Formation and cleavage of platinacycles containing a fluorinated imine. Crystal structure of [PtMe(3,4,5-C6HF3CH=NCH2C6H 5)PPh3]

Article abstract of DOI:10.1016/S0277-5387(01)00971-8

The reaction of [Pt₂Me₄(μ-SMe₂)₂] with the ligand 3,4,5-C₆H₂F₃CH=NCH₂C ₆H₅ (L) yielded the cyclometallated platinum(II) compound [PtMe(3,4,5-C₆HF₃CH=NCH₂C₆H ₅)SMe₂] (1), in which the imine acts as a [C,N]-bidentate ligand. Compounds [PtMe(3,4,5-C₆HF₃CH=NCH₂C₆H ₅)DMSO] (2) (DMSO = dimethyl sulfoxide) and [PtMe(3,4,5-C₆HF₃CH=NCH₂C₆H ₅)PPh₃] (3) were obtained from a displacement reaction of SMe₂ for DMSO or PPh₃, respectively. Oxidative addition of methyl iodide to compounds 1-3 produced, respectively, [PtMe₂I(3,4,5-C₆HF₃CH=NCH₂C ₆H₅)SMe₂] (4a/4b) as two isomers, [{PtMe₂I(3,4,5-C₆HF₃CH=NCH₂C ₆H₅)}₂] (5) and [PtMe₂I(3,4,5-C₆HF₃CH=NCH₂C ₆H₅)PPh₃] (6). Platinum(II) metallacycles can be cleaved upon reaction with an excess of PPh₃ or with the diphosphine dppe to yield, respectively, compounds [PtMe(3,4,5-C₆HF₃CH=NCH₂C₆H ₅)(PPh₃)₂] (7) and [PtMe(3,4,5-C₆HF₃CH=NCH₂C₆H ₅)dppe] (8) in which the imine acts as a monodentate [C] ligand. Analogous compounds could not be obtained for platinum(IV) since in this case neither PPh₃ nor dppe can cleave the metallacycle. The reaction of 4a/4b with dppe produced [{PtMe₂I(3,4,5-C₆HF₃CH=NCH₂C ₆H₅)}₂dppe] (11), a binuclear compound in which the diphosphine bridges two platinum(IV) moieties with the imine acting as a [C,N]-bidentate ligand. All compounds were characterised by analytical and spectroscopic techniques and compound 3 was also characterised crystallographically.

Full text of DOI:10.1016/S0277-5387(01)00971-8

Polyhedron 21 (2002) 105–113
www.elsevier.com/locate/poly
Formation and cleavage of platinacycles containing a fluorinated
imine. Crystal structure of
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)PPh3]
Margarita Crespo a,*, Merce` Font-Bard´ıa b, Xavier Solans b
a Departament de Qu´ımica Inorga`nica, Facultat de Qu´ımica, Uni6ersitat de Barcelona, Diagonal 647, E-08028 Barcelona, Spain
b Departament de Cristal.lografia, Mineralogia i Dipo`sits Minerals, Uni6ersitat de Barcelona, Mart´ı i Franque`s s/n, E-08028 Barcelona, Spain
Received 3 August 2001; accepted 5 October 2001
Abstract
The reaction of [Pt2Me4(m-SMe2)2] with the ligand 3,4,5-C6H2F3CHꢀNCH2C6H5 (L) yielded the cyclometallated platinum(II)
compound [PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)SMe2] (1), in which the imine acts as a [C,N]-bidentate ligand. Compounds
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)DMSO] (2) (DMSO=dimethyl sulfoxide) and [PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)PPh3] (3)
were obtained from a displacement reaction of SMe2 for DMSO or PPh3, respectively. Oxidative addition of methyl iodide to
compounds 1–3 produced, respectively, [PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)SMe2] (4a/4b) as two isomers, [{PtMe2I(3,4,5-
C6HF3CHꢀNCH2C6H5)}2] (5) and [PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)PPh3] (6). Platinum(II) metallacycles can be cleaved upon
reaction with an excess of PPh3 or with the diphosphine dppe to yield, respectively, compounds [PtMe(3,4,5-
C6HF3CHꢀNCH2C6H5)(PPh3)2] (7) and [PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)dppe] (8) in which the imine acts as a monodentate
[C] ligand. Analogous compounds could not be obtained for platinum(IV) since in this case neither PPh3 nor dppe can cleave the
metallacycle. The reaction of 4a/4b with dppe produced [{PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)}2dppe] (11), a binuclear com-
pound in which the diphosphine bridges two platinum(IV) moieties with the imine acting as a [C,N]-bidentate ligand. All
compounds were characterised by analytical and spectroscopic techniques and compound 3 was also characterised crystallograph-
ically. © 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Platinum; Cyclometallation; Imine; Fluorine; Phosphine; Crystal structures
fluorine [2–4] or a chlorine [5,6] atom in the position
adjacent to the M–C(aryl) bond seems to be decisive.
On the other hand, both palladium(II) [7] and platinu-
m(II) [6,8,9] metallacycles are cleaved easily with
diphosphines such as 1,2-bis(diphenylphosphino)-
ethane, which can be explained by the chelating nature
of this ligand. Nevertheless, examples in which the
formation of either compounds containing a bridging
diphosphine [10] or ionic compounds with a chelate
diphosphine [11] is favoured over cleavage of the metal-
lacycles have also been reported.
In this paper we report new cyclometallated platinum
compounds containing the imine 3,4,5-C6H2F3CHꢀ
NCH2C6H5 and their reactions with phosphines in or-
der to analyse the factors governing the cleavage of the
formed metallacycles.
1. Introduction
Cyclometallated complexes of the Group 10 elements
have generated considerable interest due to their nu-
merous applications and interesting properties. Previ-
ous results showed that the reactions with phosphines
could be taken as a criterion for the stability of metalla-
cycles [1]. Moreover, it has been shown that steric
crowding in the co-ordination sphere of the metal fa-
voured the cleavage of metallacycles upon reaction with
triphenylphosphine. In particular, the presence of a
* Corresponding author. Fax: +34-93-4907-725.
E-mail address: margarita.crespo@qi.ub.es (M. Crespo).
0277-5387/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0277-5387(01)00971-8

106
M. Crespo et al. / Polyhedron 21 (2002) 105–113
2. Results and discussion
ever, compound 2 was recovered unchanged when
treated under such conditions. The presence of the PPh3
ligand in 3 is confirmed by 31P NMR spectroscopy and
the value of the coupling constant to platinum (J(P–
Pt)=2631 Hz) is in the expected range for a phosphine
with a fluorinated aryl group in trans. In the 19F NMR
spectra, three distinct resonances appear in the aro-
matic region and the values of the coupling constants
are in the range expected for analogous compounds
[15].
Compound 3 was also characterised crystallographi-
cally. Suitable crystals were grown from acetone solu-
tion. The crystal structure is composed of discrete
molecules separated by van der Waals interactions. A
view of the molecule is shown in Fig. 1. Selected bond
lengths and angles are given in Table 1. As expected
from spectroscopic characterisation, the methyl group
is trans to the nitrogen atom, the CꢀN group is endo to
the cycle and the imine adopts an (E)-configuration, the
torsion angle C(6)–C(7)–N–C(8) being −173.99(4)°.
The platinum atom displays a tetrahedral distorted
planar co-ordination and the following displacements
The reaction of [Pt2Me4(m-SMe2)2] with ligand 3,4,5-
C6H2F3CHꢀNCH2C6H5 (L) yielded the cyclometallated
platinum(II) compound [PtMe(3,4,5-C6HF3CHꢀNCH2-
C6H5) SMe2] (1) by ortho metallation with loss of
methane, as reported for analogous systems [3,4]. Com-
pound 1 reacted with an excess of dimethylsulfoxide
(DMSO) or with PPh3 in a 1:1 molar ratio to yield
respectively compounds [PtMe(3,4,5-C6HF3CHꢀNCH2-
C6H5)DMSO] (2) and [PtMe(3,4,5-C6HF3CHꢀNCH2-
C6H5)PPh3] (3) which result from a displacement reac-
tion of SMe2 for DMSO or PPh3. The reaction of
compound 2 with PPh3 gave compound 3 which indi-
cates the lability order SMe2\DMSO\PPh3 for these
platinum(II) compounds. Compounds 1–3, shown in
Scheme 1, were characterised by elemental analysis and
NMR spectroscopies. In the 1H NMR spectra, the
methyl group bound to platinum is coupled to the
fluorine atom in position five of the aryl ring, thus
revealing a through-space interaction; additional cou-
pling to the phosphorous atom is observed for com-
pound 3. The methyl, the imine and the methylene
hydrogens are coupled to 195Pt and the values of the
coupling constants are characteristic of this kind of
cyclometallated platinum(II) compounds. For com-
pound 2, the J(H–Pt) value of the protons of DMSO
[12] and the l(195Pt) value [13] indicate that DMSO is
S-bonded to platinum; this is further confirmed by a
strong band at 1110 cm−1 in the IR spectrum. A
process involving oxidative cycloplatination and sulfur
deoxygenation has been reported in the reaction be-
tween (E)-2-methyl-1-phenylbutan-1-one oxime and
cis-[PtCl2(DMSO)2] in refluxing methanol [14]; how-
,
(A) are observed from the least-squares plane of the
co-ordination sphere: Pt, −0.0264; P, 0.1658; N,
−0.1785; C(1), 0.2074; C(15), −0.1683. The metallacy-
cle is approximately planar; the largest deviation from
the mean plane determined by the five atoms is
,
−0.0628 A for C(1). The dihedral angle between the
metallacycle and the co-ordination plane is larger
(10.24°) than those reported for [PtMe(2,3,4-
C6HF3CHꢀNCH2C6H5)PPh3] (4.6°) [3] and [PtMe-
(2,3,4-C6HF3CHꢀNCH2CH2NMe2)] (0.28°) [4]. A larger
deviation from coplanarity reduces the steric interaction
between the methyl group and the fluorine substituent
Scheme 1.

M. Crespo et al. / Polyhedron 21 (2002) 105–113
107
for the van der Waals radii to overlap. The coupling
between the methyl protons and 19F in the NMR
spectrum implies that this interaction persists in solu-
tion. Bond lengths and angles are well within the range
of values obtained for analogous compounds [3,4,16].
The ‘bite’ angle C(1)–Pt–N of 79.08(17) is characteris-
tic of cyclometallated platinum(II) complexes [17].
Oxidative addition of methyl iodide to compound 1
carried out in CDCl3 at NMR scale produced a mixture
of two isomers of platinum(IV) compound
[PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)SMe2] (4a/4b) in
nearly equal amounts together with a very small
amount (less than 5% of the reaction mixture) of com-
pound 5 (see below). The spectral parameters for com-
pounds 4 are in good agreement with those reported in
the literature for analogous compounds [18] and are
assigned to the isomers depicted in Scheme 2, which
differ only in having a SMe2 or an I trans to the axial
methyl. For both isomers only the equatorial methyl is
coupled to the fluorine at position five of the aryl ring.
Oxidative addition of methyl iodide to compound 2
gave compound 5 as a pale yellow solid which was
characterised by NMR and FAB spectroscopies. Of the
two methyl resonances—both coupled to platinum—
the one at lower field is assigned to the equatorial
methyl which is also coupled to the fluorine atom F5.
Fig. 1. Molecular structure of compound 3.
Table 1
,
Selected bond lengths (A) and bond angles (°)
Bond lengths
1
Pt–C(15)
Pt–N
P–C(28)
P–C(22)
F(2)–C(3)
N–C(7)
C(1)–C(2)
C(2)–C(3)
C(4)–C(5)
C(6)–C(7)
C(13)–C(12)
C(12)–C(11)
C(10)–C(9)
2.053(6)
2.144(4)
1.816(5)
1.833(5)
1.344(6)
1.279(6)
1.384(7)
1.379(7)
1.366(8)
1.451(7)
1.349(9)
1.359(9)
1.368(8)
Pt–C(1)
Pt–P
2.064(5)
2.2815(12)
1.824(5)
1.360(6)
1.354(6)
1.489(7)
1.409(7)
1.360(8)
1.388(7)
1.498(7)
1.373(8)
1.387(8)
1.366(8)
The absence of coordinated S– or O–DMSO in the H
and IR spectra points to an iodide bridged platinu-
m(IV) dimer, a structure that is confirmed by FAB
mass spectrometry. Moreover, since resonances due to
SMe2 are not observed, the formation of dimethyl-
sulfide from DMSO within the co-ordination sphere of
platinum as described in the literature for analogous
systems[14] can be ruled out. The low affinity of the
DMSO ligand for platinum(IV) has already been shown
in the reaction of cis-[PtMe2(DMSO)2] with methyl
iodide which yields the platinum(IV) tetramer
[{PtMe3(m3-I)}4] [19]. The l(195Pt) value obtained for 5
(−2700 ppm) is similar to that reported in the litera-
ture for the tetramer (−2769 ppm) [20]. Oxidative
addition of methyl iodide to compound 3 produced
cyclometallated platinum(IV) compound [PtMe2I(3,4,5-
C6HF3CHꢀNCH2C6H5)(PPh3)] (6) which was charac-
terised by elemental analyses and NMR spectra. Two
methyl resonances appear at l=1.38 (2J(Pt–H)=60
Hz) and l=2.20 (2J(Pt–H)=69 Hz) both coupled to
195Pt and 31P (3J(P–H)=8 Hz). The small value of the
coupling constant of the axial methyl with platinum
suggest a trans arrangement of this group and the PPh3
ligand, as reported previously for analogous com-
pounds [8]. The equatorial methyl is also coupled to the
fluorine atom at position five of the aryl ring. The
J(P–Pt) value is in the range expected for platinum(IV)
compounds, which is considerably reduced compared to
that of the platinum(II) compound. Alternatively, com-
pound 6 could be prepared upon reaction of com-
Pt–C(16)
F(1)–C(2)
F(3)–C(4)
N–C(8)
C(1)–C(6)
C(3)–C(4)
C(5)–C(6)
C(8)–C(9)
C(13)–C(14)
C(11)–C(10)
C(9)–C(14)
Bond angles
C(15)–Pt–C(1)
C(1)–Pt–N
94.8(2)
79.08(17)
167.76(13)
106.5(2)
101.7(2)
110.25(15)
119.3(4)
126.6(3)
135.0(4)
C(15)–Pt–N
C(15)–Pt–P
N–Pt–P
C(28)–P–C(22)
C(28)–P–Pt
C(22)–P–Pt
169.3(2)
90.58(18)
97.17(11)
101.6(2)
117.48(16)
117.67(17)
113.6(3)
112.3(4)
112.3(3)
120.2(5)
118.2(5)
119.1(4)
118.3(4)
C(1)–Pt–P
C(28)–P–C(16)
C(16)–P–C(22)
C(16)–P–Pt
C(7)–N–C(8)
C(8)–N–Pt
C(7)–N–Pt
C(2)–C(1)–C(6)
C(6)–C(1)–Pt
C(4)–C(3)–C(2)
C(4)–C(5)–C(6)
C(5)–C(6)–C(7)
N–C(7)–C(6)
C(2)–C(1)–Pt
C(3)–C(2)–C(1) 124.3(5)
C(3)–C(4)–C(5) 119.9(5)
C(5)–C(6)–C(1) 125.0(5)
C(1)–C(6)–C(7) 115.8(4)
N–C(8)–C(9)
116.4(4)
in a position adjacent to the Pt–C(aryl) bond. Never-
theless, the distance C(15)···F(1) of 2.929 A can be
taken as an indication of a short contact between the
methyl group and the fluorine, which are close enough
,

108
M. Crespo et al. / Polyhedron 21 (2002) 105–113
pounds 4a/4b or 5 obtained in situ in acetone with the
equivalent amount of triphenylphosphine and all
preparative methods lead to the same stereoisomer in
which the bulky triphenylphosphine is in an axial posi-
tion. The lability order DMSO\SMe2\PPh3 is de-
duced for platinum(IV) compounds.
Cleavage of the metallacycle in platinum(II) com-
pounds was achieved upon reaction of compound 1
with two equivalents of PPh3 or with one equivalent of
are much larger (412 Hz (7) and 385 Hz (8)) than those
obtained for cyclometallated compounds 1 (140 Hz), 2
(98 Hz) and 3 (87 Hz). The large value of the coupling
constant may arise from a perpendicular orientation of
the aryl group to the co-ordination plane [21]. The
methyl group consistently does not couple with the
fluorine in position five of the aryl ring.
In spite of the easy cleavage of the metallacycle
reported above for platinum(II) compounds, cy-
clometallated platinum(IV) compound 6 did not react
further with triphenylphosphine even when large ex-
cesses were used. Other attempts to obtain
triphenylphosphine platinum(IV) derivatives in which
the imine acts as a monodentate [C] ligand were also
unsuccessful. For instance, the reaction of platinum(II)
compound [PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)(PPh3)2]
(7) with methyl iodide gave a mixture of cyclometal-
lated platinum(IV) compound 6, characterised as
above, and the phosphonium salt [PPh3Me]I, for which
1H and 31P NMR data are consistent with the values
given in the literature [22]. In this process, oxidative
addition of methyl iodide took place along with co-or-
dination of the dangling imine nitrogen to platinum
and dissociation of the phosphine, which gave the
phosphonium salt. This result can be related to the
higher affinity of platinum(IV) for nitrogen than for
phosphorus donor ligands due to its harder nature.
the
bidentate
phosphine
1,2-bis(diphenylphos-
phino)ethane (dppe) to yield, respectively, compounds
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)(PPh3)2] (7) and
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)dppe]
(8)
(see
Scheme 3) which were obtained as white solids and
characterised by elemental analyses and NMR spectro-
scopies. In both cases, the methyl resonance is coupled
to two non-equivalent phosphorus atoms and the value
of the coupling constants with 195Pt are reduced (2J(Pt–
H)=65 Hz (7) or 67 Hz (8)) when compared to that of
cyclometallated compound 3 (83 Hz). Moreover, the
imine proton is not coupled to 195Pt and the 31P NMR
spectra show two sets of resonances due to two non-
equivalent phosphorus atoms, both coupled to plat-
inum. These results indicate that two phosphorus atoms
are present in the co-ordination sphere of platinum(II)
and therefore the imine is acting as a monodentate
ligand through the aryl carbon. As observed previously
3
for analogous compounds [3,4], the J(Pt–F5) values
Scheme 2.

M. Crespo et al. / Polyhedron 21 (2002) 105–113
109
Scheme 3.
two methyl resonances appear at l=1.05 (2J(Pt–H)=
59 Hz) and l=1.83 (2J(Pt–H)=69 Hz) both coupled
to 195Pt and to one phosphorus atom (J(Pt–P) ca. 7–8
Hz), and the equatorial methyl also coupled to the
fluorine atom at position five of the aryl ring. As in
compound 6, these values suggest a trans arrangement
of the axial methyl and the phosphorus atom and a
fac-PtC3 stereochemistry. The imine proton is also cou-
pled to 195Pt (3J(Pt–H)=47 Hz) indicating that the
metallacycle has not been cleaved. Two resonances
appear in the 31P NMR spectrum at l= −10.4 (J(Pt–
P)=1049 Hz) and l= −10.9 (J(Pt–P)=1048 Hz);
these values are characteristic of phosphines bound to
platinum(IV) and trans to a methyl group [9], and can
only be assigned to two different conformations of
compound 11. When larger amounts of diphosphine
were used the main products are compound 11 and free
diphosphine or its oxide. No evidence of formation of
compounds containing chelate diphosphine was ob-
On the other hand, compound [PtMe(3,4,5-
C6HF3CHꢀNCH2C6H5)dppe] (8) did not react with
methyl iodide even after 48 h when evidence of decom-
position was observed. For the purpose of comparison,
the reaction with methyl iodide was also tested for
compound [PtMe(3,4,5-C6HF3CHꢀNCH2CH2NMe2)-
(dppe)] (9) obtained from [PtMe(3,4,5-C6HF3CHꢀ
NCH2CH2NMe2)] [4] in which the terdentate imine
3,4,5-C6HF3CHꢀNCH2CH2NMe2 acts as a monoden-
tate [C] ligand. The reaction of compound 9 with
methyl iodide is shown in reaction 1 and produced the
ionic compound [PtMe(3,4,5-C6HF3CHꢀNCH2CH2-
NMe3)(dppe)]I (10) resulting from methylation of the
amine group. NMR data are similar to those obtained
for 9 except for the fact that the amine protons are
shifted towards higher fields (l=3.43 ppm) and inte-
grate nine hydrogen atoms. An analogous process in
which methyl iodide is added to the dangling NMe2
moiety but not to the platinum centre has been de-
scribed for compound [PtMe(3-C6H3ClCHꢀNCH2CH2-
NMe2)(dppe)] [6].
1
served in the H or in the 31P NMR; the formation of
such compounds requires dissociation of either nitrogen
or iodide, and it is likely that such processes are not
favoured for platinum(IV) compounds.
In view of these results, the reaction of compounds
4a/4b—obtained in situ from 1—with dppe in the ratio
2:1 was also tested. A yellow non-electrolyte solid was
obtained and was characterised as binuclear platinu-
m(IV) compound [{PtMe2I(3,4,5-C6HF3CHꢀNCH2-
C6H5)}2(dppe)] (11) by NMR and FAB Mass spectra.
Compound 11 could not be isolated in a pure form due
to decomposition processes during attempted crystalli-
In conclusion, while platinum(II) metallacycles
derived from imine 3,4,5-C6H2F3CHꢀNCH2C6H5 can
be opened up using a diphosphine or an excess of a
monodentate phosphine, platinum(IV) metallacycles are
much more resistant to cleavage. Moreover, oxidative
addition to platinum(II) compound [PtMe(3,4,5-
C6HF3CHꢀNCH2C6H5)(PPh3)2] (7) in which the imine
acts as a [C] ligand favours the co-ordination of the
1
sation in several solvents. In the H NMR spectrum

110
M. Crespo et al. / Polyhedron 21 (2002) 105–113
imine nitrogen to yield a [C,N] platinum(IV) cy-
clometallated compound. These results could be ex-
plained by the higher affinity of platinum(IV) for
nitrogen donor ligands when compared to the softer
platinum(II).
(1.74×10−4 mol) of compound [Pt2Me4(m-SMe2)2]
with 87.6 mg (3.52×10−4 mol) of the ligand 3,4,5-
C6H2F3CHꢀNCH2C6H5 in acetone (20 ml). After con-
tinuous stirring during 16 h, the solvent was removed in
a rotary evaporator and the resulting orange solid was
washed with hexane (2×10 mL) and dried under vac-
uum. Yield 140 mg (77%). 1H NMR (acetone-d6):
3. Experimental
1H, 19F, 31P–{1H} and 195Pt NMR spectra were
recorded by using Varian Gemini 200 (1H, 200MHz),
Varian 300 (19F, 282.2 MHz; 195Pt, 64.2 MHz) and
Bruker 250 (31P, 101.25 MHz) spectrometers, and refer-
enced to SiMe4 (1H), CCl3F (19F), H3PO4 (31P) and
H2PtCl6 (195Pt). l values are given in ppm and J values
in Hz. IR spectra were recorded as KBr disks on a
Nicolet 520 FT-IR spectrometer. Conductivity mea-
surements were carried out to a Crison 2000 equipment.
Microanalyses and FAB mass spectra were performed
by the Serveis Cient´ıfico-Te`cnics de la Universitat de
Barcelona.
2
l=1.13 [d, J(Pt–H)=80, J(F–H)=6, Mea]; 1.90 [s,
3J(Pt–H)=36, Mec]; 5.19 [s, 3J(Pt–H)=13, Hd];
3
{7.28–7.38 [m], aromatics}; 8.96 [s, J(Pt–H)=56, He].
19F NMR (acetone-d6): l= −122.61 [dt, J(Pt–F5)=
140, J(F5–F4)=23, J(F5–F3)=J(F5–H)=5, F5];
−146.95 [m, F3]; −159.89 [ddd, J(Pt–F4)=100,
J(F4–F5)=24, J(F4–F3)=20, J(F4–H)=7, F4]. Anal.
Found: C, 39.4; H, 3.6; N, 2.9. Calc. for C17H18F3NSPt:
C, 39.23; H, 3.49; N, 2.69%.
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)-
DMSO] (2) was obtained by adding two drops of
DMSO to 50 mg (9.6×10−5 mol) of compound 1 in
dichloromethane (20 ml). After continuous stirring dur-
ing 1 h, the solvent was removed in a rotary evaporator
and the oily residue was washed with diethylether (3×
5 ml). The obtained yellow solid was dried in vacuum.
Yield 35 mg (68%). 1H NMR (CDCl3): l=0.95 [d,
3.1. Preparation of the compounds
Compounds [Pt2Me4(m-SMe2)2] [23] and [PtMe(3,4,5-
C6HF3CHꢀNCH2CH2NMe2)] [4] were prepared as
reported.
3
The ligand 3,4,5-C6H2F3CHꢀNCH2C6H5 (L) was pre-
pared by the reaction of 0.5 g (3.1×10−3 mol) of the
corresponding aldehyde with an equimolecular amount
(0.33 g) of benzylamine in refluxing ethanol. The mix-
ture was refluxed for 2 h, and the solvent was removed
in a rotary evaporator to yield a yellow oil. Yield 0.65
2J(Pt–H)=80, J(F–H)=6, Mea]; 2.78 [s, J(Pt–H)=
20, Mec], 5.28 [s, 3J(Pt–H)=5, Hd]; {7.14 [m, 1H];
3
7.30–7.41 [m, 5H], aromatics}; 8.62 [s, J(Pt–He)=62,
He]. 19F NMR (CDCl3): l= −120.91 [dt, J(Pt–F5)=
98, J(F5–F4)=22, J(F5–F3)=J(F5–H)=7, F5]; −
142.97 [dt, J(F3–F4)=18, J(F3–F5)=J(F3–H)=7,
F3]; −156.46 [m, J(Pt–F4)=43, J(F4–F5)=22, J(F4–
F3)=18, J(F4–H)=6, F4]. 195Pt NMR (CDCl3): l=
−3982 [s]. IR (KBr): 1110 cm−1 (w(SO)). FAB(+) MS
(NBA, m/z): 521 ([M−Me]+); 443 ([M–Me–SOMe2]+).
Anal. Found: C, 37.6; H, 3.4; N, 2.6. Calc. for
C17H18F3NOPtS: C, 38.06; H, 3.38; N, 2.61%.
1
g (83%). H NMR (CDCl3): l=4.82 [s, Hd]; 7.42 [m,
aromatics]; 8.24 [s, He]. 19F NMR (CDCl3): l=
−140.09 [dd, J(Fa–Fb)=20, J(Fa–H)=8, Fa];
−163.14 [tt, J(Fa–Fb)=20, J(Fb–H)=6, Fb].
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)
SMe2] (1) was obtained by the reaction of 100 mg

M. Crespo et al. / Polyhedron 21 (2002) 105–113
111
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)-
8.52 [s, He]. 19F NMR (CDCl3): l= −109.17 [dd,
J(Pt–F5)=390, J(F5–F4)=30, J(P–F5)=16, F5];
−144.31 [m, F3]; −161.64 [m, F4]. 31P NMR (acetone-
d6): l=46.37 [s, J(Pt–PA)=1718, PA]; 47.27 [dd,
J(Pt–PB)=2274, J(PB–F5)=16, J(PB–F4)=8, PB].
\M=2.3 V−1 cm2 mol−1 (10−3 M in acetone). Anal.
Found: C, 53.9; H, 4.7; N, 3.2. Calc. for
C38H39F3N2P2Pt: C, 54.48; H, 4.69; N, 3.34%.
PPh3] (3) was obtained from the reaction of 50 mg
(9.6×10−5 mol) of compound 1 with the equimolecu-
lar amount (25 mg) of PPh3 in acetone (20 ml). After
continuous stirring during 2 h, the solvent was removed
in a rotary evaporator and the resulting yellow solid
was washed with hexane (2×5 ml), and diethylether
(2×5 ml) and dried under vacuum. Yield 55 mg (80%).
1H NMR (acetone-d6): l=0.97 [dd, 2J(Pt–H)=83,
Compound [PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)-
(SMe2)] (4a/4b) was obtained from 20 mg of compound
1 (3.84×10−5 mol) and 10 mL of methyl iodide in 0.7
ml of CDCl3 in a 5 mm NMR tube and was character-
3J(P–H)=9, J(F–H)=6, Mea]; 4.22 [s, J(Pt–H)=8,
3
Hd]; {6.79 [m, 1H]; 7.40 [m], 7.64 [m], aromatics}; 8.63
[s, 3J(Pt–He)=55, He]. 19F NMR (acetone-d6): l=
−122.62 [m, J(Pt–F5)=87, J(F5–F4)=24, J(P–F5)=
J(F5–F3)=J(F5–H)=7, F5]; −146.01 [m, F3];
−159.80 [m, F4]. 31P NMR (acetone-d6): l=29.79 [dd,
J(Pt–P)=2631, J(P–F5)=10, J(P–F4)=7]. Anal.
Found: C, 54.7; H, 3.8; N, 2.0. Calc. for
C33H27F3NPPt: C, 55.00; H, 3.78; N, 1.94%.
1
ised by NMR spectra. H NMR (CDCl3): l={0.81 [s,
2
2J(Pt–H)=68], 1.46 [s, J(Pt–H)=70], Mea}; {1.72 [d,
2J(Pt–H)=68, J(F–H)=6], 2.10 [d, 2J(Pt–H)=68,
J(F–H)=7], Meb}; 2.21 [s, 3J(Pt–H)=15, Mec]; 5.25–
3
3
5-50 [m, Hd]; {8.12 [s, J(Pt–H)=47], 8.30 [s, J(Pt–
H)=42], He}.
Compound
[{PtMe2I(3,4,5-C6HF3CHꢀNCH2C6-
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)-
H5)}2] (5) was obtained as a pale yellow solid from the
reaction of an excess of methyl iodide (0.1 ml) with 50
mg (9.3×10−5 mol) of compound 2 carried out in
acetone (20 ml). The mixture was stirred for 3 h, and
the solvent was removed under vacuum. The residue
was washed with diethylether (3×5 ml) and dried
(PPh3)2] (7) was obtained as a white solid by an
analogous procedure using 100 mg (1.9×10−4 mol) of
PPh3. Yield 80 mg (85%). H NMR (acetone-d6): l=
1
2
3
3
0.27 [dd, J(Pt–H)=65, J(PA–H)=8, J(PB–H)=7,
Mea]; {4.74 [d], 4.87 [d], J(H–H)=13, AB pattern,
Hd}; 7.13–7.24 [m, aromatics]; 9.40 [s, He]. 19F NMR
(acetone-d6): l= −113.96 [ddd, J(Pt–F5)=412,
J(F5–F4)=30, J(P–F5)=15, J(F5–F3)=3, F5];
−148.54 [m, F3]; −164.33 [ddt, J(F5–F4)=30, J(F4–
F3)=19, J(P–F4)=J(F4–H)=7, F4]. 31P NMR (ace-
1
under vacuum. Yield 35 mg (63%). H NMR (CDCl3):
2
2
l=1.27 [s, J(Pt–H)=75, Mea]; 2.94 [d, J(Pt–H)=
69, J(F–H)=8, Meb]; {5.63 [d], 5.92 [d], J(H–H)=16,
AB pattern, Hd}; {7.01 [m, 1H]; 7.37–7.57 [m, 5H],
aromatics}; 8.05 [s, 3J(Pt–Hd)=45, He]. 19F NMR
(CDCl3): l= −127.90 [dt, J(F5–F4)=21, J(F5–F3)=
J(F5–H)=8, F5]; −142.59 [m, F3]; −153.64 [td,
J(F4–F3)=J(F4–F5)=20, J(F4–H)=7, F4]. 195Pt
NMR (CDCl3): −2700 [s]. FAB(+) MS (NBA, m/z):
1200 ([M]+); 1073 ([M−I]+); 1043 ([M−I–2Me]+);
1028 ([M−I−3Me]+); 779 ([M−I−3Me−L]+).
Anal. Found: C, 31.8; H, 2.5; N, 2.3. Calc. for
C32H30F6I2N2Pt2: C, 32.01; H, 2.52; N, 2.33%.
tone-d6):
l=25.38
[d,
J(Pt–PA)=1908,
J(PA–PB)=15, PA]; 26.01 [td, J(Pt–PA)=2311, J(PB–
PA)=J(PB–F5)=15, J(PB–F4)=8, PB]. Anal. Found:
C, 61.9; H, 4.3; N, 1.4. Calc. for C51H42F3NP2Pt: C,
62.32; H, 4.31; N, 1.44%.
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2C6H5)-
(dppe)] (8) was obtained as a white solid by an
analogous procedure using 38 mg (9.5×10−5 mol) of
dppe. Yield 70 mg (85%). H NMR (acetone-d6): l=
1
Compound [PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)-
(PPh3)] (6) was obtained as a white solid by an
analogous procedure from 50 mg (6.9×10−5 mol) of
0.48 [t, 2J(Pt–H)=67, 3J(PA–H)=3J(PB–H)=6,
Mea]; 2.44 [m, Hf,g]; 4.36 [s, Hd]; {7.12–7.32 [m], 7.45–
7.55 [m], 7.70–7.79 [m], 7.89–7.98 [m], aromatics}; 8.65
[s, He]. 19F NMR (CDCl3): l= −114.20 [dd, J(Pt–
F5)=385, J(F5–F4)=27, J(P–F5)=11, F5]; −147.38
[m, F3]; −163.92 [ddt, J(F5–F4)=29, J(F4–F3)=20,
J(P–F4)=J(F4–H)=8, F4]. 31P NMR (acetone-d6):
l=46.58 [s, J(Pt–PA)=1718, PA]; 47.36 [m, J(Pt–
PB)=2287, PB]. Anal. Found: C, 57.4; H, 4.4; N, 1.6.
Calc. for C41H36F3NP2Pt: C, 57.48; H, 4.24; N, 1.63%.
1
compound 3. Yield 50 mg (83%). H NMR (CDCl3):
2
3
l=1.38 [d, J(Pt–H)=60, J(P–H)=8, Mea]; 2.20 [t,
2J(Pt–H)=69, 3J(P–H)=J(F–H)=8, Meb]; {4.58 [d],
5.52 [d], J(H–H)=17, AB pattern, Hd}; {6.86 [m, 4H];
7.31–7.58 [m], 7.64 [m], aromatics}; 7.69 [s, 3J(Pt–
Hd)=44, He]. 19F NMR (CDCl3): l= −127.35 [dt,
J(F5–F4)=21, J(F5–F3)=J(F5–H)=7, F5]; −144.57
[m, F3]; −153.62 [td, J(F4–F3)=J(F4–F5)=21, J(F4–
H)=6, F4]. 31P NMR (CDCl3): l= −11.32 [s, J(Pt–
P)=1001]. Anal. Found: C, 47.2; H, 3.5; N, 1.6. Calc.
for C34H30F3INPPt: C, 47.34; H, 3.51; N, 1.62%.
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2CH2-
NMe2)(dppe)] (9) was obtained as a white solid by an
analogous procedure from 50 mg (1.14×10−4 mol) of
the compound [PtMe(3,4,5-C6HF3CHꢀNCH2CH2-
Compound
[PtMe(3,4,5-C6HF3CHꢀNCH2CH2-
1
NMe2)] and 45 mg of dppe. Yield 80 mg (84%). H
NMe3)(dppe)]I (10) was obtained as a yellow solid from
the reaction of an excess of methyl iodide (0.1 ml) with
35 mg (4.18×10−5 mol) of compound 9 carried out in
acetone. The mixture was stirred for 3 h, and the
NMR (acetone-d6): l=0.46 [t, J(Pt–H)=68, J(PA–
H)=3J(PB–H)=7, Mea]; 2.15 [s, Meg]; {2.20–2.45 [m],
3.26 [t, J(H–H)= 7, Hd,f,h,i} 7.14–7.76 [m, aromatics];
2
3

112
M. Crespo et al. / Polyhedron 21 (2002) 105–113
solvent was removed under vacuum. Yield 35 mg
J(Pt–P)=1048]. \M=3 V−1 cm2 mol−1 (10−3 M in
acetone). FAB(+) MS (NBA, m/z): 1471 ([M−I]+);
1456 ([M−I−Me]+); 1441 ([M−I−2Me]+); 1344
([M−2I]+); 1299 ([M−2I−3Me]+); 1192 ([M−I−
2Me−L]+); 1179 ([M−I−3Me−L]+).
(85%). H NMR (acetone-d6): l=0.43 [t, J(Pt–H)=
69, 3J(PA–H)=3J(PB–H)=7, Mea]; 3.43 [s, Meg];
{3.60–3.90 [m], H d,f,h,i}; 7.13–7.84 [m, aromatics]; 8.53
[s, He]. 19F NMR (CDCl3): l= −108.75 [ddd, J(Pt–
F5)=390, J(F5–F4)=30, J(P–F5)=15, J(F5–F3)=4,
F5]; –143.75 [m, F3]; −160.30 [m, F4]. 31P NMR
(acetone-d6): l=47.28 [s, J(Pt–PA)=1711, PA]; 47.39
[dd, J(Pt–PB)=2293, J(PB–F5)=15, J(PB–F4)=8,
PB]. \M=103 V−1 cm2 mol−1 (10−3 M in acetone).
Anal. Found: C, 46.0; H, 4.5; N, 2.7. Calc. for
C39H42F3IN2P2Pt.2H2O: C, 46.12; H, 4.56; N, 2.76%.
[{PtMe2I(3,4,5-C6HF3CHꢀNCH2C6H5)}2dppe] (11)
was obtained using the following procedure: 50 mg
(9.6×10−5 mol) of compound 1 was treated with an
excess of methyl iodide (0.1 ml) in acetone (20 ml) with
continuous stirring for 30 min. The solvent was re-
moved in a rotary evaporator and the residue was
treated with 19 mg (4.7×10−5 mol) of dppe in acetone
(20 ml). The mixture was stirred for 1 h and the solvent
was removed under vacuum. The residue was washed
with hexane (3×5 ml) and the resulting white solid was
dried under vacuum. Yield 63 mg (82%). 1H NMR
1
2
3.2. X-ray structure analysis: data collection
A prismatic crystal (0.1×0.1×0.2 mm) was selected
and mounted on a MAR345 diffractometer with an
image plate detector. Unit cell parameters were deter-
mined from automatic centring of 6890 reflections (3B
qB31°) and refined by least-squares method.
Intensities were collected with graphite monochroma-
tized Mo Ka radiation. 7346 reflections were measured
in the range 2.37BqB24.95°, 4108 of which were
non-equivalent by symmetry (Rint (on I)=0.021). A
total of 3820 reflections were assumed as observed
applying the condition I\2|(I). Lorentz polarisation
and absorption corrections were made.
3.3. Structure solution and refinement
The structure was solved by direct methods, using
SHELXS computer program [24], and refined by the
full-matrix least-squares method, with the SHELXL-97
computer program [25] using 4108 reflections (very
negative intensities were not assumed). The function
2
3
(acetone-d6): l=1.05 [d, J(Pt–H)=59, J(P–H)=8,
Mea]; 1.83 [t, 2J(Pt–H)=69, J(P–H)=J(F–H)=7,
Meb]; 2.43 [m, Hf]; {4.27 [d], 5.47 [d], J(H–H)=15, AB
pattern, Hd}; 7.18–7.35 [m, aromatics]; 8.04 [s, J(Pt–
3
He)=47, He]. 19F NMR (acetone-d6): l= −128.07 [m,
F5]; −144.03 [m, F3]; −153.92 [m, F4]. 31P NMR
(acetone-d6): l= −10.4 [s, J(Pt–P)=1049]; −10.9 [s,
2
2 2
minimised was S wꢀꢀFoꢀ −ꢀFcꢀ ꢀ , where w=[|2(I)+
(0.0374P)2+3.1998P]−1 and P=(ꢀFoꢀ +2ꢀFcꢀ )/3. f, f %
and f %% were taken from the International Tables of
X-ray Crystallography [24]. 20 H were located from a
difference synthesis and refined with an overall
isotropic temperature factor and 7 H atoms were com-
puted and refined, using a riding model, with an
isotropic temperature factor equal to 1.2 times the
equivalent temperature factor of the atom to which
they are linked. Further details are given in Table 2.
2
2
Table 2
Crystallographic details
Formula
Fw
Temperature (K)
C33H27F3NPPt
720.62
293(2)
,
Wavelength, A
0.71069
triclinic
Crystal system
Space group
(
P1
Unit cell dimensions
4. Supplementary material
,
a (A)
9.0350(10)
11.2170(10)
14.2390(10)
90.63
105.299(10)
92.62
1390.1(2)
2
1.722
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
V (A )
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Centre, CCDC No. 167426. Copies of this information
may be obtained free of charge from The Director,
CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK
(fax: +44-1233-336-033; e-mail: deposit@ccdc.cam.
ac.uk or www: http://www.ccdc.cam.ac.uk).
3
,
Z
Dcalc (Mg m−3
)
Absorption coefficient (mm−1
F(000)
)
5.148
704
q Range for data collection (°)
No. of reflections collected/unique
2.37–24.95
7346/4108
[Rint=0.0219]
4108/0/432
1.076
Acknowledgements
No. of data/restraints/parameters
Goodness-of-fit on F2
R1(I\2|(I))
This work was supported by the DGICYT (Ministe-
rio de Educacio´n y Cultura, Spain, BQU2000-0652)
and from the Generalitat de Catalunya (project 1997-
SGR-00174).
0.0259
wR2 (all data)
Largest difference peak and hole (e A
0.0668
0.710, −0.642
−3
,
)

M. Crespo et al. / Polyhedron 21 (2002) 105–113
113
zovsky, O.G. Dyachenko, V.A. Polyakov, L.G. Kuz’mina, J.
Chem. Soc., Dalton Trans. (1997) 4385.
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