Synthesis of New Anionic Perhalophenylplatinate(II) Complexes

Article abstract of DOI:10.1081/SIM-120026543

Action of HCl on dichlorobis(pentafluorophenyl)platinate(II) complexes results on the cleavage of one of the Pt-C bonds and coordination of a Cl ligand. If the reaction takes place in the presence of a neutral ligand, L, it is incorporated instead of Cl to the coordination sphere of the metal. AgC ₆X₅ (X = F, Cl) has been used as an arylating agent towards platinum derivatives with Cl ligands, which has allowed the preparation of new complexes with both C₆F₅ and C₆Cl ₅ groups bonded to the same metal center. Analytical data, conductance measurements and spectroscopic methods (IR, ¹H and ¹⁹F NMR) have been used to characterize the new complexes. The structure of complex (n-Bu₄N)₂[Pt(C₆Cl ₅)(C₆F₅)₃] also has been determined by single crystal X-ray analysis.

Full text of DOI:10.1081/SIM-120026543

SYNTHESIS AND REACTIVITY IN INORGANIC AND METAL-ORGANIC CHEMISTRY
Vol. 33, No. 10, pp. 1723–1739, 2003
Synthesis of New Anionic
Perhalophenylplatinate(II) Complexes
*
Irene Ara, Juan Fornie´s, Sagrario Ramos,
and Milagros Toma´s
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales
de Arago´n, Universidad de Zaragoza-C.S.I.C., Zaragoza, Spain
ABSTRACT
Action of HCl on dichlorobis(pentafluorophenyl)platinate(II) complexes
results on the cleavage of one of the Pt–C bonds and coordination of a Cl
ligand. If the reaction takes place in the presence of a neutral ligand, L, it
is incorporated instead of Cl to the coordination sphere of the metal.
AgC6X5 (X = F, Cl) has been used as an arylating agent towards
platinum derivatives with Cl ligands, which has allowed the preparation
of new complexes with both C6F5 and C6Cl5 groups bonded to the same
metal center. Analytical data, conductance measurements and spectro-
scopic methods (IR, 1H and 19F NMR) have been used to characterize the
*
Correspondence: Juan Fornie´s, Departamento de Qu´ımica Inorga´nica, Instituto de
Ciencia de Materiales de Arago´n, Universidad de Zaragoza-C.S.I.C., 50009 Zaragoza,
Spain; E-mail: juan.fornies@unizar.es.
1723
DOI: 10.1081/SIM-120026543
0094-5714 (Print); 1532-2440 (Online)
www.dekker.com
Copyright D 2003 by Marcel Dekker, Inc.

1724
Ara et al.
new complexes. The structure of complex (n-Bu4N)2[Pt(C6Cl5)(C6F5)3]
also has been determined by single crystal X-ray analysis.
Key Words: Pentahalophenyl ligands; Anionic complexes; Platinum(II);
Pt–C bond cleavage; Arylation processes.
INTRODUCTION
Our group has been engaged for quite a long time in the synthesis of
anionic perhalophenyl platinate or palladate complexes of different
stoichiometries. The use of C6X5Li or C6X5MgBr (X = F, Cl) is the more
common way to arylate the metal centers. The number of C6X5 groups
introduced into the coordination sphere depends on the arylation agent used,
the metal center and the ancillary ligands L bonded to the metal center. A
detailled account is given in the literature.[1] The use of [MCl2L2] as
starting material allows the isolation of the neutral [MCl(C6X5)L2] or
[M(C6X5)2L2]. [MCl4]2– or MCl2 can be arylated to anionic [trans-MCl2
(C6X5)2]2– or [M(C6X5)4]2–
.
In the course of our current research on the use of these anionic
substrates as building blocks for supramolecular compounds, we have
noticed the different structural roles played by the C6F5 or C6Cl5 ligands, not
only on the structure of the resulting compound but also on the type of
complex obtained.[2] For this reason we thought it would be interesting to
prepare mixed complexes[3] such as [cis-M(C6F5)2(C6Cl5)2]2–. However,
these syntheses are not trivial since these complexes usually cannot be ob-
tained by direct procedures. For instance, the arylation of [trans-
PtCl2(C6F5)2]2– with (C6Cl5) Li does not yield [Pt(C6F5)2(C6Cl5)2]2– but a
2–
]
mixture of complexes [Pt(C6F5)x (C6Cl5)4-x
difficult to separate.[4]
(x = 0, 1, 2) which are very
In this paper we report a new synthetic approach to prepare mixed
C6F5, C6Cl5 derivatives consisting in the use of AgC6X5 (X = F, Cl)[5] to
introduce C6X5 groups into platinum complexes containing Cl ligands by
removal of the halide ligands as AgCl and incorporation of the C6X5 group
to the coordination sphere of the metal center. This procedure has allowed
us the controlled preparation of derivatives containing both C6F5 and C6Cl5
groups bonded to the same metal center. The anionic substrates available
were very scarce, particularly pentafluorophenyl derivatives. For this reason
we have also prepared several anionic complexes containing C6F5 and Cl
groups in order to have available the adequate platinum substrates to be
used as starting materials in the reactions with AgC6X5.

Perhalophenylplatinate(II) Complexes
RESULTS AND DISCUSSION
1725
Synthesis of New Anionic Platinum
Substrates with C6F5 Groups
The action of HCl is known to produce the cleavage of Pt–C6X5
bonds. As far as the C6F5 derivatives are concerned, the reaction of
(n-Bu4N)2 [Pt(C6F5)4] with HCl yields (n-Bu4N)2[PtCl(C6F5)3] or (n-Bu4N)2
[Pt(m-Cl) (C6F5)2]2 depending onthe molar ratio used (1:1 or 1:2, respective-
ly).[6] Following this procedure we have used HCl as an abstractor of C6F5
groups and, as a result, the unusual mononuclear complex (n-
Bu4N)2[PtCl3(C6F5)] (1) has been prepared by addition of the equimolecular
amount of HCl to a solution of (n-Bu4N)2[trans-PtCl2(C6F5)2] in dichlor-
omethane (Eq. 1).
ðn-Bu4NÞ2½trans-PtCl2ðC6F5Þ2Š þ HCl
! ðn-Bu4NÞ2½PtCl3ðC6F5ފ þ HC6F5
ð1Þ
This reaction needs a prolonged work-up in order to isolate the product (see
experimental details). This result contrasts with the reaction of (n-
Bu4N)2[trans-PtCl2(C6Cl5)2], which reacts with HCl (1:1 molar ratio) resulting
in the cleavage of one Pt–C6Cl5 bond and not the mononuclear (n-
Bu4N)2[PtCl3(C6Cl5)] but the binuclear (n-Bu4N)2[Pt(m-Cl)Cl(C6Cl5)]2 is the
final product.[7]
The binuclear complex (n-Bu4N)2[Pt(m-Cl)Cl(C6F5)]2 (2) was obtained
by reacting (n-Bu4N)2[PtCl3(C6F5)] with AgClO4 in 1:1 molar ratio (Eq. 2).
The process consists of the elimination of a Cl ligand as AgCl, thus
allowing the dimerization to occur.
2 ðn-Bu4NÞ2½PtCl3ðC6F5ފ þ 2AgClO4
! ðn-Bu4NÞ2½Ptðm-ClÞClðC6F5ފ2 þ 2AgCl
ð2Þ
Again, the behaviour of the pentafluorophenyl and pentachlorophenyl
derivatives is different, since (n-Bu4N)2[Pt(m-Cl)Cl(C6Cl5)]2 was obtained
by reaction of (n-Bu4N)2[Pt(m-Cl)(C6Cl5)2]2 with HCl,[7] while (n-Bu4N)2-
[Pt(m-Cl)(C6F5)2]2 does not react with HCl.
Three different methods have been succesfully used to obtain com-
plexes of the stoichiometry (n-Bu4N)[trans-PtCl2(C6F5)L].
(a) Reaction of (n-Bu4N)[trans-PtCl2(C6F5)2] with HCl in the pre-
sence of ligand L.

1726
Ara et al.
When (n-Bu4N)2[trans-PtCl2(C6F5)2] is reacted with HCl, a Pt–C6F5
bond is cleaved and in the presence of a neutral ligand L the monoanionic
derivative (n-Bu4N)[trans-PtCl2(C6F5)L] is obtained, as shown in Eq. 3. This
behaviour had been observed before for the pentachlorophenyl derivatives.
ðn-Bu4NÞ2½trans-PtCl2ðC6F5Þ2Š þ L þ HCl
! ðn-Bu4NÞ½trans-PtCl2ðC6F5ÞLŠ þ NBu4Cl þ HC6F5
L = PPh3 (3), p-toluidine (4), AsPh3 (5)
ð3Þ
(b) Reaction of (n-Bu4N)2[trans-Pt(m-Cl)Cl(C6F5)]2 with L (1:2).
Addition of L to a solution of (n-Bu4N)2[trans-Pt(m-Cl)Cl(C6F5)]2 in
2:1 molar ratio yields the complex (n-Bu4N)[trans-PtCl2(C6F5)L] by
breaking the halide bridges (Eq. 4).
ðn-Bu4NÞ2½trans-Ptðm-ClÞClðC6F5ފ2 þ 2L
! 2ðn-Bu4NÞ½trans-PtCl2ðC6F5ÞLŠ
L = PPh3 (3)
ð4Þ
(c) Reaction of (n-Bu4N)2[PtCl3(C6F5)] with AgClO4 (1:1) in the
presence of ligand L.
When reacting equimolecular quantities of (n-Bu4N)2[PtCl3(C6F5)] and
AgClO4 in the presence of ligand L, AgCl precipitates immediately, and L
is coordinated to the metallic center giving (n-Bu4N)[trans-PtCl2(C6F5)L]
(Eq. 5).
ðn-Bu4NÞ2½PtCl3ðC6F5ފ þ AgClO4 þ L
! ðn-Bu4NÞ½trans-PtCl2ðC6F5ÞLŠ þ AgCl
þ n-Bu4NClO4
L = p-toluidine (4)
ð5Þ
Synthesis of New Mixed Anionic Platinum
Pentahalophenyl Derivatives
The reaction of (n-Bu4N)2[trans-PtCl2(C6Cl5)2] with AgC6F5 in dichlor-
omethane affords (n-Bu4N)2[trans-PtCl(C6Cl5)2(C6F5)] (6) or (n-Bu4N)2

Perhalophenylplatinate(II) Complexes
1727
[trans-Pt(Cl6C5)2(C6F5)2] (7) depending on the molar ratio of reagents. When
using a 1:1 molar ratio, only one of the Pt–Cl bonds is labilized, and only one
of the Cl groups is replaced by C6F5 (Eq. 6).
ðn-Bu4NÞ2½trans-PtCl2ðC6Cl5Þ2Š þ AgC6F5
! ðn-Bu4NÞ2½trans-PtClðC6Cl5Þ2ðC6F5ފ þ AgCl
ð6Þ
The insolubility of AgCl drives the reaction to completion rapidly and in good
yield. It is important to carefully control the quantities of reactants, since an
excess of AgC6F5 produces the precipitation of the second chloride ligand,
thus giving mixtures. When the molar ratio is 1:2 the reaction gives the
disubstituted complex (n-Bu4N)2[trans-Pt(C6Cl5)2(C6F5)2] (Eq. 7).
ðn-Bu4NÞ2½trans-PtCl2ðC6Cl5Þ2Š þ 2 AgC6F5
! ðn-Bu4NÞ2½trans-PtðC6Cl5Þ2ðC6F5Þ2Š þ 2 AgCl
ð7Þ
The action of the silver species is selective. First of all, one Cl ligand is
removed and replaced by C6F5. When this step is completed, the second Cl
ligand is eliminated to give the final complex (n-Bu4N)2[trans-Pt(C6Cl5)2-
(C6F5)2]. This behavior is different from the observed when using AgC6Cl5.
Our attempts to synthesize (n-Bu4N)2[PtCl(C6Cl5)3] by reacting (n-
Bu4N)2[trans-PtCl2(C6Cl5)2] with AgC6Cl5 (1:1 molar ratio) failed, since
both Cl ligands are removed at the same time thus giving a 1:1 mixture of
the starting material (n-Bu4N)2[trans-PtCl2(C6Cl5)2] and (n-Bu4N)2[Pt-
(C6Cl5)4].
Addition of equimolecular quantities of AgC6Cl5 to a solution of (n-
Bu4N)2[trans-PtCl2(C6F5)2] in dichloromethane yields the complex of (n-
Bu4N)2[trans-PtCl(C6Cl5)(C6F5)2] (8), after separating by filtration the
AgCl formed. The higher insolubility of AgCl as compared to AgC6Cl5
helps the reaction to go to completion (Eq. 8).
ðn-Bu4NÞ2½trans-PtCl2ðC6F5Þ2Š þ AgC6Cl5
! ðn-Bu4NÞ2½trans-PtClðC6Cl5ÞðC6F5Þ2Š þ AgCl
ð8Þ
When the reaction is carried out in 1:2 molar ratio or even by using a
higher proportion of AgC6Cl5, the final product is still the same, i.e. the
substitution of the second Cl ligand does not occur. Since the disubstituted
complex has been obtained as shown in Eq. 7, it seems that there are
kinetic, but not thermodinamic or steric reasons which preclude the reaction
to proceed any further.

1728
Ara et al.

Perhalophenylplatinate(II) Complexes
1729

1730
Ara et al.
Complex (n-Bu4N)2[Pt(C6Cl5)(C6F5)3] (9) has been obtained by the
reaction of (n-Bu4N)2[PtCl(C6F5)3] with the equimolecular amount of
AgC6Cl5 (Eq. 9).
ðn-Bu4NÞ2½PtClðC6F5Þ3Š þ AgC6Cl5
! ðn-Bu4NÞ2½PtðC6Cl5ÞðC6F5Þ3Š þ AgCl
ð9Þ
When the reaction of (n-Bu4N)2[PtCl3(C6F5)] and AgC6Cl5 was carried
out in 1:1 molar ratio, the isolated product is (n-Bu4N)2[trans-PtCl2-
(C6Cl5)(C6F5)] (10), by substitution of the Cl ligand in the trans position to
the C6F5 ligand by a C6Cl5 group (Eq. 10).
ðn-Bu4NÞ2½PtCl3ðC6F5ފ þ AgC6Cl5
! ðn-Bu4NÞ2½trans-PtCl2ðC6Cl5ÞðC6F5ފ þ AgCl
ð10Þ
In this complex the Cl ligands are also in trans positions. By adding an
excess of AgC6Cl5 another Cl ligand undergoes substitution, yielding (n-
Bu4N)2[trans-PtCl(C6Cl5)2(C6F5)] (11). However the last Cl ligand could
not be substituted, even by using large amounts of AgC6Cl5 and, in any
case, (11) was the final product (Eq. 11).
ðn-Bu4NÞ2½PtCl3ðC6F5ފ þ AgC6Cl5 ðexcessÞ
! ðn-Bu4NÞ2½trans-PtClðC6Cl5Þ2ðC6F5ފ þ AgCl
ð11Þ
Spectroscopic Data
Table 1 collects relevant IR absorptions of the new complexes due to C6F5,
C6Cl5 and Cl ligands. The most interesting absorptions of the pentafluor-
ophenyl ligands appear in the range 750–800 cm–1 (X-sensitive mode)[8] and at
about 950 and 1100 cm–1. Pentachlorophenyl ligands show absorptions near
1200 cm–1 and in the range 600–700 cm–1 corresponding to internal vibrations
of the C6Cl5 group, along with vibrations at ca. 800 cm–1 due to the X-
sensitive mode and at ca. 600 cm–1 due to n(Pt–C). The configuration of
the complexes can be established from their IR spectra, since the absorp-
tions assignable to the X-sensitive mode of either C6F5 or C6Cl5 groups,
along with those due to n(Pt–C6Cl5) allow to distinguish between the cis
and trans isomers. The X-sensitive modes of the C6Cl5 groups sometimes
appear as unresolved signals. In the case of complexes (2)–(5) and (10), the
cis or trans configuration is based on the n(Pt–Cl) absorptions.

Perhalophenylplatinate(II) Complexes
1731

1732
Ara et al.
Figure 1. Structure of the anion [Pt(C6Cl5)(C6F5)3]2À
.
19F NMR spectra were recorded for the complexes (6)–(11). They
show separate sets of signals corresponding to the F atoms in ortho, meta or
para positions and indicate that the two halves of the rings are equivalent.
All 19F NMR data are collected in Table 2.
Crystal Structure of (n-Bu4N)2[Pt(C6Cl5)(C6F5)3] (9)
As expected and as is shown in Fig. 1, the anion [Pt(C6Cl5)(C6F5)3]2–
shows a square-planar disposition of the ligands arround the platinum
center. The Pt–C distances are the same within experimental error
˚
[2.051(6) to 2.068(6) A]. The disorder found in the crystal, consisting of
having the sites of the C6Cl5 and one of the C6F5 rings occupied both by
C6Cl5 and C6F5 at 50% ocupancy each, does not allow any discussion about
differences in the Pt–C distances. Angles between adjacent groups range
from 89.0(2) to 91.3(2)ꢀ, while angles between groups in trans position are
176.9(2) and 177.3(2)ꢀ. The Pt atom does not deviate significantly from the
plane formed by the carbon atoms attached to it. Finally, the perhalophenyl
rings are oriented forming angles ranging from 61.8 to 71.4ꢀ with the
platinum plane. Table 3 collects the most important bond distances and
angles of (9).

Perhalophenylplatinate(II) Complexes
1733
˚
Table 3. Bond lengths (A) and angles
(deg) for (NBu4)2[Pt(C6Cl5)(C6F5)3]
(9).
Pt–C(1)
Pt–C(7)
2.051(6)
2.052(6)
2.056(6)
2.068(6)
89.4(2)
Pt–C(19)
Pt–C(13)
C(1)–Pt–C(7)
C(1)–Pt–C(19)
C(7)–Pt–C(19)
C(1)–Pt–C(13)
C(7)–Pt–C(13)
C(19)–Pt–C(13)
90.4(2)
177.3(2)
176.9(2)
89.0(2)
91.3(2)
EXPERIMENTAL SECTION
The C, H and N analyses were carried out on a Perkin–Elmer 240
microanalyzer. The IR spectra were recorded (4000–200 cm–1) on a
Perkin–Elmer 883 spectrophotometer as Nujol mulls supported on poly-
ethylene sheets. NMR spectra were recorded on a Varian XL 300 spec-
trometer. Conductivities were measured in approximately 5 Â 10–4
M
acetone solutions with a Philips PW 9501/01 conductimeter. Literature
methods were used for the preparation of the following starting materials:
(n-Bu4N)2[trans-PtCl2(C6Cl5)2],[9] (n-Bu4N)2[trans-PtCl2(C6F5)2],[10] (n-Bu4
N)2[trans-Pt(m-Cl)(C6Cl5)2]2,[9] (n-Bu4N)2[trans-Pt(m-Cl)(C6F5)2]2,[6]
AgC6F5,[5] AgC6Cl5.[5] All reactions were carried out at room temperature
and, when using AgClO4 or AgC6X5, also with exclusion of light.
Caution. Perchlorate salts are potentially explosive and should be used
in small quantities and with great caution.
Synthesis of (n-Bu4N)2[PtCl3(C6F5)] (1)
To a solution of 0.50 g (0.461 mmol) of (nBu4N)2[trans-PtCl2(C6F5)2]
in 20 mL of dichloromethane, 0.99 mL of a solution 0.464 N of HCl in
methanol (0.461 mmol) was added. The colour of the solution immediately
turned to deep yellow and after 1 h of stirring at room temperature the
mixture was evaporated to dryness. The resulting sticky residue was treated
with several portions of n-hexane for at least 48 h until a pale yellow solid
could be separated. Yield, 0.37g (84%). Anal. Calcd. for C38H72Cl3F5N2Pt

1734
Ara et al.
(FW 953.4): C, 47.90; H, 7.55; N, 2.94. Found: C, 47.58; H, 7.96; N,
2.91%. Molar conductivity: 131 S cm2 mol–1
.
Synthesis of (n-Bu4N)2[trans-Pt(M-Cl)Cl(C6F5)]2 (2)
A quantity of (n-Bu4N)2[PtCl3(C6F5)] (0.200 g, 0.21 mmol) was
dissolved in 20 mL of dichloromethane along with 0.0434 g (0.21 mmol) of
AgClO4. After 2 h stirring at room temperature, the white solid formed
(AgCl) was removed and the resulting solution, after being evaporated to
about 5 mL, was layered with 40 mL of n-hexane. By slow diffusion at
À 18ꢀC yellow crystals were obtained. Yield, 0.09 g (62 %). Anal. Calcd.
for C44H72Cl4F10N2Pt2 (FW 1351.03): C, 39.13; H, 5.33; N, 2.07. Found: C,
38.98; H, 5.35; N, 2.26 %. Molar conductivity: 147 S cm2 mol–1
.
Synthesis of (n-Bu4N)[trans-PtCl2(C6F5)L]
L = PPh3 (3), p-Toluidine (4), AsPh3 (5)
Three methods can be used to prepare complexes (n-Bu4N)[trans-
PtCl2(C6F5)L].
a) L = PPh3, p-toluidine, AsPh3. To a solution of (n-Bu4N)2[trans-
PtCl2(C6F5)2] (0.200 g, 0.184 mmol) in 15 mL of dichloromethane
was added ligand L in the molar ratio 1:1 (0.048 g, 0.184 mmol for
PPh3; 0.199 g, 0.184 mmol for p-toluidine; 0.056 g, 0.184 mmol
for AsPh3) and 0.397 mL of HCl 0.464 N in methanol. After 1 h of
stirring at room temperature, the solution was evaporated to
dryness and the residue treated with 5 mL of isopropyl alcohol, to
give yellow solids.
L = PPh3. Yield, 0.14 (81%). Anal. Calcd. for C40H51Cl2F5NPPt (FW
937.7): C, 51.24; H, 5.44; N, 1.49. Found: C, 51.14; H, 5.27; N, 1.40 %.
Molar conductivity: 99 S cm2 mol–1. L = p-toluidine. Yield, 0.10 (67 %).
Anal. Calcd. for C29H45Cl2F5N2Pt (FW 782.6): C, 44.50; H, 5.75; N, 3.58.
Found: C, 44.95; H, 6.27; N, 3.70 %. Molar conductivity: 92 S cm2 mol–1
.
L = AsPh3. Yield, 0.13 (72 %). Calcd. for C40H51AsCl2F5NPt (FW 981.7):
C, 48.95; H, 5.19; N, 1.43. Found: C, 48.34; H, 4.86; N, 1.25%. Molar
conductivity: 89 S cm2 mol–1
.
b) L = PPh3. 0.039 g (0.148 mmol) of PPh3 was added to a solution
of (n-Bu4N)2[trans-Pt(m-Cl)Cl(C6F5)]2] (0.100 g, 0.074 mmol) in
15 mL of dichloromethane. The solution was evaporated after 1 h of
stirring at room temperature and the oily residue was treated with

Perhalophenylplatinate(II) Complexes
1735
5 mL of isopropyl alcohol to give (3) as a yellow solid. Yield,
0.10 g (72 %).
c) L = p-toluidine. 0.132 g (0.138 mmol) of (n-Bu4N)2[PtCl3(C6F5)]
was dissolved in 15 mL of dichloromethane. To this solution,
0.0148 g (0.138 mmol) of p-toluidine and 0.0287 g (0.138 mmol)
of AgClO4 were added. After 1 h of stirring at room temperature
the white solid (AgCl) was filtered off and the solution evaporated
to dryness. To the resulting residue isopropyl alcohol was added
under stirring to give (4). Yield, 0.08 g (78 %).
Synthesis of (n-Bu4N)2[trans-PtCl(C6Cl5)2(C6F5)] (6)
To a dichloromethane solution (15 mL) of (n-Bu4N)2[trans-PtCl2-
(C6Cl5)2] (0.300 g, 0.24 mmol) AgC6F5 (0.066 g, 0.24 mmol) was added.
After 5 h of stirring at room temperature the solid formed (AgCl) was
filtered through Celite. The solution was evaporated to dryness and a few
mL of isopropyl alcohol was added to the residue to render a white solid
that was filtered, washed with isopropyl alcohol and n-hexane and air dried.
Yield, 0.28 (85%). Anal. Calcd. for C50H72Cl11F5N2Pt (FW 1381.2): C,
43.49; H, 5.21; N, 2.03. Found: C, 43.56; H, 5.60; N, 2.07%. Molar
conductivity: 171 S cm2 mol–1
.
Synthesis of (n-Bu4N)2[trans-Pt(C6Cl5)2(C6F5)2] (7)
A quantity of (n-Bu4N)2[trans-PtCl2(C6Cl5)2] (0.300 g, 0.24 mmol) was
dissolved in 15 mL of dichloromethane with 0.132 g (0.48 mmol) of
AgC6F5. Following the same procedure as above a white solid of (7) was
obtained. Yield, 0.22 (60%). Anal. Calcd. for C56H72Cl10F10N2Pt (FW
1512.8): C, 44.48; H, 4.76; N, 1.85. Found: C, 44.78; H, 4.97; N, 1.73%.
Molar conductivity: 186 S cm2 mol–1
.
Synthesis of (n-Bu4N)2[trans-PtCl(C6Cl5)(C6F5)2] (8)
A quantity of (n-Bu4N)2[trans-PtCl2(C6F5)2] (0.375 g, 0.345 mmol) in
15 mL of acetone was reacted with 0.120 g (0.345 mmol) of AgC6Cl5.
After 4 h of stirring at room temperature, the solid formed was removed
and the resulting solution evaporated to dryness. A few mL of isopropyl
alcohol were added to the residue to obtain a white solid. Yield, 0.38 g
(85%). Anal. Calcd. for C50H72Cl6F10N2Pt (FW 1298.9); C, 46.23; H, 5.54;
N, 2.16. Found: C, 46.62; H, 5.78; N, 2.30%. Molar conductivity: 178 S
cm2 mol–1
.

1736
Ara et al.
Synthesis of (n-Bu4N)2[Pt(C6Cl5)(C6F5)3] (9)
To a solution of 0.150 g (0.123 mmol) of (n-Bu4N)2[PtCl(C6F5)3] in 15
mL of dichloromethane, 0.044 g (0.123 mmol) of AgC6Cl5 was added.
After stirring for 3 h at room temperature the white solid formed (AgCl)
was filtered and the resulting solution was evaporated to dryness. The oily
residue was treated with a small quantity of isopropyl alcohol to yield a
white solid, which was filtered, washed with isopropyl alcohol and n-
hexane and air-dried. Yield, 0.14 g (82%). Anal. Calcd. for C56H72Cl5F15-
N2Pt (FW 1430.5): C, 47.02; H, 5.03; N, 1.96. Found: C, 47.17; H, 5.10; N,
1.96%. Molar conductivity: 181 S cm2 mol–1
.
Synthesis of (n-Bu4N)2[trans-PtCl2(C6Cl5)(C6F5)] (10)
A quantity of (n-Bu4N)2[PtCl3(C6F5)] (0.200 g, 0.21 mmol) and 0.075 g
(0.21 mmol) of AgC6Cl5 were mixed together in 15 mL of dichloromethane.
The suspension was stirred for 2 h at room temperature and the solid formed
was filtered. The resulting solution was evaporated to dryness and by adding
isopropyl alcohol to the residue a pale yellow solid was obtained, which was
filtered, washed with isopropyl alcohol and n-hexane and air-dried. Yield,
0.18 g (74%). Anal. Calcd. for C44H72Cl7F5N2Pt (FW 1167.3): C, 45.27;
H, 6.17; N, 2.40. Found: C, 45.19; H, 6.34; N, 2.37%. Molar conductivity:
142 S cm2 mol–1
.
Synthesis of (n-Bu4N)2[cis-PtCl(C6Cl5)2(C6F5)] (11)
To a solution of 0.300 g (0.314 mmol) of (n-Bu4N)2[PtCl3(C6F5)] in
15 mL of dichloromethane, 0.337 g (0.944 mmol) of AgC6Cl5 was added.
After stirring the mixture for 2 h at room temperature, the solid was filtered
and the solution was evaporated to dryness to give a residue, which was treated
with a few mL of isopropyl alcohol to render a white solid. This solid was
recrystallized by dissolving it in a small quantity of dichloromethane,
followed by filtration, evaporation of the solution to about 1 mL and addition
of isopropyl alcohol. Yield, 0.15 g 3 (4%). Anal. Calcd. for C50H72Cl11F5N2Pt
(FW 1381.2): C, 43.48; H, 5.21; N, 2.03. Found: C, 43.60; H, 5.05; N, 1.83%.
Molar conductivity: 182 S cm2 mol–1
.
Crystal Structure of (n-Bu4N)2[Pt(C6Cl5)(C6F5)3] (9)
Crystal data and other details of the structure analysis are presented in
Table 4. Crystals of complex (9) were grown by slow diffusion at À 18ꢀC
of n-hexane into a dichloromethane solution of the compound. A single

Perhalophenylplatinate(II) Complexes
1737
Table 4. Crystal data and structure refinement for complex (NBu4)2-[Pt(C6Cl5)-
(C6F5)3] (9).
Empirical formula
Formula weight
Temperature
C56H72Cl5F15N2Pt
1430.50
100(2) K
˚
0.71073 A
monoclinic, P2(1)/n
Wavelength
Crystal system,
space group
Unit cell dimensions
˚
a = 11.2663(9) A
b = 21.8122(14) A
a = 90°
˚
b = 92.631(2)°
g = 90°
˚
c = 24.2028(18) A
3
˚
Volume
5941.4(8) A
Z, Calculated density
Absorption coefficient
F(000)
4, 1.599 Mg/m3
2.672 mm–1
2880
Crystal size
0.24 Â 0.19 Â 0.15 mm
1.26 to 23.30 deg.
Theta range for
data collection
Limiting indices
À 12 ꢀ h ꢀ 12,
À 24 ꢀ k ꢀ 23,
À 26 ꢀ 1 ꢀ 26
Reflections collected/unique
Max. and min. transmission
Refinement method
36874/8547 [R(int) = 0.0402]
0.6900 and 0.5664
Full-matrix least-squares
on F2
Data/restraints/parameters
Goodness-of-fit on F2
8547/13/802
0.947
Final R indices [I > 2s(I)]
R indices (all data)
Largest diff. peak and hole
R1 = 0.0407, wR2 = 0.0960
R1 = 0.0573, wR2 = 0.1004
–3
˚
1.129 and À 0.907 e.A
2
2 2
2 2 1/2
R1 = S (jFoj À jFcj)/SjFoj; wR2 = [S w (Fo À Fc ) /Sw(Fc ) ]
.
2
2 2
Goodness-of-fit = [S w (Fo À Fc ) /(nobs À nparam)]1/2
.
2
w = [s2(Fo) + (g1P)2 + g2P]–1; P = [max (Fo ; 0) + 2Fc ]/3.
2
crystal was mounted on a quartz fiber in a random orientation and held in
place with fluorinated oil. Data collection was performed at 100 K
temperature on a Bruker Smart Apex CCD diffractometer using graphite
˚
monocromated Mo-Ka radiation (l = 0.71073 A) with a nominal crystal
to detector distance of 6.0 cm. A sphere of data was colleted based on
three o-scans runs (starting o = À 28ꢀ) at values f = 0, 120 and 240 with
the detector at 2q = 28ꢀ. At each of these runs, 606 frames were collected at
0.3ꢀ intervals and 10 s per frame. The diffaction frames were integrated

1738
Ara et al.
using the SAINT package[11] and corrected for absorption with SADABS.[12]
Lorentz and polarisation corrections were applied. The structure was solved
by the Patterson method. The atoms were located in succeding Fourier
syntheses. Two of the C6F5 rings were refined as expected, but we could not
clearly identify the C6F5 or C6Cl5 remaining rings, since the thermal param-
eters of the halogen atoms presented some distorsions with respect to those
expected and the C-halogen distances were intermediate between those of
C–Cl and C–F. This feature led us to consider the presence of static disorder
consisting of having the halogen positions of both rings with F or Cl at 0.5
occupancy each. This proved to be the case since the refinement parameters
were notably improved. All non-hydrogen atoms of the complex were
assigned anisotropic displacement parameters. H atoms were added at the
calculated positions with equivalent isotropic displacement parameters set
equal to 1.2 or 1.5 times those of the corresponding parent atoms. Final
–3
˚
difference electron density maps showed a single peak above 1 eA (max.
1.13, largest diff. hole À 0.91), that have no chemical meaning. The struc-
ture was refined using the SHELXL-97 program.[13]
SUPPLEMENTARY MATERIAL
Crystallographic data (excluding structure factors) for the structural
analysis have been deposited with the Cambridge Crystallographic Data
Center, CCDC number 198702 for compound 9. Copies of this information
may be obtained from The Director, CCDC, 12 Union Road, Cambridge,
CB2 1EZ, UK (fax: + + -44-1223-336-033; e-mail: deposit@ccdc.cam.ac.uk
or www: http://www.ccdc. cam.ac.uk), and are available upon request
ACKNOWLEDGMENTS
We thank the Ministerio de Ciencia y Tecnolog´ıa (Spain) for financial
support (project BQU2002-03997-CO2-02).
REFERENCES
1. Uso´n, R.; Fornie´s, J. Organopalladium and platinum compounds with
pentahalophenyl ligands. Adv. Organomet. Chem. 1988, 28, 219.
2. Fornie´s, J.; Mart´ın, A. Metal Clusters in Chemistry; Wiley-VCH, 1999;
417.
3. Uso´n, R.; Fornie´s, J.; Toma´s, M.; Ara, I.; Casas, J.M.; Mart´ın, A.

Perhalophenylplatinate(II) Complexes
1739
Neutral and anionic binuclear perhalogenophenyl platinum ! silver
complexes with Pt Ag bonds unsupported by covalent bridges. Mole-
cular structures of [(tht)(C6Cl5)(C6F5)2PtAg(PPh3)], (NBu4)
[(C6F5)4PtAg(tht)] and (NBu4)[cis-(C6Cl5)2(C6F5)2PtAg(tht)] (tht = tet-
rahydrothiophene). J. Chem. Soc., Dalton Trans. 1991, 2253.
4. Fornie´s, J.; Thomas, M. Unpublished results.
5. Uso´n, R.; Laguna, A.; Abad, J.A. Pentahalophenylargentate(I) com-
plexes. J. Organomet. Chem. 1983, 246, 341.
6. Uso´n, R.; Fornie´s, J.; Toma´s, M.; Fandos, R. Tris(pentafluorophenyl)-
platinate(II) complexes. J. Organomet. Chem. 1984, 263, 253.
7. Uso´n, R.; Fornie´s, J.; Toma´s, M.; Ara, I.; Menjo´n, B. Action of HCl upon
the Pt–C bonds in (NBu4)2[PtC6Cl5)4] and (NBu4)2[trans-PtCl2
(C6Cl5)2]: synthesis of tris(pentachlorophenyl), (NBu4) [PtC6Cl5)3L],
and dichloromonopentachlorophenyl-platinate(II), (NBu4)[trans-
PtCl2(C6Cl5)L], complexes. J. Organomet. Chem. 1987, 336, 129.
8. Maslowsky, E., Jr. Vibrational Spectra of Organometallic Compounds;
Wiley: New York, 1977; 437.
9. Uso´n, R.; Fornie´s, J.; Mart´ınez, F.; Toma´s, M.; Reoyo, I. Synthesis and
reactivity of anionic mono- and binuclear pentachlorophenyl complexes
of palladium(II) and platinum(II). Organometallics 1983, 2, 1386.
10. Uso´n, R.; Fornie´s, J.; Mart´ınez, F.; Toma´s, M. Mono- and binuclear
anionic pentafluorophenyl complexes of palladium(II) and platinum(II).
J. Chem. Soc., Dalton Trans. 1980, 888.
11. SAINT+ v 6.02; Bruker Analytical X-Ray Systems, 1999.
12. SADABS: Empirical Absorption Correction Program; Bruker Analyt-
ical X-Ray Systems, 1999.
13. Sheldrick, G.M. SHELXL-97: Program for Crystal Structure Refine-
ment; University of Go¨ttingen, 1997.
Received December 27, 2002
Accepted June 26, 2003
Referee I: R. G. Peters
Referee II: K. Moedritzer

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