The coordination chemistry of perfluorovinyl substituted phosphine ligands, a crystallographic and spectroscopic study. Co-crystallisation of both cis- and trans-isomers of [PtCl2{PiPr2(CFCF 2)}2] within the same unit cell

Article abstract of DOI:10.1039/b711825b

The coordination chemistry of the perfluorovinyl phosphines PEt ₂(CFCF₂), PⁱPr₂(CFCF₂), PCy₂(CFCF₂) and PPh(CFCF₂)₂ to rhodium(i), palladium(ii), and platinum(ii) centres has been investigated. The electronic properties of the ligands are estimated based on ν(CO) and ¹J(Rh-P) values. X-Ray diffraction data for the square-planar Pd(ii) and Pt(ii) perfluorovinyl-phosphine containing complexes allow estimates of the steric demand for the series of ligands PPh₂(CFCF₂), PEt₂(CFCF₂), PⁱPr₂(CFCF ₂), PCy₂(CFCF₂) and PPh(CFCF₂) ₂ to be determined. The (CFCF₂) fragment is found to be more electron withdrawing than (C₆F₅) yet sterically less demanding. These ligands therefore provide a range of electron-neutral to phosphite-like electronic properties combined with a range of steric demands. This study also reveals that short intramolecular interactions from the metal centre to the β-fluorine atom cis to phosphorus of the CFCF₂ groups are observed in all-trans square planar complexes of the ligands. Unusually, the complex [PtCl₂{PⁱPr₂(CFCF ₂)}₂] crystallises with both cis- and trans-isomers present in the unit cell. It appears that co-crystallisation of both isomers occurs in order to maximise fluorous regions in the crystal packing, and the extended structure displays short fluorine-fluorine contacts. The generation of mixed geometries seems to be a phenomenon of crystallisation, as solution phase NMR studies reveal the presence of only the trans-isomer. The Royal Society of Chemistry.

Full text of DOI:10.1039/b711825b

View Article Online / Journal Homepage / Table of Contents for this issue
PAPER
www.rsc.org/dalton | Dalton Transactions
The coordination chemistry of perfluorovinyl substituted phosphine ligands, a
crystallographic and spectroscopic study. Co-crystallisation of both cis- and
i
=
trans-isomers of [PtCl2{P Pr2(CF CF2)}2] within the same unit cell†
Nicholas A. Barnes, Alan K. Brisdon,* F. R. William Brown, Wendy I. Cross, Christopher J. Herbert,
Robin G. Pritchard and Ghazala Sadiq
Received 2nd August 2007, Accepted 19th October 2007
First published as an Advance Article on the web 5th November 2007
DOI: 10.1039/b711825b
i
=
=
The coordination chemistry of the perfluorovinyl phosphines PEt2(CF CF2), P Pr2(CF CF2),
=
=
PCy2(CF CF2) and PPh(CF CF2)2 to rhodium(I), palladium(II), and platinum(II) centres has been
investigated. The electronic properties of the ligands are estimated based on m(CO) and 1J(Rh–P)
values. X-Ray diffraction data for the square-planar Pd(II) and Pt(II) perfluorovinyl-phosphine
=
containing complexes allow estimates of the steric demand for the series of ligands PPh2(CF CF2),
i
=
=
=
=
PEt2(CF CF2), P Pr2(CF CF2), PCy2(CF CF2) and PPh(CF CF2)2 to be determined. The
=
(CF CF2) fragment is found to be more electron withdrawing than (C6F5) yet sterically less
demanding. These ligands therefore provide a range of electron-neutral to phosphite-like electronic
properties combined with a range of steric demands. This study also reveals that short intramolecular
=
interactions from the metal centre to the b-fluorine atom cis to phosphorus of the CF CF2 groups are
observed in all-trans square planar complexes of the ligands. Unusually, the complex
i
=
[PtCl2{P Pr2(CF CF2)}2] crystallises with both cis- and trans-isomers present in the unit cell. It appears
that co-crystallisation of both isomers occurs in order to maximise fluorous regions in the crystal
packing, and the extended structure displays short fluorine–fluorine contacts. The generation of mixed
geometries seems to be a phenomenon of crystallisation, as solution phase NMR studies reveal the
presence of only the trans-isomer.
ligands occupy about half of the available map and that there
Introduction
are still few readily-accessible, sterically-demanding, electron-poor
P(III) ligand systems. This is unfortunate since in some cases these
are exactly the types of ligand that have been shown to demonstrate
enhanced reactivity and catalytic properties.7
Phosphorus(III) ligand systems are amongst the most widely
studied and utilized in transition metal chemistry.1 The majority of
these ligands are tertiary phosphines, PR3, or phosphites, P(OR)3,
both of which offer the opportunity to vary the properties of the
ligand by changing the nature of the organic substituents. In doing
so it is possible to modify the physical and chemical properties of
the ligand, and of their metal complexes, a number of which are
important catalysts.
Two of the more important variables in these systems are steric,
usually denoted by the Tolman cone angle2 (or variants thereof)
and electronic, which is most often characterised by the CO
stretching frequency of an appropriate transition metal carbonyl
complex, such as [Ni(CO)3P], [Mo(CO)5P] or [Rh(CO)ClP2] (P =
P(III) ligand). There have been many reports,3 both theoretical
and experimental, measuring and rationalising the steric and
electronic properties of P(III) systems, with much of our current
understanding still being based on the original work of Chatt4 and
Tolman.2 Notable recent contributions in this area include work
on generating a ligand knowledge base for P(III) systems5 and
the mapping of the steric/electronic parameter-space for P(III)
systems.6 The latter showed that the majority of known phosphine
Organofluorine-substituted phosphine ligands offer an oppor-
tunity to access this currently poorly represented area. Thus,
by incorporating organofluorine groups onto a P(III) centre it is
possible to generate ligands with r-donation properties more akin
to those of phosphites, but with a steric demand comparable to
that found for phosphines, which results in fluorinated phosphines
being distinct from both perprotio-phosphines and phosphites.8
The current range of organofluoro-phosphines is still quite small,
with the majority containing fluoroaryl substituents9 (by virtue of
the commercial availability of suitable precursors and the stability
10
of their metal derivatives) or small fluoroalkyl groups such as CF3
or C2F5.11 Phosphines possessing long fluorinated chains, such as
CH2CH2(CF2)nCF3 (n = 5, 7) are also known, which are designed
to render the phosphines, and their complexes, preferentially
soluble in fluorous solvents and form the basis of fluorous-biphase
systems.12 However, these materials specifically include a non-
fluorinated “spacer” group to insulate the phosphorus centre from
the electron-withdrawing properties of the fluorocarbon chain and
because of this usually have a steric demand similar to the parent
phosphine.
School of Chemistry, The University of Manchester, Manchester, UK M13
9PL. E-mail: alan.brisdon@manchester.ac.uk
† CCDC reference numbers 656532–656542. For crystallographic data in
CIF or other electronic format see DOI: 10.1039/b711825b
We have previously reported the synthesis of the thermally
and oxidatively stable, perfluorovinyl (pfv) containing phosphines
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 101
©

View Article Online
derived from the commercially available hydrofluorocarbon re-
frigerant HFC-134a (CF3CH2F).13–14 Although prior reports of
perfluorovinyl-containing phosphines existed, dating back to
1960,15 there were no reports of their coordination chemistry
until 1999.14 Subsequently we, and others, have reported on
the coordination chemistry of these ligands,16–19 but even so the
total number of reported complexes is far less than the many
The signals of 2, 3 and 4 showed a virtual doublet of triplets
at room temperature, while those of 1 and 5 were broad and
required cooling to 233 K before the additional coupling was
resolved. A similar effect has been observed for other rhodium(I)
phosphine complexes such as trans-[RhCl(CO){P(C6H3F2-2,6)3}2]
which is ascribed to hindered rotation about the P–C bonds.21
These complexes exhibit |1J(RhP)| couplings of between 128
and 142 Hz, which are greater than has been observed for
the analogous vinyl-containing (124.5 Hz)20 and triphenylphos-
phine complexes (126.9 Hz),22 but comparable to that found
for other fluorine-containing phosphine ligands, e.g. for trans-
[RhCl(CO){PPh2(C6F5)}2], 1J(RhP) = 133.0 Hz,23 and for the
PPh(C6F5)2 analogue 1J(RhP) = 136 Hz.
reported complexes of vinyl-containing phosphines, especially
20
=
=
PPh2(CH CH2), and PPh(CH CH2)2. Despite the scarcity of
fluorovinyl-phosphine complexes, the perfluorovinyl-containing
ligands have been included in computational studies6 along
with CF3, C2F5 and C6F5-containing phosphines since these are
essentially the only well established organo-fluorine containing
phosphines. However, there is no experimental data with which to
compare the perfluorovinyl-containing phosphines. Nor has there
been any detailed comparison of the relative steric and electronic
properties of the available organo-fluorine substituents. We have
therefore undertaken a systematic study of the coordination
chemistry of a series of perfluorovinyl-containing phosphine
ligands with a range of ancillary substituents in order to assess
their properties.
The presence of the perfluorovinyl group in complexes 1 to
5 is established unequivocally by 19F NMR spectroscopy—three
mutually coupled doublet of doublet based signals for the AMX
spin system are observed at ca. −80, −100, and −180 ppm,
which are assigned to the trans-, cis- and gem-fluorine nuclei
respectively.14,24 Additionally, PF coupling is observed (in all
cases) on the resonance assigned to the gem-fluorine nucleus. In
1
complexes 1–4 this coupling appears in both the 19F and 31P{ H}
NMR spectra as a virtual triplet, indicative of a system with
mutually trans-phosphine ligands whilst for complex 5 a virtual
Results and discussion
=
quintet is observed as a result of the ligand being bis-CF CF2
The air-and moisture stable perfluorovinyl-containing phos-
substituted. All the complexes show an increase in magnitude of
2
the J(PF) coupling constant compared to the free ligands,14,16,17
=
=
phines PPh2(CF CF2), PCy2(CF CF2) (Cy = cyclohexyl),
i
=
=
P Pr2(CF CF2) and PEt2(CF CF2) were successfully prepared
but no discernible J(RhF) coupling is resolved.
using the previously reported method.14,17 Attempts to prepare
pure samples of the bis-perfluorovinyl containing phosphines
Vibrational spectroscopic features
i
=
=
=
PCy(CF CF2)2, P Pr(CF CF2)2 and PEt(CF CF2)2 were less
successful, in each case a mixture of products being ob-
tained, which were difficult to completely separate, however
The infra-red spectra of 1 to 5 all display four IR bands characteris-
=
tic of a perfluorovinyl-containing compound: viz. m(C C) at 1720–
PPh(CF CF2)2 was readily isolable. The resulting ligands were
40 cm−1 and three m(C–F) bands at 1304–14, 1146–57 and 1028–
=
subsequently complexed to rhodium, palladium and platinum
metal centres, as outlined in Scheme 1 below.
51 cm−1.25 An evaluation of the electronic effects of the different
combinations of alkyl, aryl and perfluorovinyl groups in the
i
=
=
ligands PR2(CF CF2) (R = Ph, Cy, Pr, Et), and PPh(CF CF2)2
can be undertaken by comparison of the m(C≡O) frequencies
=
of complexes 1 to 5. For trans-[RhCl(CO){PPh2(CF CF2)}2],
1, this is observed at 1989 cm−1. As anticipated, this is at
higher frequency than the CO stretch for trans-[RhCl(CO)(PPh3)2]
(1964 cm−1)22 indicating a reduction in back bonding upon
substitution of a phenyl group for an electron-withdrawing
perfluorovinyl group in the phosphine ligand. This trend continues
=
for the complex of PPh(CF CF2)2, 5, where m(C≡O) is observed
at 2002 cm−1, which is only a little lower than that found for
trans-[RhCl(CO){P(C6F5)3}2] (2008 cm−1).23 For the complexes of
Scheme 1
i
=
=
the remaining phosphines PEt2(CF CF2), 2, P Pr2(CF CF2), 3,
=
and PCy2(CF CF2), 4, the absorptions are at 1981, 1981 and
1979 cm−1 respectively. This suggests that they possess, essentially,
the same electronic properties, lying mid-way between the PPh3
and P(C6F5)3 analogues.
Synthesis and characterisation of
=
trans-[RhCl(CO){PR3−n(CF CF2)n}2] complexes
The reaction of four equivalents of the perfluorovinyl-containing
ligands with [Rh(l-Cl)(CO)2]2 (Scheme 1) resulted in a series of
Cundari et al.6 reported semi-empirical electronic parameter
(SEP) values derived from calculations of the CO stretching
frequency of [RhCl(CO)P2] complexes (P = P(III) ligand) for
=
yellow solids formulated as trans-[RhCl(CO){PR3−n(CF CF2)n}2]
(n = 1, R = Ph 1, Et 2, iPr 3, Cy 4; n = 2, R = Ph 5) on the basis
both PPh2(CF CF2) and PPh(CF CF2)2. Whilst the values
obtained are ca. 7–10% higher than the experimental data they
can still be used for comparison. The computed data suggest
=
=
of analytical and spectroscopic data, see Table 1.
1
The 31P{ H} NMR spectra for 1 to 5 each show a resonance
=
which is shifted to higher frequencies (by 30–55 ppm) with respect
to the free ligand, which is consistent with complex formation.
that the perfluorovinyl-containing phosphine PPh2(CF CF2)
[SEP = 2124 cm−1] possesses similar electronic properties to
102 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 103
©

View Article Online
PPh(C6F5)2 [SEP = 2123 cm−1]. However, the experimental data
for PPh3−n(CF CF2)n [n = 1, 1989; n = 2, 2002 cm−1] and
=
PPh3−n(C6F5)n [n = 1, 1982; n = 2, 1996 cm−1]23 suggests that the
perfluorovinyl group is slightly more electron-withdrawing than
1
C6F5. This is supported by the J(RhP) coupling constants, vide
supra, where slightly larger values are observed for perfluorovinyl-
containing phosphines compared with C6F5-containing ana-
logues. Furthermore, the Tolman electronic parameter26 vi derived
from the m(CO) stretching data and the previously reported
empirical relationship between CO-stretching frequencies of
[Rh(CO)ClP2] and [Ni(CO)3P] complexes,27 gives a value of 11.2
for the C6F5 group while for the C2F3 group the average value
determined from complexes 1–5 is 12.3. This places the perfluo-
rovinyl group between that of C6F5 and chlorine (vi = 14.8) on this
scale. Unfortunately analogous data for the trifluoromethyl- and
pentafluoroethyl-containing phosphines are not available, so it is
not possible to make a similar comparison with those ligands.
Fig. 1 ORTEP representation of the structure of 1. Thermal ellipsoids
are shown at the 30% level. Selected bond lengths: Rh1–C1 1.827(9),
Rh1–P1 2.304(2), Rh1–P2 2.297(2), Rh1–Cl1 2.349(2), P1–C14 1.790(9),
˚
=
P1–C8 1.812(8), P1–C2 1.815(8), C1–O1 1.101(9) A. Selected bond angles:
Crystal structure of trans-[RhCl(CO){PPh2(CF CF2)}2], 1
C1–Rh1–P1 90.9(3), C1–Rh1–P2 91.0(3), P1–Rh1–P2 77.5(3)◦.
Attempts were made to grow crystals for X-ray diffraction work for
complexes 1–5, however, only for complex 1 were suitable crystals
obtained. Analysis of the data (Table 2) confirm the complex to
˚
˚
range 2.280–2.433 A, mean 2.328(5) A; d(Rh–Cl): range 2.341–
˚
2.422, mean 2.375(3) A, sample size: 38]. These shorter than
=
be trans-[RhCl(CO){PPh2(CF CF2)}2], the molecular structure
average distances for 1 are anticipated for the presence of the
electron-withdrawing group in the phosphine and are comparable
with those found in other organofluoro-phosphine containing
complexes e.g. trans-[RhCl(CO){PPh(C6H3F2-2,6)2}2]; Rh–P =
of which is shown in Fig. 1.
The rhodium centre in 1 lies in a slightly distorted square
planar environment, with Rh–P bond lengths of 2.304(2) and
2.297(2) A, and d(Rh–Cl) = 2.349(2) A. The Rh–P and Rh–Cl
bonds are shorter than the average values for monomeric trans-
[RhCl(CO)(PR3)2] complexes containing perprotio phosphines
reported in the Cambridge Structural Database28 [d(Rh–P):
21
˚
˚
˚
2.3100(13) A.
˚
Whilst the Rh–C distance of 1.827(9) A in 1 is the same
as that of the non-fluorinated analogue trans-[RhCl(CO)-
20
˚
=
{PPh2(CH CH2)}2] (1.827(1) A), the C≡O distance in 1
i
i
=
=
Table 2 Crystallographic data for trans-[Rh(CO)Cl{PPh2(CF CF)}2], 1, [PdX2{PR2(CF CF2)}2] (X = Cl, R = Pr 9; X = Br, R = Pr 10; X = Cl, R =
=
Cy, 12) and [PdX2{PPh(CF CF2)2}2] (X = Br, 14; X = I, 15)
1
9
10
12
14
15
Formula
C29H20ClF6OP2Rh C16H28Cl2F6P2Pd C16H28Br2F6P2Pd C28H44Cl2F6P2Pd
C20H10Br2F12P2Pd
806.44
Triclinic
¯
P1
9.105 (2)
10.013 (1)
7.870 (1)
109.062 (10)
102.91 (2)
99.26 (2)
639.4 (2)
1
C20H10F12I2P2Pd
900.42
Triclinic
¯
P1
9.9798 (10)
11.4305 (10)
12.382 (2)
106.783 (10)
94.101 (10)
102.413 (10)
1307.1 (3)
2
Formula weight
Crystal system
Space group
698.75
Monoclinic
P21/n
573.62
Triclinic
¯
P1
662.54
Monoclinic
P21/n
733.87
Triclinic
¯
P1
˚
a/A
11.688 (2)
23.638 (3)
11.873 (2)
90
114.83 (2)
90
8.090 (2)
8.3232 (14)
9.2824 (13)
80.593 (12)
77.717 (16)
70.897 (16)
574.08 (19)
2
9.7399 (2)
11.6112 (3)
10.7920 (3)
90
93.697 (1)
90
11.2691 (6)
11.6674 (6)
14.9514 (9)
74.405 (2)
70.092 (3)
63.955 (3)
1644.00 (16)
2
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
3
˚
V/A
Z
2977.1 (9)
4
1217.95 (5)
2
T/K
293 (2)
1.559
203 (2)
1.659
293 (2)
1.807
150 (2)
1.483
293 (2)
2.094
293 (2)
2.288
Dc/g cm−3
Crystal size/mm
0.25 × 0.25 × 0.1
0.25 × 0.15 × 0.1 0.07 × 0.15 × 0.2 0.25 × 0.04 × 0.01 0.25 × 0.15 × 0.15 0.10 × 0.15 × 0.25
l/mm−1
0.830
1.227
4.219
0.875
11.628
0.926
2h range/◦
3.40 → 50
5474
5211 (0.0360)
2974
4.52 → 49.96
6.4 → 50
4.52 → 49.96
6.8 → 65.0
3 → 50.00
Total reflections
Unique reflections (Rint
Observed reflections
[I > 2r(I)]
2152
19675
22106
2191
4874
)
2152
1994
2786 (0.052)
2083
5820 (0.091)
4101
2048 (0.056)
1474
4383 (0.021)
3784
Parameters
361
128
181
357
169
334
Final R indices I >
R1 0.0601, wR2
R1 0.0485, wR2
R1 0.0360, wR2
R1 0.0792, wR2
R1 0.0576, wR2
R1 0.0336, wR2
2r(I)]
0.1411
0.1612
0.0781
0.1758
0.1554
0.2747
R indices (all data)
R1 0.1203, wR2
0.1744
R1 0.0567, wR2
0.2090
R1 0.0582, wR2
0.0870
R1 0.1155, wR2
0.2006
R1 0.0864, wR2
0.1745
R1 0.1205, wR2
0.0908
−3
˚
Max., min. Dq/e A
0.499, −0.332
1.722, −2.198
0.89, −0.89
1.313, −1.011
0.77, −1.08
0.89, −0.76
Goodness of fit on F2
1.044
1.229
1.031
1.069
1.074
1.05
104 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
˚
palladium complexes exhibit virtual coupling, and on this basis
6–15 are assumed to adopt trans-geometries. For the platinum
complexes, in addition to the appearance of the spectrum, the
(1.101(9) A) is shorter than the average for all crystallographically
˚
characterised trans-[RhCl(CO)(PR3)2] complexes (1.140(7) A)
which is consistent with the higher than typical m(CO) stretching
frequency observed for 1.
Examination of the data for 1 shows that there are two
intramolecular interactions of 3.253(8) and 3.332(8) A from
the rhodium centre to the cis fluorine atoms of each of the
perfluorovinyl groups (F3 and F6), which are significantly shorter
than the sum of the van der Waals radii (3.72 A). These
1
magnitude of the J(Pt–P) coupling constants (195Pt, I = 1/2,
33.8%) were used to determine the geometry of the isomers
formed. We note that the magnitude of this coupling constant
˚
i
=
=
increases in the order PCy2(CF CF2) < P Pr2(CF CF2) <
=
PPh(CF CF2)2 for the series of trans-[PtCl2P2] complexes.
˚
It is clear from the data in Table 1 that for the platinum(II)
complexes the position of the cis–trans equilibrium in solution
is finely balanced. Complexes of the larger phosphines e.g.
interactions are orientated above and below the metal centre
with F(3)–Rh–F(6) and F(3)–Rh–Cl(1) angles of 136.54(18)◦ and
67.82(14)◦ respectively, indicating considerable distortion from
an arrangement where the two fluorine atoms could be said
to distantly occupy the vacant octahedral sites. Additionally,
two short Rh · · · H interactions to ortho protons are indicated
=
PCy2(CF CF2) and/or larger halide ligands, such as iodide, result
exclusively in platinum complexes of trans-geometries in solution,
while for the sterically less demanding ligands the cis-isomer is
16
=
more likely to be observed, e.g. cis-[PtCl2{PEt2(CF CF2)}2].
˚
˚
For ligands of intermediate size a mixture of cis- and trans-
isomers is observed in solution. Because of these findings we were
interested in quantifying the steric demand of these ligands as
well as determining whether their solid state structures reflect the
solution phase data.
[Rh · · · H(9) 3.007 A, Rh · · · H(27) 3.068 A]. In the extended
structure of 1, molecules align in infinite stacks perpendicular
to the a direction, but with no particularly short contacts between
adjacent molecules.
Synthesis and characterisation of Pd(II) and Pt(II) complexes
Crystal structures of Pd(II) and Pt(II) complexes
The reaction of K2MX4 (M = Pd, Pt; X = Cl, Br, I) in aqueous
ethanolic solution with two equivalents of the perfluorovinyl-
containing ligands in all cases resulted in the formation of com-
Single crystals were successfully grown for the complexes
i
i
=
=
[PdCl2{P Pr2(CF CF2)}2], 9, [PdBr2{P Pr2(CF CF2)}2], 10,
=
=
=
plexes of the general formula [MX2{PRn(CF CF2)3−n}2] (except
[PdCl2{PCy2(CF CF2)}2], 12, [PdBr2{PPh(CF CF2)2}2] 14,
i
=
=
=
for the bulky PCy2(CF CF2) ligand for which only the chlorides
[PdI2{PPh(CF CF2)2}2] 15, [PtCl2{P Pr2(CF CF2)}2], 16,
i
i
= =
[PtBr2{P Pr2(CF CF2)}2], 17, [PtI2{P Pr2(CF CF2)}2] 18,
were prepared).
=
=
For all of the complexes NMR data was much as anticipated,
and this is summarised in Table 1. In each case the 31P NMR
resonance for the complex was shifted to higher frequency by 40–
50 ppm compared with that observed for the free ligand. All of the
[PtCl2{PCy2(CF CF2)}2], 19 and [PtBr2{PPh(CF CF2)2}2], 21.
The crystallographic data for these complexes are presented in
Tables 2 and 3 and ORTEP representations of their structures are
shown in Fig. 2 and 3.
i
=
=
Table 3 Crystallographic data for [PtX2{PR2(CF CF2)}2] (R = Pr, X = Cl, 16; Br, 17; I, 18; R = Cy, X = Cl, 19) and cis-[PtBr2{PPh(CF CF2)2}2], 21
16
17
18
19
21
Formula
C16H28Cl2F6P2Pt
662.3
Monoclinic
C16H28Br2F6P2Pt
751.23
Monoclinic
C16H28I2F6P2Pt
845.20
Orthorhombic
C28H44Cl2F6P2Pt
822.20
Triclinic
¯
P1
11.2760(2)
11.6583(2)
14.9767(3)
74.5780(10)
70.0010(10)
63.9810(10)
1646.86(5)
2
C20H10Br2F12P2Pt
895.13
Monoclinic
Formula weight
Crystal system
Space group
P21/c
P21/n
Pbca
P21/c
˚
a/A
8.1294 (9)
16.184 (7)
25.965 (8)
90
93.315 (15)
90
3410.4 (19)
4
293 (2)
9.7227 (3)
11.5780 (4)
10.7417 (4)
90
93.241 (2)
90
1207.25 (7)
2
293 (2)
12.6437 (16)
12.9891 (18)
14.5673 (19)
90
90
90
2392.4 (5)
8
203 (2)
11.3236 (3)
13.3972 (2)
16.7449 (2)
90
106.182 (2)
90
2439.63 (8)
4
293 (2)
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
3
˚
V/A
Z
T/K
150(2)
1.659
Dc/g cm−3
1.935
2.066
2.347
2.437
Crystal size/mm
0.15 × 0.15 × 0.20
0.15 × 0.15 × 0.07 0.25 × 0.20 × 0.20
0.07 × 01.8 × 0.18
0.10 × 0.10 × 0.20
l/mm−1
)
6.595
9.299
8.626
4.570
9.259
2h range/◦
2.96 → 49.98
6444
5986 (0.019)
4824
7.6 → 50.00
5.4 → 49.96
6.0 → 55.0
7530
7530 (0.085)
5104
4.0 → 50.00
4507
4276 (0.030)
3115
Total reflections
Unique reflections (Rint
Observed reflections [I > 2r(I)]
Parameters
10256
2102
)
2117 (0.030)
1842
125
2102
1713
132
379
355
334
Final R indices I > 2r(I)]
R1 0.0627, wR2
0.1670
R1 0.0314, wR2
0.0842
R1 0.0434, wR2
0.1078
R1 0.0531 wR2
0.1407
R1 0.0382, wR2
0.0622
R indices (all data)
R1 0.0806, wR2
0.1842
R1 0.0373, wR2
0.0887
R1 0.0549, wR2
0.1129
R1 0.0815 wR2
0.1607
R1 0.0712, wR2
0.0705
−3
˚
Max., min. Dq/e A
3.40, −4.30
1.287, −1.460
1.139, −1.313
−3.02, 3.04
0.947, −0.763
Goodness of fit on F2
1.039
1.067
1.101
1.09
1.022
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 105
©

View Article Online
Fig. 2 ORTEP representation of the structures of (a) 9, (b) 10, (c) 12, (d) 14 and (e) 15. Thermal ellipsoids are shown at the 30% level. Selected bond
◦
˚
lengths (A) and angles ( ) (other data are given in Table 4): (a) P–C1 1.810(6), P–C6 1.826(6), P–C3 1.837(6), F1–C1 1.363(7), F2–C2 1.324(7), F3–C2
1.303(9); Cl–Pd–P 91.23(6), C2–C1–F1 116.6(5), C2–C1–P 125.6(5), F1–C1–P 117.8(5), C1–C2–F3 125.4(6), C1–C2–F2 124.3(7), F3–C2–F2 110.3(6);
(b) C1–C2 1.279(6), C1–F1 1.377(4), C1–P 1.822(4), C2–F3 1.291(6), C2–F2 1.331(5), C3–P 1.845(4), C6–P 1.846(4); C2–C1–F1 115.3(4), C2–C1–P
127.4(3), F1–C1–P 117.2(3), C1–C2–F3 123.6(4), C1–C2–F2 124.7(5), F3–C2–F2 111.7(4), P Pd Br 90.67(2); (c) C1–C2 1.292(15), C1–F1 1.390(11), C1–P
1.807(9), C2–F3 1.294(14), C2–F2 1.330(12), C3–P 1.830(9), C9–P 1.839(9); C2–C1–F1 115.9(9), C2–C1–P1 126.2(9), F1–C1–P1 117.9(7), C1–C2–F3
124.4(10), C1–C2–F2 125.3(12), F2–C2–F3 110.3(10), Cl–Pd–P 91.98(7); (d) P–C1 1.802(10), P–C5 1.810(10), P–C3 1.826(11), C1–C2 1.293(17), C1–F1
1.357(13), C2–F3 1.263(16), C2–F2 1.329(13); P–Pd–Br 88.56(7), C10–C5–P 121.5(9), C6–C5–P 118.6(7), C2–C1–F1 116.8(10), C2–C1–P1 125.7(10),
F1–C1–P1 117.4(8), F3–C2–C1 126.3(11), F3–C2–F2 109.6(11), C1–C2–F2 124.1(14), C4–C3–F4 116.6(14), C4–C3–P 129.9(14), F4–C3–P1 113.4(8),
C3–C4–F6 122.7(16), C3–C4–F5 120(2), F6–C4–F5 117.0(14); (e) C1–C2 1.282(9), C1–F1 1.349(7), C1–P 1.810(6), C2–F3 1.306(8), C2–F2 1.307(8),
C3–C4 1.283(9), C3–F4 1.346(7), C3–P 1.825(6), C4–F6 1.304(8), C4–F5 1.322(8), C5–P1 1.809(5); C2–C1–F1 116.6(6), C2–C1–P 126.9(5), F1–C1–P
116.3(4), C1–C2–F3 124.8(6), C1–C2–F2 124.9(7), F3–C2–F2 110.3(6), C4–C3–F4 115.9(6), C4–C3–P1 129.4(5), F4–C3–P1 114.7(4), C3–C4–F6 126.2(6),
C3–C4–F5 124.0(7), F6–C4–F5 109.8(6).
Four of the palladium complexes, 9, 12, 14 and 15, crystallize
in the triclinic P1 space group, while 10 is monoclinic (P21/n).
previously reported perfluorovinyl phosphine complexes.14,16,17 The
longest of the three C–F bonds is that of the a-fluorine, whilst
the bond to the cis-fluorine is slightly shorter than that to
the trans-fluorine. The presence of intramolecular metal–fluorine
¯
Complexes 9, 10 and 15 are found to possess a single unique
molecule, while 12 and 14 both contain two molecules. In the
latter complex one of the molecules shows disorder of a single
perfluorovinyl group, and this was modelled during the analysis
using two sites of equal occupancy.
˚
interactions of ca. 3.4 A, less than the sum of the van der Waals
˚
radii of palladium and fluorine (3.77 A), are observed from the
cis-fluorine atom to the palladium atom, similar to that found
in the rhodium complex, 1, (see Table 4). It is noteworthy that
in 14 and 15 a M · · · F interaction is observed to only one of
the two perfluorovinyl groups of each phosphine ligand. Also,
The X-ray crystallographic data confirms the interpretation of
1
the 31P{ H} NMR data, in that all of the palladium complexes
adopt a trans-geometry. The Pd atoms are located on a centre
˚
=
of symmetry. The Pd–P distances range from ca. 2.306 A for the
for both complexes the Pd–P–Cpfv bond angle for the CF CF2
PPhpfv2-containing complexes to 2.3331(8) A for the P Pr2pfv
group involved in this interaction is smaller (114.4(4) cf . 116.3(5)◦
i
˚
complex, see Table 4. In each case these distances are slightly
shorter than the average Pd–P distance for all trans-[PdX2(PR3)2]
complexes containing simple monodentate phosphine ligands in
the CCDC database,28 but are similar to Pd–P distances ob-
served in other palladium complexes containing organofluorine-
and 116.5(2) cf . 120.4(2)◦ respectively) than that observed for the
second one not involved in such an interaction.
i
=
The extended structure of [PdCl2{P Pr2(CF CF2)}2], 9, shows
that molecules align in infinite stacks along the c direc-
tion, although no particularly short interactions are observed.
i
=
substituted phosphines, for example, trans-[PdCl2{P(C6F5)3}2],
[PdBr2{P Pr2(CF CF2)}2], 10, packs in chains of infinite stacks
29
˚
˚
d(Pd–P) = 2.3051(12) A and Pd–Cl = 2.2907(10) A.
along the b cell dimension (see Fig. 4) with both perfluorovinyl
=
The C C and C–F distances of the perfluorovinyl fragment in
the palladium complexes are consistent with those found in the
groups overlapping with those of adjacent molecules, albeit at
˚
a distance of ca. 6 A. Intermolecular hydrogen bonds are also
˚
crystal structure of 1, and are similar to those observed for other
observed with d(H(6) · · · Br(1)) = 2.88(4) A.
106 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
Fig. 3 ORTEP representation of the structures of (a) 17, (b) 18, (c) 19, and (d) 20. Thermal ellipsoids are shown at the 30% level. Selected bond
◦
˚
lengths (A) and angles ( ) (other data are given in Table 4): (a) C1–C2 1.288(9), C1–F1 1.377(7), C1–P 1.820(6), C2–F3 1.298(9), C2–F2 1.334(8),
C3–P 1.840(6), C6–P 1.847(7); C2–C1–F1 115.1(6), C2–C1–P 127.6(5), F1–C1–P 117.2(4), C1–C2–F3 123.8(7), C1–C2–F2 124.5(7), F3–C2–F2 111.7(6),
P–Pt–Br 89.51(4); (b) P–C1 1.818(8), P–C6 1.841(9), P–C3 1.842(8), F1–C1 1.361(10), F2–C2 1.312(11), F3–C2 1.318(10), C1–C2 1.297(13); P–Pt–I
91.14(5), C2–C1–F1 114.9(7), C2–C1–P 128.0(7), F1–C1–P 117.0(6), C1–C2–F2 126.0(9), C1–C2–F3 124.1(8), F2–C2–F3 109.9(8), C5–C3–P 111.7(6),
C4–C3–P 110.3(6), C7–C6–P 111.4(7), C8–C6–P 110.8(7); (c) C1–C2 1.307(12), C1–F1 1.363(10), C1–P 1.822(8), C2–F2 1.288(11), C2–F3 1.328(9), C3–P
1.845(7), C9–P 1.836(8); C2–C1–F1 116.4(8), C2–C1–P1 125.4(7), F1–C1–P 118.1(6), F2–C2–C1 125.1(8), F2–C2–F3 111.5(8), C1–C2–F3 123.4(10), Cl
Pt P 91.74(6); (d) P1–C9 1.790(8), P1–C3 1.813(8), P1–C1 1.817(8), F1–C1 1.330(9), F2–C2 1.306(9), F3–C2 1.308(10), F4–C9 1.359(8), F5–C10 1.297(8),
F6–C10 1.316(9), P2–C13 1.798(8), P2–C15 1.810(8), P2–C11 1.812(8), F7–C11 1.351(9) F8–C12 1.297(9), F9–C12 1.327(10), F10–C13 1.370(8), F11–C14
1.326(10), F12–C14 1.276(11), C1–C2 1.313(11), C9–C10 1.301(10), C11–C12 1.301(11), C13–C14 1.301(12); P1–Pt–P2 99.22(7), P1–Pt–Br1 90.28(6),
P2–Pt–Br1 170.36(6), P1–Pt–Br2 176.04(6), P2–Pt–Br2 83.58(6), Br1–Pt–Br2 86.85(3), C2–C1–F1 117.4(7), C2–C1–P1 127.7(7), F1–C1–P1 114.7(6),
F2–C2–F3 111.3(7), F2–C2–C1 123.9(9), F3–C2–C1 124.8(8), C4–C3–P1 114.7(6), C10–C9–F4 114.7(7), C10–C9–P1 128.9(6), F4–C9–P1 116.4(5),
F5–C10–C9 124.8(8), F5–C10–F6 110.9(7), C9–C10–F6 124.4(7), C12–C11–F7 114.8(8), C12–C11–P2 133.0(7), F7–C11–P2 112.0(5), F8–C12–C11
125.4(9), F8–C12–F9 110.8(7), C11–C12–F9 123.6(8), C14–C13–F10 116.5(8), C14–C13–P2 130.6(7), F10–C13–P2 112.3(6), F12–C14–C13 126.4(9),
F12–C14–F11 111.3(8), C13–C14–F11 122.3(9).
The extended structures of 14 and 15 both exhibit stacks of
molecules in the c direction which show alignment between the
phenyl groups of adjacent molecules. In 14 no particularly short
arene–arene distances are apparent, but in 15 the arene rings
are much closer with the centroid to centroid distance being
˚
4.085 A.
In addition to the X-ray data for the palladium complexes, solid
state structures of five of the platinum(II) complexes 16–19 and 21
were also obtained (Table 3). Two of these are analogues of the
=
palladium-containing complexes, viz. [MCl2{PCy2(CF CF2)}2]
i
=
19 (M = Pt) and 12 (M = Pd) and [MBr2{P Pr2(CF CF2)}2]
17 (M = Pt) and 10 (M = Pd). In each case both complexes
of the same ligand are isostructural. Complexes 17–19 all ex-
i
˚
=
Fig. 4 Packing diagram for [PdBr2{P Pr2(CF CF2)}2], 10 showing the
hibit trans-geometries with Pt–P distances between 2.2985(19) A
i
stacking of perfluorovinyl groups from adjacent molecules.
˚
=
=
[for PCy2(CF CF2)] and 2.3143(14) A for P Pr2(CF CF2).
These distances, and the platinum–halide distances, are com-
parable with those reported for other structurally characterised
trans-[PtX2(PR3)2] complexes in the Cambridge Crystallographic
Database, where R contains electron-withdrawing substituents.28
Intramolecular M · · · F interactions, similar to those observed
for the rhodium and palladium systems, are observed in the
trans square planar complexes and these distances are listed in
Table 4. Interestingly, not all of the cis-complexes exhibit the same
interaction.
Complex 12 also stacks along the crystallographic b direction
with the perfluorovinyl groups overlapping similarly to that
observed in 10. A number of intermolecular hydrogen bonding
interactions are also observed between protons of the cyclohexyl
fragment in one molecule and the chloride ligands (average dis-
˚
tance 2.77 A) and the trans-fluorine of the pfv group, d(H · · · F)av =
˚
2.50 A of another.
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 107
©

View Article Online
Once again the extended structures of these complexes are
largely dominated by interactions between protons and the metal-
bound halide ligands, as well as to the cis-fluorines of the
perfluorovinyl group, to generate stacks of molecules.
˚
Thus, for example, in 19, Cl · · · H distances of 2.754 and 2.772 A
˚
are observed along with F · · · H interactions of 2.516 A. However,
in contrast to most of the other complexes studied here, the iodide
i
=
complex of P Pr2(CF CF2), 18, displays no hydrogen interactions
less than the sum of the van der Waals radii, with either the
iodide or any perfluorovinyl fluorine atom. Instead, alignment
of molecules occurs to generate alternate fluorinated and non-
fluorinated layers, as is shown in Fig. 5.
i
=
Fig. 5 Packing diagram for [PtI2{P Pr2(CF CF2)}2], 18.
The solid-state structure of complex 21 (which in solution shows
the presence of both cis- and trans-isomers) shows exclusively the
cis-isomer. The molecule exhibits slight asymmetry in the Pt–
P and Pt–Br bond lengths, with average values being 2.240(2)
˚
and 2.4493(9) A respectively. Both the Pt–P and Pt–Br distances
are somewhat shorter than typical values for cis-[PtX2(PR3)2]
systems, but are comparable with Pt–P bond lengths observed
for complexes containing other perfluoro-organo substituted
phosphines, such as cis-[PtCl2{PEt(p-C6F13C6H4)2}2].30 However,
the Pt–P distances are still significantly longer than those observed
in platinum(II) complexes of P–F containing phosphines, such as
cis-[PtCl2{PF2(o-OMeC6H4}2],31 (Pt–P = 2.180(5)/2.181(4) A), or
˚
in tertiary phosphite complexes such as cis-[PtCl2{P(OMe)3}2],32
˚
(Pt–P = 2.192(3)/2.155(3) A).
Unlike the trans-complexes a single intramolecular Pt · · · F
˚
interaction is observed (3.243(4) A), but, in common with the
other complexes, intermolecular H · · · F and H · · · Br interactions
less than the sum of the van der Waals radii are apparent which
result in stacks of molecules aligned along the a crystallographic
direction. When viewed from this direction aggregation of the
halogen-containing parts of the molecules is apparent, see Fig. 6.
The most interesting of the structures determined was that for
i
=
[PtCl2{P Pr2(CF CF2)}2], 16, which revealed a highly unusual
mixture of cis- and trans-isomers co-crystallised in the same unit
cell, see Fig. 7. The trans-isomers are located at the corners of
108 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
for cis-[PtX2L2] complexes. The Pt–P bonds in the cis isomer are
˚
shorter than the Pt–P bonds in the trans isomer [2.290(3) A],
whilst the reverse trend is seen for the Pt–Cl bonds, Table 3. These
trends are anticipated based upon the relative trans influence of
phosphine and chloride ligands, (P > Cl). The Pt–P bond in cis-
i
=
[PtCl2{P Pr2(CF CF2)}2] is comparable to that observed in 21 but
slightly longer than that observed in the previously reported cis-
14
=
[PtCl2{PPh2(CF CF2)}2] complex. The Pt–P and Pt–Cl bond
˚
lengths observed for the trans-isomer of 16 [Pt–P: 2.290(3) A; Pt–
˚
Cl: 2.292(3) A] are both shorter than the values reported for trans-
i
33
˚
˚
[PtCl2(P Pr3)2], where Pt–P = 2.339(1) A, and Pt–Cl = 2.303(1) A,
but once again are comparable to those distances observed
for similar complexes containing perfluoro-organo substituted
phosphines, such as 17, 18 and trans-[PtCl2{P(C6F5)3}2].34 Both
isomers of 16 display the usual variations in C–F distances in that
the a-C–F bond is the longest. Differences between the C–F bonds
to the cis- and trans-fluorine atoms in both isomers are small, and
not significant within the experimental error.
=
Fig. 6 Packing diagram for [PtBr2{PPh(CF CF2)2}2], 21.
The cis-isomer displays no intramolecular metal–fluorine in-
teractions, unlike the situation observed for nearly all the other
structures reported here, but it does display Pt · · · H interactions
to protons of the isopropyl fragment. In contrast a short Pt · · · F
˚
interaction of 3.486(10) A is observed for the trans-isomer (cf.
˚
sum of the van der Waals radii of platinum and fluorine of 3.77 A),
along with three short Pt · · · H interactions. Once again a reduction
in the M–P–C bond angle is observed to coincide with the presence
of the M · · · F interaction (Pt–P–C in the trans-isomer = 114.5(4)◦
cf . 117.5(4) and 118.1(4)◦ for the cis-analogue).
i
=
The cis/trans-arrangement of [PtCl2{P Pr2(CF CF2)}2], 16,
i
=
Fig. 7 ORTEP representation of [PtCl2{P Pr2(CF CF2)}2], 16. Thermal
results in the fluorine-containing substituents congregating to-
gether to form a series of isolated fluorous domains, as shown in
Fig. 9. Two short intermolecular F · · · F contacts are observed,
ellipsoids are set to 50% and hydrogens have been removed for clarity.
the unit cell, and on the top and bottom face, whilst cis-isomers
are located in-between, resulting in the unit cell containing 4 cis
and 2 trans molecules, giving a cis : trans ratio of 2 : 1, as shown in
Fig. 8.
˚
˚
[F(5) · · · F(8): 2.848(12) A; F(2) · · · F(7): 2.866(14) A, which are
˚
less than double the van der Waals radius of fluorine, 2.94 A].
The cis-isomers also display a short intermolecular H(8A) · · · Cl(2)
˚
˚
interaction of 2.763 A, (cf. sum of the van der Waals radii of 2.95 A)
Fig.
8
=
Representation of the unit cell of cis/trans- [PtCl2{PiPr2-
(CF CF2)}2], 16, showing the relative positions of the cis (black) and
trans (red) isomers. Hydrogen atoms have been removed for clarity.
The cis isomer displays deviation from an ideal square planar
geometry, with P–Pt–Cl angles of 170.86(13)◦ and 171.18(12)◦,
˚
and slight asymmetry in the Pt–P [2.243(3) and 2.246(3) A] and
Fig. 9 Space filling representation of co-crystallized cis- and trans-
i
˚
=
Pt–Cl [2.326(3) and 2.336(3) A] distances, as is typically observed
[PtCl2{P Pr2(CF CF2)}2], 16, showing the fluorous domains.
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 109
©

View Article Online
ꢀ
from the metal bound chloride, akin to the interaction observed
S4 value calculated based on the M–P–C and C–P–C bond angles
i
ꢀ
ꢀ
=
for [PdBr2{P Pr2(CF CF2)}2], 10.
(S4 = [r(M–P–C) − r(C–P–C)] listed in Table 4. The S4 value de-
The observation of co-crystallized cis- and trans-isomers within
the same unit cell is highly unusual. Multi-metallic systems,
particularly based on rings or clusters, are known in which
different metal centres exhibit different coordination geometries.
For example, the bidentate stibine35 and arsine36 ligands of the type
Ph2ECH2EPh2 (E = As, Sb) can form bridged bimetallic systems
with platinum and palladium in which one metal adopts a cis-
geometry and the other trans. But, to the best of our knowledge,
there is only one other analogous example of the phenomenon
we observe here. [PtCl2{P(C6H4C6F13-4)3}2] was found to adopt a
similar packing arrangement to give a cis : trans ratio of 2 : 1.37
In that complex the long fluorous chains are believed to be
responsible for the packing, and the solution phase also contained
both cis- and trans-isomers. In 16 it appears unlikely that a
C2F3 unit is sufficient to give rise to fluorophobic/fluorophilic
interactions, although it is clear that in the extended structure,
as shown in the space-filling representation in Fig. 9, that the
fluorovinyl groups are found to aggregate.
termined is sensitive to the halide and the geometry of the complex.
For example, the calculated S4 values for P Pr2(CF CF2) vary
ꢀ
i
=
◦
◦
i
=
from 29.7 in trans-[PtCl2{P Pr2(CF CF2)}2], 16, to 38.8 in trans-
i
=
[PtI2{P Pr2(CF CF2)}2], 18, whilst the cis-isomer of 16 yields a
value of 34.7◦ which lies between these two limits. Essentially, a
ꢀ
lower S4 is observed in complexes where the ligand participates
in a less sterically congested coordination sphere, and can thus
expand to fill the available space. This is further illustrated by the
ꢀ
i
=
S4 value obtained from the crystal structure of SP Pr2(CF CF2)
which is 26.4◦.9 The Tolman cone angles also show some variation
from complex to complex. In order to allow sensible comparison
of the determined values, we have taken the average of data for
monomeric square-planar complexes only, and ignored any ligand
which exhibits disorder. These values, along with electronic data,
for our ligands and some related systems are presented in Table 5.
ꢀ
Both the Tolman cone angle and the S4 values give the same
order for the size of the perfluorovinyl-containing phosphines,
PEt2pfv < PPhpfv2 < PPh2pfv = PiPr2pfv < PCy2pfv. The ordering
The observation in the solid state of both isomers is in contrast
with the solution phase where 16 exists as the trans-isomer alone,
of the phenyl-containing ligands is consistent with that calculated
ꢀ
=
by Cundari et al., with theoretical S4 values for PPh2(CF CF2)
◦
1
6
on the basis of the 31P{ H} NMR data, vide supra. The co-
and PPh(CF CF2)2 of 39 and 49 respectively. The values that
we obtain from the X-ray data are smaller, meaning that the
=
crystallisation of both isomers appears to be a phenomenon
arising from crystal growth, as re-dissolution of the crystals results
ligands are larger than calculated, but of the same order. Thus,
1
in a 31P{ H} NMR spectrum consistent with only the presence
PPh(CF CF2)2 is sterically less demanding than PPh2(CF CF2).
=
=
i
=
of the trans-isomer, as was obtained for the powder prior to
It is noteworthy that the Tolman cone angle for P Pr2(CF CF2)
crystallisation.
(165◦) lies between those of PiPr3 (160◦) and PCy3 (170◦), which
suggests that the perfluorovinyl group possesses a considerable
steric footprint. However its steric demand is not as great as that
of the C6F5 substituent. It has been suggested recently that this is
A comparison of steric and electronic properties
=
Many of the complexes reported here represent the first examples
of structurally characterised coordination compounds of the
specific perfluorovinyl phosphines. It is therefore appropriate
to use these data to obtain estimates of the steric demand of
these ligands, to compliment the electronic data derived from the
rhodium complexes. For all of the reported complexes the Tolman
cone angle has been derived using the STERIC program38 and the
the reason why PPh(CF CF2)2 successfully cleaves [Cp*RhCl(l-
Cl)]2 to form complexes yet PPh(C6F5)2 does not.40
It is clear from the data in Table 5 that from an electronic
standpoint the phosphine ligands containing one perfluorovinyl-
group and two donating fragments lie mid-way between traditional
phosphines and phosphites in their electronic properties. Further-
more the exact donating power and steric demand of the ligand
Table 5 Electronic and steric parameters for selected phosphorus(III) ligands
◦
m(CO)a/cm−1
Tolman cone angleb/◦
S4 /
ꢀ
c
P(III) ligand
PiPr3
PPh3
PEt2(CF CF2)
1950g
1965g
1981
160g
35d
35d
44
138g
e
=
152
[142, 157, 157, 154]
165
[168, 166, 160, 159, 169, 166, 165]
169
[168, 170, 168, 170]
163
[164, 162, 164, 160]
161
[45, 66, 30, 37]
34
[32, 35, 35, 35, 30, 35, 39]
29
i
=
P Pr2(CF CF2)
1981
1979
1989
2002
=
PCy2(CF CF2)
[31, 23, 34, 29]
f
34, 39d
=
PPh2(CF CF2)
[38, 38, 36,25]
39, 49d
=
PPh(CF CF2)2
[169, 163, 161, 150]
[44, 36, 38, 37]
PPh2(C6F5)
PPh(C6F5)2
P(OMe)3
1982g
1996g
2006g
2016g
158g
171g
107g
128g
38d
38d
63d
P(OPh)3
76d
a For the complex [Rh(CO)Cl(P)2]. b Average and [observed] values, see text. c As for (b). d Calculated value taken from ref. 6. e Data also from ref. 16.
f Data also from ref. 14. g Data from ref. 2, 27 or 39.
110 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
can be tailored by altering its composition and the identity of the
R-groups. In this respect these ligands are like other phosphines
containing perfluorinated groups, but there are, however, subtle
differences, in particular the perfluorovinyl group appears to have
a smaller steric footprint than a pentafluorophenyl group yet has
a greater electronic influence.
refined against F2 using SHELXTL41 or SHELX-97.42 All non-H
atoms were modelled with anisotropic displacement parameters,
H-atoms were placed in idealised positions and refined with
isotropic thermal parameters. The computer packages PLUTON43
and MERCURY44 were used to investigate the extended structures
and to produce graphical representations used in the figures.
General method of synthesis for rhodium(I) complexes 1–5
Conclusion
To a solution of one equivalent of [RhCl(CO)2]2 dissolved
in degassed dichloromethane (20 cm3) four equivalents of the
appropriate phosphine dissolved in dichloromethane (20 cm3) was
added dropwise. Immediate effervescence was observed and the
solution became yellow. The solution was stirred under an argon
atmosphere at room temperature for 1 h, after which time the
solvent was removed. The resulting residue was washed with 2 ×
10 cm3 portions of hexane, filtered and dried in vacuo to yield the
rhodium(I) complexes 1 to 5.
We report a systematic study of the coordination chemistry of a
series of perfluorovinyl-containing phosphine ligands in square-
planar Rh(I), Pd(II) and Pt(II) systems. From these we have been
able to quantify both the electronic and steric properties of these
ligands. We find that electronically the ligands approximate to
traditional phosphites, whilst their steric demand is significantly
greater. As such they fill one of the previously identified voids in the
stereoelectronic profile of P(III) ligands.6 The solid state structures
of a number of the complexes have been obtained. For the smaller
phosphines cis-geometries are observed, whilst trans-isomers are
observed for the larger phosphines. Nearly all complexes exhibit
intramolecular M · · · F interactions, as well as intermolecular
hydrogen bonding. In some other complexes the formation of
fluorous domains within the solid state structure occurs instead.
The balance between these effects appears to be very fine, indeed
it would appear that for the perfluorovinyl-containing phosphines
of intermediate size there is little differentiation between the cis-
and trans-isomers. This is attributed to a small energy difference
between the two isomers and is supported by the observation that
trans-[RhCl(CO){PPh2(CF CF2)}2], 1. 19F NMR: d: −82.4
=
(trans) [dd, 2J(FF) = 34 Hz, 3J(FF) = 32 Hz], −96.0 (cis)
2
3
[dd, J(FF) = 34 Hz, J(FF) = 119 Hz], −176.5 (gem) [ddvt,
1/2|2J(PF) + 4J(PF)| = 15 Hz, 3J(FF) = 32 Hz, 3J(FF) =
119 Hz]. Raman (cm−1): 310 m(Rh–Cl). IR (Nujol, cm−1): 1989
=
m(C≡O), 1732 m(C C), 1314, 1146, 1051 m(C–F).
trans-[RhCl(CO){PEt2(CF CF2)}2], 2. 19F NMR: d: −84.1
=
(trans) [dd, 2J(FF) = 47 Hz, 3J(FF) = 32 Hz], −102.1 (cis)
2
3
[dd, J(FF) = 47 Hz, J(FF) = 120 Hz], −182.1 (gem) [ddvt,
1/2|2J(PF) + 4J(PF)| = 17 Hz, 3J(FF) = 32 Hz, 3J(FF) =
120 Hz]. Raman (cm−1): 306 m(Rh–Cl). IR (Nujol, cm−1): 1981
secondary factors are able to tip the balance from one-isomer to
i
=
the other to the point where [PtCl2{P Pr2(CF CF2)}2] crystallises,
=
m(C≡O), 1736 m(C C), 1314, 1146, 1030 m(C–F).
unusually, as a cis : trans mixture which allows for the formation
trans-[RhCl(CO){P Pr2(CF CF2)}2], 3. 19F NMR: d: −83.7
i
of localised fluorous domains within the crystal.
=
(trans) [dd, 2J(FF) = 45 Hz, 3J(FF) = 32 Hz], −100.2 (cis)
2
3
[dd, J(FF) = 45 Hz, J(FF) = 119 Hz], −177.7 (gem) [ddvt,
1/2|2J(PF) + 4J(PF)| = 12 Hz, 3J(FF) = 32 Hz, 3J(FF) =
119 Hz]. Raman (cm−1): 307 m(Rh–Cl). IR (Nujol, cm−1): 1981
Experimental
All ligand synthesis reactions were carried out under an inert
atmosphere of argon or dinitrogen in flame dried glassware
as previously described.14,16,17 [RhCl(CO)2]2 (Aldrich), K2PdCl4
and K2PtCl4 (Johnson Matthey), were used as supplied after
=
m(C≡O), 1730 m(C C), 1308, 1148, 1051 m(C–F).
trans-[RhCl(CO){PCy2(CF CF2)}2], 4. 19F NMR: d: −84.3
=
(trans) [dd, 2J(FF) = 45 Hz, 3J(FF) = 33 Hz], −100.5 (cis)
1
verification of their purity. 19F and 31P{ H} NMR spectra were
2
3
[dd, J(FF) = 45 Hz, J(FF) = 120 Hz], −177.0 (gem) [ddvt,
recorded on a Bruker DPX200 spectrometer operating at 188.310
1/2|2J(PF) + 4J(PF)| = 12 Hz, 3J(FF) = 33 Hz, 3J(FF) =
1
and 81.014 MHz respectively. 1H and 13C{ H} NMR spectra were
−1
=
120 Hz]. IR (Nujol, cm ): 1979 m(C≡O), 1732 m(C C), 1307,
recorded on a Bruker DPX300 spectrometer operating at 300.14
and 75.38 MHz. All samples were recorded as CDCl3 solutions
and peak positions are quoted relative to external CFCl3, 85%
H3PO4 and TMS using the high frequency positive convention.
Infrared spectra were recorded as Nujol mulls of samples held
between KBr discs, and Raman spectra in glass capillaries, on
a Nicolet-Nexus combined FT-IR/FT-Raman spectrometer with
OMNIC 5 software. Elemental analyses were performed by the
UMIST Chemistry Department microanalytical service.
1144, 1047 m(C–F).
trans-[RhCl(CO){PPh(CF CF2)2}2], 5. 19F NMR: d: −79.4
=
(trans) [dd, 2J(FF) = 32 Hz, 3J(FF) = 33 Hz], −96.1 (cis)
2
3
[dd, J(FF) = 32 Hz, J(FF) = 120 Hz], −178.6 (gem) [ddvt,
1/2|2J(PF) + 4J(PF)| = 19 Hz, 3J(FF) = 33 Hz, 3J(FF) =
120 Hz]. Raman (cm−1): 307 m(Rh–Cl). IR (Nujol, cm−1): 2002
=
m(C≡O), 1720 m(C C), 1310, 1156, 1051 m(C–F).
General method of synthesis for palladium(II) and platinum(II)
complexes 6–22
X-Ray crystallography
Details of the structure analyses carried out on compounds 1, 9, 10,
12, 14–19 and 21 are summarised in Tables 2 and 3. Measurements
for the complexes were made on crystals prepared by slow solvent
evaporation on a Rigaku AFC6S or Nonius MAC3 CAD4 diffrac-
tometer. X-Ray structural data solution was by direct methods and
One equivalent of K2PdCl4 or K2PtCl4 dissolved in water (10 cm3)
was added to a stirred solution of two equivalents of the appro-
priate perfluorovinylphosphine dissolved in ethanol (10 cm3). The
mixture was stirred for 15 min after which time the desired product
precipitated out. This was filtered off, washed with a little water
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 111
©

View Article Online
i
trans-[PdI2{P Pr2(CF CF2)}2], 11. 19F NMR: d: −85.6 (trans)
=
and dried under vacuum for 1 h. The bromo and iodo-analogues
were prepared by the reaction of the appropriate tetrachloro-
palladate or platinate salt with an excess of aqueous NaBr/HBr
or KI solution respectively, followed by gentle warming for 10 min
until the colour of the solution deepens. The tetrabromo/tetraiodo
palladate/platinate salts were then reacted with two equivalents
of phosphine as described above.
[dd, 2J(FF) = 49 Hz, 3J(FF) = 32 Hz], −97.1 (cis) [dd, 2J(FF) =
49 Hz, J(FF) = 116 Hz], −175.0 (gem) [ddvt, 1/2|2J(PF) +
3
4J(PF)| = 14 Hz, J(FF) = 32 Hz, J(FF) = 116 Hz]. Raman
3
3
−1
−1
=
(cm ): 137 m(Pd–I). IR (Nujol, cm ): 1738 m(C C), 1304, 1157,
1028 m(C–F).
trans-[PdCl2{PCy2(CF CF2)}2], 12. 19F NMR: d: −83.9
=
trans-[PdCl2{PPh2(CF CF2)}2], 6. 19F NMR: d: −82.1 (trans)
(trans) [dd, 2J(FF) = 45 Hz, 3J(FF) = 32 Hz], −97.9 (cis)
=
2
3
3
2
3
[dd, J(FF) = 37, J(FF) = 33], −95.9 (cis) [dd, J(FF) = 119,
[dd, J(FF) = 45 Hz, J(FF) = 118 Hz], −181.7 (gem) [ddvt,
1/2|2J(PF) + 4J(PF)| = 12 Hz, 3J(FF) = 32 Hz, 3J(FF) =
118 Hz]. Raman (cm−1): 302 m(Pd–Cl). IR (Nujol, cm−1): 1738
3
3
2J(FF) = 37], −177.7 (gem) [ddvt, J(FF) = 119, J(FF) = 33,
4
1
1/2|2J(PF) + J(PF)| = 17]. H NMR (CDCl3): d: 7.45–7.59
1
[m, 12H, Ar], 7.72–7.84 [m, 8H, Ar]. 13C{ H} NMR (CDCl3): d:
=
m(C C), 1308, 1152, 1047 m(C–F).
1
1
3
=
123.1 [CF CF2, dvtdd, J(CF) = 265.6, 1/2| J(PC) + J(PC)| =
trans-[PdCl2{PPh(CF CF2)2}2], 13. 19F NMR: d: −78.1
3
46.4, 2J(CF) = 31.9, 14.5], 125.1 [Ci, vt, 1/2|1J(PC) + J(PC)| =
=
(trans) [dd, 3J(FF) = 33, 2J(FF) = 31], −95.1 (cis) [dd, 3J(FF) =
5
27.0], 129.0 [Cm, vt, 1/2|3J(PC) + J(PC)| = 5.8], 132.3 [CP, s],
2
3
3
2
4
118, J(FF) = 31], −180.1 (gem) [ddvt, J(FF) = 118, J(FF) =
=
135.2 [Co, vt, 1/2| J(PC) + J(PC)| = 6.8], 159.6 [CF CF2,
dddvt, 1J(CF) = 306.1, 290.7, 2J(CF) = 40.6, 1/2|2J(PC) +
4J(PC)| = 13.5]. Raman (cm−1): 307 m(Pd–Cl). IR (Nujol, cm−1):
33, 1/2|2J(PF) + J(PF)| = 18]. H NMR: d: 7.58 [m, 4H, Ar],
4
1
7.65 [m, 2H, Ar], 7.93 [m, 4H, Ar]. 13C{ H} NMR: d: 118.9 [Ci, vt,
1
1
3
1
=
1/2| J(PC) + J(PC)| = 29.9], 119.6 [CF CF2, dvtdd, J(CF) =
=
1732 m(C C), 1314, 1150, 1051 m(C–F).
265.6, 1/2|1J(PC) + J(PC)| = 35.8, 2J(CF) = 31.9, 14.5], 129.6
3
trans-[PdBr2{PPh2(CF CF2)}2], 7. 19F NMR: d: −83.0 (trans)
[Cm, vt, 1/2|3J(PC) + J(PC)| = 6.8], 133.8 [CP, s], 135.5 [Co, vt,
5
=
2
3
3
4
1/2|2J(PC) + J(PC)| = 7.7], 159.6 [CF≡CF2, dddvt, 1J(CF) =
[dd, J(FF) = 37, J(FF) = 31], −95.0 (cis) [dd, J(FF) = 118,
3
3
2J(FF) = 37], −176.2 (gem) [ddvt, J(FF) = 118, J(FF) = 31,
302.6, 292.6, 2J(CF) = 39.6, 1/2|2J(PC) + 4J(PC)| = 15.5].
4
1
−1
−1
1/2|2J(PF) + J(PF)| = 17]. H NMR: d: 7.43–7.58 [m, 12H,
=
Raman (cm ): 318 m(Pd–Cl). IR (Nujol, cm ): 1732 m(C C),
1312, 1159, 1055 m(C–F).
13
1
=
Ar], 7.77–7.90 [m, 8H, Ar]. C{ H} NMR: d: 124.7 [CF CF2,
3
dvtdd, 1J(CF) = 265.6, 1/2|1J(PC) + J(PC)| = 45.4, 2J(CF) =
trans-[PdBr2{PPh(CF CF2)2}2], 14. 19F NMR: d: −78.8
3
31.9, 15.5], 126.3 [Ci, vt, 1/2|1J(PC) + J(PC)| = 28.0], 128.8
=
(trans) [dd, 3J(FF) = 33, 2J(FF) = 33], −94.6 (cis) [dd, 3J(FF) =
5
[Cm, vt, 1/2|3J(PC) + J(PC)| = 5.8], 132.2 [CP, s], 135.4 [Co, vt,
2
3
3
2
4
1
118, J(FF) = 33], −178.6 (gem) [ddvt, J(FF) = 118, J(FF) =
=
1/2| J(PC) + J(PC)| = 6.8], 159.1 [CF CF2, dddvt, J(CF) =
33, 1/2|2J(PF) + J(PF)| = 17]. H NMR: d: 7.56 [m, 4H, Ar],
4
1
306.1, 289.7, 2J(CF) = 41.5, 1/2|2J(PC) + 4J(PC)| = 13.5].
7.64 [m, 2H, Ar], 7.99 [m, 4H, Ar]. 13C{ H} NMR: d: 120.0 [Ci, vt,
1
−1
−1
=
Raman (cm ): 191 m(Pd–Br). IR (Nujol, cm ): 1732 m(C C),
1309, 1167, 1051 m(C–F).
1/2|1J(PC) + J(PC)| = 30.9], 120.8 [CF≡CF2, dvtdd, 1J(CF) =
3
265.6, 1/2|1J(PC) + J(PC)| = 49.2, 2J(CF) = 33.8, 13.5], 129.4
3
trans-[PdI2{PPh2(CF CF2)}2], 8. 19F NMR: d: −83.9 (trans)
[Cm, vt, 1/2|3J(PC) + J(PC)| = 6.8], 133.7 [CP, s], 135.9 [Co, vt,
5
=
2
3
3
2
4
1
=
[dd, J(FF) = 37, J(FF) = 31], −93.8 (cis) [dd, J(FF) = 119,
1/2| J(PC) + J(PC)| = 7.8], 159.3 [CF CF2, dddvt, J(CF) =
3
3
2J(FF) = 37], −173.3 (gem) [ddvt, J(FF) = 119, J(FF) = 31,
308.1, 291.6, 2J(CF) = 38.6, 1/2|2J(PC) + 4J(PC)| = 14.5].
4
1
−1
−1
1/2|2J(PF) + J(PF)| = 16]. H NMR: d: 7.43–7.56 [m, 12H,
Raman (cm ): 199 m(Pd–Br). IR (Nujol, cm ): 1728 m(C C),
1314, 1159, 1053 m(C–F).
=
1
Ar], 7.70–7.80 [m, 8H, Ar]. 13C{ H} NMR: d: 128.1 [CF≡CF2,
3
dvtdd, 1J(CF) = 266.6, 1/2|1J(PC) + J(PC)| = 46.4, 2J(CF) =
trans-[PdI2{PPh(CF CF2)2}2], 15. 19F NMR: d: −79.6 (trans)
3
=
32.9, 13.5], 129.1 [Ci, vt, 1/2|1J(PC) + J(PC)| = 29.0], 128.6
2
3
3
5
[Cm, vt, 1/2|3J(PC) + J(PC)| = 5.8], 132.0 [CP, s], 135.3 [Co, vt,
[dd, J(FF) = 33, J(FF) = 32], −93.6 (cis) [dd, J(FF) = 118,
2J(FF) = 33], −176.1 (gem) [ddvt, J(FF) = 118, J(FF) = 32,
3
3
2
4
1
=
1/2| J(PC) + J(PC)| = 5.8], 158.3 [CF CF2, dddvt, J(CF) =
4
1
1/2|2J(PF) + J(PF)| = 17]. H NMR: d: 7.55 [m, 4H, Ar],
306.1, 289.7, 2J(CF) = 42.5, 1/2|2J(PC) + 4J(PC)| = 12.6].
7.61 [m, 2H, Ar], 7.91 [m, 4H, Ar]. 13C{ H} NMR: d: 120.8
1
−1
−1
=
Raman (cm ): 141 m(Pd–I). IR (Nujol, cm ): 1734 m(C C), 1319,
1157, 1051 m(C–F).
1
1
3
=
[CF CF2, dvtdd, J(CF) = 266.6, 1/2| J(PC) + J(PC)| = 35.7,
2J(CF) = 31.9, 15.5], 122.7 [Ci, vt, 1/2|1J(PC) + J(PC)| = 30.9],
3
i
5
trans-[PdCl2{P Pr2(CF CF2)}2], 9. 19F NMR: d: −83.7 (trans)
129.1 [Cm, vt, 1/2|3J(PC) + J(PC)| = 5.8], 133.5 [CP, s], 135.9
=
[dd, 2J(FF) = 45 Hz, 3J(FF) = 33 Hz], −97.7 (cis) [dd, 2J(FF) =
[Co, vt, 1/2| J(PC) + J(PC)| = 7.7], 158.6 [CF CF2, dddvt,
2
4
=
45 Hz, J(FF) = 117 Hz], −182.8 (gem) [ddvt, 1/2|2J(PF) +
1J(CF) = 307.1, 290.7, 2J(CF) = 39.6, 1/2|2J(PC) + J(PC)| =
3
4
4J(PF)| = 12 Hz, J(FF) = 33 Hz, J(FF) = 117 Hz]. Raman
14.5]. Raman (cm ): 143 m(Pd–I). IR (Nujol, cm ): 1728 m(C C),
1316, 1159, 1049 m(C–F).
3
3
−1
−1
=
−1
−1
=
(cm ): 331 m(Pd–Cl). IR (Nujol, cm ): 1738 m(C C), 1304, 1157,
1030 m(C–F).
cis/trans-[PtCl2{P Pr2(CF CF2)}2], 16. 19F NMR: d: −83.7
i
=
i
2
3
4
trans-[PdBr2{P Pr2(CF CF2)}2], 10. 19F NMR: d: −84.6
(trans) [dd, J(FF) = 44 Hz, J(FF) = 32 Hz, J(PtF) = 5 Hz],
=
2
3
4
(trans) [dd, 2J(FF) = 46 Hz, 3J(FF) = 32 Hz], −97.2 (cis)
−98.2 (cis) [dd, J(FF) = 44 Hz, J(FF) = 116 Hz, J(PtF) =
2
3
4
[dd, J(FF) = 46 Hz, J(FF) = 116 Hz], −180.0 (gem) [ddvt,
1/2|2J(PF) + 4J(PF)| = 13 Hz, 3J(FF) = 32 Hz, 3J(FF) =
116 Hz]. Raman (cm−1): 191 m(Pd–Br). IR (Nujol, cm−1): 1738
45 Hz], −183.2 (gem) [ddvt, 1/2|2J(PF) + J(PF)| = 16 Hz,
3J(FF) = 32 Hz, J(FF) = 116 Hz, J(PtF) = 91 Hz]. Raman
3
3
−1
−1
=
(cm ): 300 m(Pt–Cl). IR (Nujol, cm ): 1740 m(C C), 1306, 1156,
1032 m(C–F).
=
m(C C), 1314, 1152, 1032 m(C–F).
112 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
i
trans-[PtBr2{P Pr2(CF CF2)}2], 17. 19F NMR: d: −84.7
trans-[PtI2{PPh(CF CF2)2}2], 22. 19F NMR: d: −79.7 (trans)
=
=
2
3
4
3
2
3
(trans) [dd, J(FF) = 45 Hz, J(FF) = 32 Hz, J(PtF) = 10 Hz],
[dd, J(FF) = 31, J(FF) = 29], −93.6 (cis) [dd, J(FF) = 119,
2
3
4
4
3
−98.0 (cis) [dd, J(FF) = 45 Hz, J(FF) = 116 Hz, J(PtF) =
2J(FF) = 29, J(PtF) = 39], −176.8 (gem) [ddvt, J(FF) = 119,
46 Hz], −180.5 (gem) [ddvt, 1/2|2J(PF) + J(PF)| = 15 Hz,
3J(FF) = 31, 1/2|2J(PF) + J(PF)| = 19, 3J(PtF) = 57]. 1H NMR
4
4
3J(FF) = 32 Hz, J(FF) = 116 Hz, J(PtF) = 81 Hz]. Raman
(CDCl3): d: 7.56 [m, 4H, Ar], 7.66 [m, 2H, Ar], 7.96 [m, 4H, Ar].
3
3
−1
−1
1
3
(cm ): 206 m(Pt–Br). IR (Nujol, cm ): 1738 m(C C), 1313, 1156,
1032 m(C–F).
13C{ H} NMR: d: 121.6 [Ci, vt, 1/2|1J(PC) + J(PC)| = 34.8],
=
1
1
3
=
121.9 [CF CF2, dvtdd, J(CF) = 264.6, 1/2| J(PC) + J(PC)| =
5
44.4, 2J(CF) = 43.5, 16.4], 129.1 [Cm, vt, 1/2|3J(PC) + J(PC)| =
trans-[PtI2{P Pr2(CF CF2)}2], 18. 19F NMR: d: −85.6 (trans)
i
=
4
6.8], 133.5 [CP, s], 136.4 [Co, vt, 1/2|2J(PC) + J(PC)| = 7.8],
2
3
4
[dd, J(FF) = 48 Hz, J(FF) = 31 Hz, J(PtF) = 16 Hz], −97.3
1
2
=
158.9 [CF CF2, dddvt, J(CF) = 307.1, 292.6, J(CF) = 40.6,
2
3
4
(cis) [dd, J(FF) = 48 Hz, J(FF) = 115 Hz, J(PtF) = 47 Hz],
4
1/2|2J(PC) + J(PC)| = 13.5]. Raman (cm−1): 155 m(Pt–I). IR
−176.1 (gem) [ddvt, 1/2|2J(PF) + J(PF)| = 15 Hz, J(FF) =
4
3
−1
=
(Nujol, cm ): 1728 m(C C), 1325, 1161, 1055 m(C–F).
31 Hz, J(FF) = 115 Hz, J(PtF) = 70 Hz]. Raman (cm−1): 151
3
3
−1
=
m(Pt–I). IR (Nujol, cm ): 1738 m(C C), 1304, 1152, 1028 m(C–F).
Acknowledgements
trans-[PtCl2{PCy2(CF CF2)}2], 19. 19F NMR: d: −83.9
=
2
3
4
The authors would particularly like to thank Dr Roger Perry for
the valuable service provided over many years by the UMIST
Chemistry Department Microanalytical Service. We also thank
Johnson Matthey for the loan of precious metal complexes and
acknowledge the EPSRC for providing access to the Chemical
Database Service at Daresbury.
(trans) [dd, J(FF) = 43 Hz, J(FF) = 31 Hz, J(PtF) = 15 Hz],
2
3
4
−98.3 (cis) [dd, J(FF) = 48 Hz, J(FF) = 116 Hz, J(PtF) =
43 Hz], −182.2 (gem) [ddvt, 1/2|2J(PF) + J(PF)| = 15 Hz,
4
3J(FF) = 31 Hz, J(FF) = 116 Hz, J(PtF) = 70 Hz]. Raman
3
3
−1
−1
=
(cm ): 333 m(Pt–Cl). IR (Nujol, cm ): 1736 m(C C), 1312, 1147,
1049 m(C–F).
cis/trans-[PtCl2{PPh(CF CF2)2}2], 20. 19F NMR: cis-
=
References
3
2
isomer: d: −76.5 (trans) [dd, J(FF) = 33, J(FF) = 30], −93.4
(cis) [dd, 3J(FF) = 118, 2J(FF) = 30], −178.4 (gem) [ddd, 3J(FF) =
1 See for example, J. H. Downing and M. B. Smith, in Comprehensive
Coordination Chemistry II, ed. J. A. McCleverty and T. J. Meyer,
Elsevier Ltd., Oxford, UK, 2004, ch. 1.12.
2 C. A. Tolman, Chem. Rev., 1977, 77, 313.
3 See for example, H.-Y. Liu, K. Eriks, A. Prock and W. P. Giering,
Organometallics, 1990, 9, 1758.
4 J. Chatt and R. G. Wilkins, J. Chem. Soc., 1952, 273.
5 See for example, R. A. Mansson, A. H. Welsh, N. Fey and A. G. Orpen,
J. Chem. Inf. Model., 2006, 46, 2591.
3
2
118, J(FF) = 33, J(PF) = 37], trans-isomer: d: −78.3 (trans)
3
2
3
[dd, J(FF) = 31, J(FF) = 31], −95.3 (cis) [dd, J(FF) = 117,
3
3
2J(FF) = 31], −180.9 (gem) [ddvt, J(FF) = 117, J(FF) = 31,
4
1/2|2J(PF) + J(PF)| = 21]. 1H NMR: d: 7.54 [m, 4H, Ar], 7.67
1
[m, 2H, Ar], 7.95 [m, 4H, Ar]. 13C{ H} NMR: trans-isomer d: 116.8
1
1
3
=
[CF CF2, dvtdd, J(CF) = 263.7, 1/2| J(PC) + J(PC)| = 43.8,
2J(CF) = 40.6, 15.5], 117.0 [Ci, vt, 1/2|1J(PC) + 3J(PC)| =
33.8, 2J(PtC) = 9.7], 128.1 [Cm, vt, 1/2|3J(PC) + 5J(PC)| =
6 K. D. Cooney, T. R. Cundari, N. W. Hoffman, K. A. Pittard, M. D.
Temple and Y. Zhao, J. Am. Chem. Soc., 2003, 125, 4318.
7 See for example, S. Jeulin, S. Duprat de Paule, V. Ratovelomanana-
Vidal, J. P. Genet, N. Champion and P. Dellis, Angew. Chem., Int. Ed.,
2004, 43, 320; R. A. Baber, M. L. Clark, K. M. Heslop, A. C. Marr,
A. G. Orpen, P. G. Pringle, A. Wards and D. E. Zambrano-Williams,
Dalton Trans., 2005, 1079; R. B. DeVashe, J. M. Spruell, D. A. Dixon,
G. A. Broker, S. T. Griffin, R. D. Rogers and K. H. Shaughnessy,
Organometallics, 2005, 24, 962; R. Wursche, T. Debaerdemaeker, M.
Klinga and B. Rieger, Eur J. Inorg. Chem., 2000, 2063; E. Rivard, A. D.
Sutton, J. C. Fettinger and P. P. Power, Inorg. Chim. Acta, 2007, 360,
1278.
8 D. M. Roddick and R. C. Schnabel, ACS Symp. Ser., 1994, 555, ch. 27.
9 R. D. W. Kemmitt, D. I. Nichols and R. D. Peacock, J. Chem. Soc. A,
1968, 1898; A. C. Ontko, J. F. Houlis, R. C. Schnabel, D. M. Roddick,
T. P. Fong, A. J. Lough and R. H. Morris, Organometallics, 1998, 17,
5467 and references therein; A. M. Trzeciak, H. Bartosz-Bechowski, Z.
Ciunik, K. Niesyty and J. J. Ziolkowski, Can. J. Chem., 2001, 79, 752;
W. Mohr, G. A. Stark, H. J. Jiao and J. A. Gladysz, Eur. J. Inorg. Chem.,
2001, 925; L. Villanueva, M. Arroyo, S. Bernes and H. Torrens, Chem.
Commun., 2004, 1942.
10 F. W. Bennett, H. J. Emeleus and R. N. Haszeldine, J. Chem. Soc.,
1953, 1565; M. B. Murphy-Jolly, L. C. Lewis and A. J. M. Caffyn,
Chem. Commun., 2005, 4479 and references therein.
11 J. D. Palcic, P. N. Kapoor, D. M. Roddick and R. G. Peters, Dalton
Trans., 2004, 1644; J. L. Butikofer, J. M. Hoerter, R. G. Peters and
D. M. Roddick, Organometallics, 2004, 23, 400.
12 I. T. Horva´th and J. Rabai, Science, 1994, 266, 72; I. T. Horva´th,
Acc. Chem. Res., 1998, 31, 641 and references therein;; E. G. Hope,
R. D. W. Kemmitt, D. R. Paige and A. M. Stuart, J. Fluorine Chem.,
1999, 99, 197; P. Bhattacharyya, B. Croxtall, J. Fawcett, J. Fawcett, D.
Gudmunsen, E. G. Hope, R. D. W. Kemmitt, D. R. Paige, D. R. Russell,
A. M. Stuart and D. R. W. Wood, J. Fluorine Chem., 2000, 101, 247
and references therein.
4
6.8], 132.5 [CP, s], 134.6 [Co, vt, 1/2|2J(PC) + J(PC)| = 7.8],
1
2
=
158.4 [CF CF2, dddvt, J(CF) = 308.1, 293.6, J(CF) = 39.6,
1/2|2J(PC) + 4J(PC)| = 15.5]. Raman (cm−1): trans-isomer
−1
=
305 m(Pt–Cl). IR (Nujol, cm ): 1728 m(C C), 1331, 1159, 1061
m(C–F).
cis/trans-[PtBr2{PPh(CF CF2)2}2], 21. 19F NMR: cis-isomer
=
3
2
d: −76.9 (trans) [dd, J(FF) = 33, J(FF) = 29], −93.1 (cis) [dd,
2
4
3J(FF) = 120, J(FF) = 29, J(PtF) = 44], −177.2 (gem) [ddd,
3
2
3
3J(FF) = 120, J(FF) = 33, J(PF) = 36, J(PtF) = 68], trans-
isomer d: −78.8 (trans) [dd, 3J(FF) = 32, 2J(FF) = 29], −94.5 (cis)
[dd, 3J(FF) = 117, 2J(FF) = 29, 4J(PtF) = 39], −179.3 (gem) [ddvt,
4
3J(FF) = 117, 3J(FF) = 32, 1/2|2J(PF) + J(PF)| = 20, 3J(PtF) =
57]. 1H NMR: d: 7.56 [m, 4H, Ar], 7.69 [m, 2H, Ar], 7.94 [m, 4H,
13
1
1
=
Ar]. C{ H} NMR: cis-isomer d: 117.9 [CF CF2, dddd, J(CF) =
261.8, 1J(PC) = 89.8, 2J(CF) = 44.4, 15.5], 118.3 [Ci, vt, 1J(PC) =
74.9, 2J(PtC) = 28.0], 129.4 [Cm, d, 3J(PC) = 13.0], 134.3 [CP, d,
4J(PC) = 2.9], 135.4 [Co, d, 2J(PC) = 13.5, 3J(PtC) = 25.1], 159.6
1
2
2
=
[CF CF2, dddd, J(CF) = 309.0, 293.6, J(CF) = 39.6, J(PC) =
3
26.6], trans-isomer d: 119.3 [Ci, vt, 1/2|1J(PC) + J(PC)| = 34.3],
1
1
3
=
120.4 [CF CF2, dvtdd, J(CF) = 265.6, 1/2| J(PC) + J(PC)| =
5
43.8, 2J(CF) = 39.6, 15.5], 129.3 [Cm, vt, 1/2|3J(PC) + J(PC)| =
4
6.8], 133.9 [CP, s], 136.3 [Co, vt, 1/2|2J(PC) + J(PC)| = 7.7],
1
2
=
159.6 [CF CF2, dddvt, J(CF) = 307.1, 292.6, J(CF) = 39.6,
1/2|2J(PC) + 4J(PC)| = 14.9]. Raman (cm−1): trans-isomer
−1
=
216 m(Pt–Br). IR (Nujol, cm ): 1732 m(C C), 1317, 1159, 1057
13 K. K. Banger, A. K. Brisdon and A. Gupta, Chem. Commun., 1997,
m(C–F).
139.
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 101–114 | 113
©

View Article Online
14 K. K. Banger, R. P. Banham, A. K. Brisdon, W. I. Cross, G. Damant, S.
Parsons, R. G. Pritchard and A. Sousa-Pedares, J. Chem. Soc., Dalton
Trans., 1999, 427.
15 R. N. Sterlin, R. D. Yatsenko, L. N. Pinkina and I. L. Knunyants, Izv.
Akad. Nauk SSSR, Otd. Khim. Nauk, 1960, 11, 1991.
26 C. A. Tolman, J. Am. Chem. Soc., 1970, 92, 2953.
27 S. Otto and A. Roodt, Inorg. Chim. Acta, 2004, 357, 1; A. Roodt, S.
Otto and G. Steyl, Coord. Chem. Rev., 2003, 245, 121.
28 The Cambridge Structural Database, F. H. Allen, Acta Crystallogr.,
Sect. B, 2002, 58, 380.
16 N. A. Barnes, A. K. Brisdon, M. J. Ellis, W. I. Cross and R. G. Pritchard,
J. Fluorine Chem., 2001, 112, 35.
17 N. A. Barnes, A. K. Brisdon, F. R. W. Brown, W. I. Cross, I. R. Crossley,
C. Fish, J. V. Morey, R. G. Pritchard and L. Sekhri, New J. Chem., 2004,
28, 828.
18 N. A. Barnes, A. K. Brisdon, J. G. Fay, R. G. Pritchard and J. E. Warren,
Inorg. Chim. Acta, 2005, 358, 2543.
29 B. Bertsch-Frank and W. Frank, Acta Crystallogr., Sect. C, 1996, 52,
328.
30 J. Fawcett, E. G. Hope, D. R. Russell, A. M. Stuart and D. R. W. Wood,
Polyhedron, 2001, 20, 321.
31 L. Heuer, M. Sell, R. Schmutzler and D. Schomburg, Polyhedron, 1987,
6, 1295; L. Heuer, P. G. Jones and R. Schmutzler, J. Fluorine Chem.,
1990, 46, 243.
19 R. G. Peters, J. D. Palcic and R. G. Baughman, Acta Crystallogr., Sect.
E, 2003, 59, m1198.
32 Q.-B. Bao, S. J. Geib, A. L. Rheingold and T. B. Brill, Inorg. Chem.,
1987, 26, 3453.
33 G. B. Robertson, P. A. Tucker and W. A. Wickramasinghe,
Aust. J. Chem., 1986, 39, 1495.
34 W. P. Schaefer, D. K. Lyon, J. A. Labinger and J. E. Bercaw, Acta
Crystallogr., Sect. C, 1992, 48, 1582.
35 T. Even, A. R. J. Genge, A. M. Hill, N. J. Holmes, W. Levason and M.
Webster, J. Chem. Soc., Dalton Trans., 2000, 655.
36 A. Babai, G. B. Deacon and G. Meyer, Z. Anorg. Allg. Chem., 2004,
630, 399.
20 See for example, M. S. Holt, J. H. Nelson and N. W. Alcock, Inorg.
Chem., 1986, 25, 2288; J. A. Rahn, M. S. Holt, M. O’Neil-Johnson and
J. H. Nelson, Inorg. Chem., 1988, 27, 1316; J. A. Rahn, M. S. Holt,
G. A. Gray, N. W. Alcock and J. H. Nelson, Inorg. Chem., 1989, 28,
217; X. L. R. Fontaine, D. P. Markham and B. L. Shaw, J. Organomet.
Chem., 1990, 391, 123; J. M. Kesler, J. H. Nelson, J. S. Frye, A. DeClan
and J. Fischer, Inorg. Chem., 1993, 32, 1048; N. W. Alcock, W. L.
Wilson and J. H. Nelson, Inorg. Chem., 1993, 32, 3193; L. P. Barthel-
Rosa, V. J. Catalano and J. H. Nelson, J. Chem. Soc., Chem. Commun.,
1995, 1629; L. P. Barthel-Rosa, V. J. Catalano, K. Maitra and J. H.
Nelson, Organometallics, 1996, 15, 3924; S. J. Coles, P. Faulds, M. B.
Hursthouse, D. G. Kelly, G. C. Ranger, A. J. Toner and N. M. Walker,
J. Organomet. Chem., 1999, 586, 234; M. B. Hursthouse, D. G. Kelly,
M. E. Light and A. J. Toner, Can. J. Chem., 2000, 78, 1073.
21 C. Corcoran, J. Fawcett, S. Friedrichs, J. H. Holloway, E. G. Hope,
D. R. Russell, G. C. Saunders and A. M. Stuart, J. Chem. Soc., Dalton
Trans., 2000, 161.
22 J. M. Kesler, J. H. Nelson, J. S. Frye, A. DeClan and J. Fischer, Inorg.
Chem., 1993, 32, 1048.
23 M. J. Atherton, K. S. Coleman, J. Fawcett, J. H. Holloway, E. G. Hope,
A. Karac¸ar, L. A. Peck and G. C. Saunders, J. Chem. Soc., Dalton
Trans., 1995, 4029.
24 A. H. Cowley and M. W. Taylor, J. Am. Chem. Soc., 1969, 91, 1929.
25 S. Stafford and F. G. A. Stone, Spectrochim. Acta, 1961, 17, 412.
37 J. Fawcett, E. G. Hope, R. D. W. Kemmitt, D. R. Paige, D. R. Russell
and A. M. Stuart, J. Chem. Soc., Dalton Trans., 1998, 3751.
38 B. C. Taverner, STERIC, University of the Witwatersrand, South
Africa, 1995.
39 S. Serron, S. P. Nolan and K. G. Moloy, Organometallics, 1996, 15,
4301.
40 N. A. Barnes, A. K. Brisdon, M. Nieuwenhuyzen, R. G. Pritchard and
G. C. Saunders, J. Fluorine Chem., 2007, 128, 943.
41 G. M. Sheldrick, SHELXTL, Siemens Analytical X-ray Instruments,
Madison, WI, 1995.
42 G. M. Sheldrick, SHELX-97, Universita¨t Go¨ttingen, Go¨ttingen, Ger-
many, 1998.
43 A. L. Spek, Acta Crystallogr., Sect. A, 1990, 46, C34.
44 C. F. Macrae, P. R. Edgington, P. McCabe, E. Pidcock, G. P. Shields,
R. Taylor, M. Towler and J. van de Streek, J. Appl. Crystallogr., 2006,
39, 453.
114 | Dalton Trans., 2008, 101–114
This journal is
The Royal Society of Chemistry 2008
©