2(PMe3)(h -C5H4PPh2)Re–PdCl2 3 and
5
5
the organometallic ligand (h -C5H4PPh2)Re(CO)2PR3.
(CO)2(P(OMe)3)(h -C5H4PPh2)Re–PdCl2 4 were carried out by
using the Amsterdam Density Functional (ADF) code.32 The
scalar relativistic effects were incorporated by using the zero
order regular approximation (ZORA).33,34 All the molecular
structures were fully optimized via the analytical energy gra-
dient method implemented by Verluis and Ziegler employing
the local density approximation (LDA) within the Vosko-Wilk-
Nusair parametrization for local exchange correlations.35,36 We
also used the GGA (Generalized Gradient Approximation) PW91
function.34 The cluster geometry optimization and the excitation
energies were calculated using standard Slater-type-orbital (STO)
basis sets with triple-zeta quality plus double polarization func-
tions (TZ2P) for all the atoms.
5
(g5-C5H4PPh2)Re(CO)2PMe3 (1). Yield based on (h -
C5H4PPh2)Re(CO)3: 46 mg, (0.081 mmol), 52%. IR [CH2Cl2,
n(CO), cm-1]: 1923 (s), 1852 (s). H-NMR (CDCl3) d: 1.68 (d,
1
2JPH = 9.8 Hz, 9H, PMe3), 5.06 (m, 2H, C5H4), 5.13 (m, 2H,
C5H4), 7.35 (m, 10H, C6H5). 13C{ H} NMR (CDCl3) d: 24.1 (d,
1
1JPC = 36.6 Hz, PMe3), 83.4 (d, JPC = 2.7 Hz, C5H4), 89.9 (d,
3
2JPC = 13.9 Hz, C5H4), 91.4 (d, 1JPC = 14.8 Hz, Cipso C5H4), 128.4
(d, 3JPC = 6.8 Hz, C6H5), 128.7 (s, C6H5), 133.4 (d, 1JPC = 19.4 Hz,
Cipso C6H5), 138.0 (d, 2JPC = 10.2 Hz, C6H5) 201.6 (d, 2JPC = 8.4 Hz,
CO). 31P{ H}-NMR (CDCl3) d: -27.3 (s, PMe3), -16.7 (s, PPh2).
1
Anal. Calcd. for C22H25O2P2Re: C 46.39, H 4.42. Found: C 46.22,
H 4.70.
(g5-C5H4PPh2)Re(CO)2P(OMe)3 (2). Yield based on (h -
5
X-ray crystal structure determinations
C5H4PPh2)Re(CO)3: 49 mg, (0.080 mmol) 51%. IR [CH2Cl2,
1
n(CO), cm-1]: 1947 (s), 1877 (s). H-NMR (CDCl3) d: 3.51 (d,
Suitable X-ray single crystals of compounds 3 and 4 were obtained
as described above and were mounted on top of glass fibers
in a random orientation. Crystal data, data collection, and
refinement parameters are given in Table 1. Compounds 3 and
4 were studied at 298(2) and 150(2) K, respectively, on a Bruker
Smart Apex diffractometer equipped with bidimensional CCD
detector employing graphite-monochromated Mo-Ka radiation
3JPH = 12.3 Hz, 9H, P(OMe3), 5.13 (m, 2H, C5H4), 5.21 (m, 2H,
1
C5H4), 7.38 (m, 10H, C6H5). 13C{ H}- NMR (CDCl3) d: 52.2
2
2
(d, JPC = 3.0 Hz, P(OMe)3), 84.9 (d, br., JPC = 2.2 Hz, C5H4),
89.1 (dd, 2JPC = 2.2 Hz, 2JPC = 13.3 Hz, C5H4), 94.4 (dd, 2JPC
=
2.2 Hz, 1JPC = 16.9 Hz, Cipso C5H4), 128.4 (d, 3JPC = 6.8 Hz, C6H5),
1
128.9 (s, C6H5), 133.5 (d, JPC = 19.6 Hz, Cipso C6H5), 137.7 (d,
2JPC = 10.5 Hz, C6H5), 198.9 (d, JPC = 13.8 Hz, CO). 31P{ H}-
1
˚
(l = 0.71073 A). The diffraction frames were integrated using the
SAINT package,37 and corrected for absorption with SADABS.38
The structures were solved using XS in SHELXTL-PC,39 by
Patterson and completed (non-H atoms) by difference Fourier
techniques. The complete structure was then refined by the full-
matrix least-squares procedures on reflection intensities (F2).40 The
non-hydrogen atoms were refined with anisotropic displacement
coefficients, and all hydrogen atoms were placed in idealized
locations.
NMR (CDCl3) d: -16,3 (s, PPh2), 138.9 (s, PMe3). Anal. Calcd.
for C22H25O5P2Re: C 42.79, H 4.08. Found: C 42.51, H 4.33.
Synthesis of (CO)2(PR3)(g5-C5H4PPh2)RePdCl2 (3 and 4)
5
(0.10 mmol) of the organometallic ligands (h -C5H4PPh2)-
Re(CO)2PR3 (1 or 2), was poured into a 50 mL round bottom
flask equipped with a magnetic stirrer bar, and dissolved in 15 mL
of dry chloroform at room temperature. To this solution 38.4 mg
(0.100 mmol) of solid PdCl2(NCPh)2 was added. The resulting
orange mixture was stirred and refluxed under a N2 atmosphere for
6 h. After this period an orange solid was formed. The solvent was
evaporated to dryness and the residual orange solid dissolved in
acetonitrile and allowed to crystallize at low temperature. In both
cases the bimetallic complexes were isolated as orange crystals
suitable for X-ray diffraction.
Acknowledgements
This work has been supported by Fondecyt No. 1060487 and
1070345. D. S. and R. R.-T. are grateful to CONICYT-fellowship.
A. K. acknowledges DI-Pontificia Universidad Catolica de Val-
paraiso. R. A.-P. thanks MECESUP2-FSM0605 and UNAB-DI-
42-06/R, UNAB-DI-05-06/I.
(CO)2(PMe3)(g5-C5H4PPh2)RePdCl2 (3). Yield: 65 mg,
(0.087 mmol) 87%. IR (nCO) (CH3CN) (cm-1): 1972 (m); 1916 (s);
References
2
1H-NMR (CD3SOCD3) d: 1.92 (d, JPH = 11.3 Hz, 9H, PMe3);
1 M. Herberhold, Ferrocene Compounds Containing Heteroelements,
in Ferrocenes: Homogeneous Catalysis-Organic Synthesis-Materials
Science, VCH, Weinheim. 1995, 22.
2 R. C. J. Atkinson, N. J. Long, Monodentate Ferrocene Donor Ligands
in Ferrocenes: Ligands, Materials and Biomolecules, John Wiley & Sons
Ltd., 2008, 3.
3 X. D. He, A. Maisonnat, F. Dahan and R. Poliblanc, Organometallics,
1989, 8, 2618.
4 M. D. Rausch, B. H. Edwards, R. D. Rogers and J. L. Atwood, J. Am.
Chem. Soc., 1983, 105, 3882.
5 M. S. Blais, R. D. Rogers and M. D. Rausch, J. Organomet. Chem.,
2000, 593–594, 142.
4.86 (m, 2H, C5H4); 5.90 (m, 2H, C5H4); 7.50–8.50 (m, 10H,
1
C6H5). 31P{ H}-NMR (CD3CN) d: -26.3 (s, PMe3); 27.0 (d,
3JPP = 4.8 Hz, PPh2). Anal. Calcd. for C26H29Cl2N2O2P2PdRe: C
37.76, H 3.53; found: C 37.92, H 3.70.
(CO)2(P(OMe)3)(g5-C5H4PPh2)RePdCl2 (4). Yield: 66 mg,
(0.083 mmol) 83%. IR (nCO) (CH3CN) (cm-1): 1986 (m); 1934 (s).
3
1H-NMR (CD3CN) d: 3.78 (d, JPH = 12.3 Hz; 9H; P(OMe)3),
4.84 (m, 2H, C5H4), 5.63 (m, 2H, C5H4), 7.58 (m, 7H, C6H5), 8.32
1
(m, 3H, C6H5). 31P{ H}-NMR (CD3CN) d: 27.2 (d, 3JPP = 5.2 Hz,
6300 | Dalton Trans., 2010, 39, 6295–6301
This journal is
The Royal Society of Chemistry 2010
©

View Article Online
6 R. C. J. Atkinson, V. C. Gibson and N. J. Long, Chem. Soc. Rev., 2004,
33, 313.
7 M. D. Rausch and W. C. Spink, Synth. React. Inorg., Met.-Org., Nano-
Met. Chem., 1989, 19, 1093.
8 K. Kromm, F. Hampel and J. A. Gladysz, Helv. Chim. Acta, 2002, 85,
1778.
23 R. B. King, R. H. Reimann and D. J. Darensbourg, J. Organomet.
Chem., 1975, 93, C23.
24 J. M. Smith, L. Cheng, N. J. Coville, J. Schulte, P. S. Dimpe,
M. S. Adsetts, L. M. Cook, J. C. A. Boeyens and D. C. Levendis,
Organometallics, 2000, 19, 2597.
25 www.ccdc.cam.ac.uk/products/csd/radii.
9 K. Kromm, P. L. Osburn and J. A. Gladysz, Organometallics, 2002, 21,
4275.
26 R. D. Adams, B. Captain, M. Johansson and J. L. Smith, J. Am. Chem.
Soc., 2005, 127, 488.
10 D. Sierra, A. Mun˜oz, F. Godoy, A. H. Klahn, A. Iban˜ez, M. T. Garland
and M. Fuentealba, Polyhedron, 2009, 28, 322.
11 R. M. Bullock and C. P. Casey, Acc. Chem. Res., 1987, 20, 167.
12 C. P. Casey, R. M. Bullock, W. C. Fultz and A. L. Rheingold,
Organometallics, 1982, 1, 1591.
27 R. T. Baker, J. C. Calabrese and T. E. Glassman, Organometallics, 1988,
7, 1889.
28 S. Otto, A. Roodt and J. Smith, Inorg. Chim. Acta, 2000, 303, 295.
29 P. Cianfriglia, V. Narducci, C. Lo Sterzo and E. Viola, Organometallics,
1996, 15, 5220.
13 A. Ricci, F. Angelucci, M. Chiarini, C. Lo, Sterzo, D. Masi,
G. Giambastiani and C. Bianchini, Organometallics, 2008, 27,
1617.
14 F. Angelucci, A. Ricci, D. Masi, C. Bianchini and C. Lo, Sterzo,
Organometallics, 2004, 23, 4105.
15 C. Cornelissen, G. Erker, G. Kehr and R. Frohlich, Organometallics,
2005, 24, 214.
16 F. Angelucci, A. Ricci, C. Lo, Sterzo, D. Masi, C. Bianchini and G.
Bocelli, Organometallics, 2002, 21, 3001.
30 M. T. Garland, R. Baggio, A. H. Klahn and B. Oelckers, Acta
Crystallogr., Sect. C: Cryst. Struct. Commun., 1999, 55, 61.
31 S. W. Lee, J:A. Martin, S. G. Bott and M. G. Richmond, Inorg. Chim.
Acta, 1995, 232, 57.
32 Amsterdam Density Functional (ADF) code, release 2007, Vrije
Universiteit, Amsterdam, The Netherlands.
33 E. Van Lenthe, E. J. Baerends and G. Snijders, J. Chem. Phys., 1994,
101, 9783.
34 G. Te Velde, F. M. Bickelhaupt, S. J. A. Van Gisberger, C. Fonseca-
Guerra, E. J. Baerends, J. G. Snijders and T. J. Ziegler, J. Comput.
Chem., 2001, 22, 931.
17 B. Brumas-Soula, F. Dahan and R. Poilblanc, New J. Chem., 1998, 22,
15.
18 L. Spadoni, C. Lo Sterzo, R. Crescenzi and G. Frachey,
Organometallics, 1995, 14, 3149.
19 A. Iretskii, M. C. Jennings and R. Poilblanc, Inorg. Chem., 1996, 35,
1266.
35 L. Versluis and T. Ziegler, J. Chem. Phys., 1988, 88, 322.
36 S. H. Vosko, L. Wilk and M. Nusair, Can. J. Phys., 1980, 58, 1200.
37 SAINT-PLUS (Version 6.02), Bruker Analytical X-Ray Systems Inc.,
Madison, WI, USA, 1999.
20 R. Angelici, G. Facchin and M. M. Singh, Synth. React. Inorg.,
Met.-Org., Nano-Met. Chem., 1990, 20, 275.
21 C. Leiva, K. Mossert, A. H. Klahn and D. Sutton, J. Organomet. Chem.,
1994, 469, 69.
22 S. Eichenseher, O. Delacroix, K. Kromm, F. Hampel and J. A. Gladysz,
Organometallics, 2005, 24, 245.
38 G. M. Sheldrick, SADABS, (Version 2.05), Bruker Analytical X-Ray
Systems Inc., Madison, WI, USA, 1999.
39 SHELXTL Reference Manual (Version 6.14). Bruker Analytical X-Ray
Systems Inc., Madison, WI, USA, 1998.
40 G. M. Sheldrick, SHELX,97. Program for the Refinement of Crystal
Structures, University of Go¨ttingen,Go¨ttingen, Germany, 1997.
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 6295–6301 | 6301
©