Factors affecting the lability of the σ(M-X) bond in cycloplatinated and cyclopalladated complexes containing [C(sp2, ferrocene),N,X]- or [C(sp2, phenyl),N,X]- (X = S, N) terdentate ligands

Article abstract of DOI:10.1016/j.jorganchem.2004.07.007

The reactions of the cyclometallated complexes [M{[(η⁵- C₅H₃)-CH = N (C₆H₄-2-SMe)]Fe (η⁵-C₅H₅)}Cl] [with M = Pt (5a) or Pd (5b)] with PPh₃ under different experimental conditions are reported. These studies have allowed the isolation of [M{[(η⁵-C₅H₃)- CH = N-C₆ H₄-2-SMe)]Fe(η⁵-C₅H₅)} (PPh₃)]X [M = Pt and X^- = Cl^- (6a) or BF₄ (7a) or M = Pd and X^- = Cl^- (6b) or BF₄ (7b)] and the neutral comlex [Pd{[(η⁵-C₅H₃)-CH = N-(C₆ H₄-2-SMe)]Fe(η⁵-C₅H₅)}Cl (PPh₃)] (8b). In 6-7a.b the ferrocenyl Shiff base behaves as a [C(sp², ferrocene),N,S] group while in 8b it acts as a [C(sp², ferrocene),N] ligand. The X-ray crystal structure of 7b confirms the mode of binding of the ferrocenyl ligand. The comparison of the results obtained and those reported for [M{(C₆H₄)-CH = N-(CH₂-CH₂- 2-SEt)}Cl] and [M{(C₆H₄)-CH = N-(C₆ H₄-2-SMe)}Cl] {with a [C(sp², phenyl),N,S]^- terdentate ligand} or [M{[(η⁵- C₅H₃)-CH = N-(CH₂)₃- NMe₂]Fe(η⁵-C₅H₅)}Cl] {in which the ligand acts as a [C(sp², ferrocene),N,N′]^- group} have allowed the elucidation of the relative importance of the factors affecting the lability of the M-X (X = S or N′) and M-Cl bonds in cyclometallated compounds with [C,N,S]^- and [C(sp², ferrocene),N,X]^- ligands.

Full text of DOI:10.1016/j.jorganchem.2004.07.007

Journal of Organometallic Chemistry 689 (2004) 3184–3196
www.elsevier.com/locate/jorganchem
Factors affecting the lability of the r(M–X) bond in
cycloplatinated and cyclopalladated complexes containing
[C(sp2, ferrocene),N,X]ꢀ or [C(sp2, phenyl),N,X]ꢀ(X = S, N)
terdentate ligands
a
a,
a
b
Sonia Perez , Concepcion Lopez *, Amparo Caubet , Xavier Solans ,
´
´
´
Merce Font-Bardia
b
`
a
´ ` ´
Departament de Quımica Inorganica, Facultat de Quimica, Universitat de Barcelona. Martı i Franques 1-11, 08028-Barcelona, Spain
`
´ ` ´ `
Departament de Cristal lografia, Mineralogıa i Diposits Minerals, Facultat de Geologıa, Universitat de Barcelona, Martı i Franques s/n,
b
´
08028-Barcelona, Spain
Received 11 June 2004; accepted 1 July 2004
Available online 6 August 2004
Abstract
The reactions of the cyclometallated complexes [M{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}Cl] [with M = Pt (5a) or
Pd (5b)] with PPh3 under different experimental conditions are reported.These studies have allowed the isolation of [M{[(g5-
C5H3)–CH‚N–C6H4–2-SMe]Fe(g5-C5H5)}(PPh3)]X [M = Pt and Xꢀ = Clꢀ (6a) or BFꢀ4 (7a) or M = Pd and Xꢀ = Clꢀ (6b) or
BFꢀ4 (7b)] and the neutral complex [Pd{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}Cl(PPh3)] (8b). In 6–7a,b the ferrocenyl
Schiff base behaves as a [C(sp2, ferrocene),N,S]ꢀ group while in 8b it acts as a [C(sp2, ferrocene),N]ꢀ ligand. The X-ray crystal struc-
ture of 7b confirms the mode of binding of the ferrocenyl ligand.The comparison of the results obtained and those reported for
[M{(C6H4)–CH‚N–(CH2–CH2–2-SEt)}Cl] and [M{(C6H4)–CH‚N–(C6H4–2-SMe)}Cl] {with a [C(sp2, phenyl),N,S]ꢀ terdentate
ligand} or [M{[(g5-C5H3)–CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}Cl] {in which the ligand acts as a [C(sp2, ferrocene),N,N0]ꢀ group}
have allowed the elucidation of the relative importance of the factors affecting the lability of the M–X (X = S or N0) and M–Cl
bonds in cyclometallated compounds with [C,N,S]ꢀ and [C(sp2, ferrocene),N,X]ꢀ ligands.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Cyclometallation; Ferrocene; Platinacycles; Palladacycle
1. Introduction
[13–18] is also well-known. Among all the examples re-
ported so far, those containing [C,N,X]ꢀ (X = N0, O
or S) terdentate groups with three donor atoms of differ-
ent hardness [19], are particularly interesting because the
ligand may adopt different binding modes and haptici-
ties {i.e. (C,N,X)ꢀ, (C,N)ꢀ, (C)ꢀ} and the study of the
factors that affect the ease with which these changes oc-
cur is relevant from the point of view of their potential
utility in homogeneous catalysis.
Cyclometallated complexes containing platinum(II)
or palladium(II) ligands [1] have generated considerable
interest since long ago mainly due to their applications
in homogeneous catalysis or for the design of new mate-
rials with outstanding properties [1–18]. Their utility as
precursors in organic and organometallic synthesis
*
Most of the articles reported so far involve the study
of the lability of the r(M–X) bonds of cyclometallated
Corresponding author. Tel.: +34934021274; fax: +34934907725.
´
E-mail address: conchi.lopez@qi.ub.es (C. Lopez).
0022-328X/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.07.007

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S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3185
complexes [M(C,N,X)Cl] (M = Pt or Pd and X = N0 or
O) containing a r[M–C(sp2, aryl)] bond or to a lesser ex-
tent a r[M–C(sp3)] bond [20–22], but related studies on
metallacycles in which palladium(II) or platinum(II) are
bound to a C(sp2, ferrocene) atom are less common
[23,24]. To the best of our knowledge, only the reactivity
of PPh3 in CH2Cl2 at ca. 20 ꢁC for 1 h, followed by con-
centration to dryness, gave a deep purple solid, which
was identified according to its elemental analyses and
(FAB+) mass spectrum as [Pt{[(g5-C5H3)–CH‚N–
(C6H4–2-SMe)]Fe(g5-C5H5)}(PPh3)]Cl (6a) [Scheme 1,
step (a)]. Its infrared spectrum showed the typical bands
due to the coordinated PPh3 ligand [29,30] and a sharp
and intense band at ca. 1533 cmꢀ1 assigned to the
stretching of the imine group.
of
compounds:
[M{[(g5-C5H3)–CH‚N–(CH2)n–
NMe2]Fe(g5-C5H4)}Cl] {with n = 3, M = Pt (1a) or Pd
(1b) or n = 2, M = Pd (2b)} (Fig. 1(a)) [23,24] with
PPh3 has been reported. Besides that, parallel studies
involving platina- or palladacycles with a [C,N,S]ꢀter-
dentate group are scarce [25–27] and the examples
reported so far are practically restricted to: [M{(C6H5)–
CH‚N–(CH2–CH2–2-SEt)}Cl] {M = Pt (3a), Pd (3b)}
and [M{(C6H5)–CH‚N–(C6H4–2-SMe)}Cl] {M = Pt
(4a), Pd (4b)} (Fig. 1(b) and (c)) which contain a
[C(sp2, phenyl),N,S]ꢀ ligand [25,26]. Compounds 3–
4a,b undergo the cleavage of the M–S bond in the pres-
ence of PPh3. In the view of this and in order to clarify
the influence of the type of metallated carbon in a trans-
arrangement to the M–S bond on the lability of this link,
we were prompted to study the reactions of [M{[(g5-
C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}Cl] {M =
Pt (5a), Pd (5b)} [28] (Fig. 1(d)) with PPh3.
The 195Pt{1H} NMR spectrum of 6a (in CDCl3 at 300
K) showed a doublet at d = ꢀ4449 ppm (1JP–Pt = 3785
Hz) which is consistent with the values reported for re-
lated platinacycles with a [C,N,S]ꢀ terdentate group
[25–27,31] and its 31P{1H} NMR spectrum suggested a
cis-arrangement between the metallated carbon and
the phosphine ligand, in good agreement with the trans-
phobia effect [32].
1
In the H NMR spectrum of 6a at 300 K the signals
due to the protons of the SMe and (g5-C5H5) groups
were broad (Fig. 2(a)). This finding could be indicative
of a dynamic process in solution (possibly involving
the –SMe moiety). In order to confirm this hypothesis,
1H and 31P{1H} NMR studies were carried out in the
1
range 230–300 K. At 230 K, the H NMR spectrum,
showed two sets of superimpossed signals of relative in-
tensities 2.1:1.0 (Fig. 2(b)) and the positions of the two
signals observed in the 31P{1H} NMR spectrum [Fig.
3] were consistent with the values expected for platinacy-
cles with a PPh3 ligand in a trans-arrangement to the
imine nitrogen [20,25a,26]. The coalescence of the two
signals observed in the 31P{1H} NMR spectra was
achieved at 270 K (Fig. 3). These findings suggested
the presence of two different platinum(II) complexes
(in a molar ratio = 2.1) in CDCl3 solution.
It has been reported that some platinacycles with ter-
dentate [C(sp2, phenyl), N,N0]ꢀ ligands, such as
[Pt{(C6H4)–CH‚N–(CH2)2–NMe2]}(PPh3)]Cl, under-
go a fast exchange process in solution which involves
the cleavage of the terminal Pt–NMe2 bond and the for-
mation of a Pt–Cl bond [Scheme 2(a)] [20]. In order to
elucidate if the two species present in CDCl3 solutions
of 6a could also be related by a change in the mode of
binding of the ferrocenyl ligand {from [C(sp2, ferro-
cene),N,S]ꢀ (in 6a) to [C(sp2, ferrocene),N)]ꢀ (in 6a0)}
[Scheme 2(b)], we prepared [Pt{[(g5-C5H3)–CH‚N–
(C6H4–2-SMe)]Fe(g5-C5H5)}(PPh3)][BF4] (7a) and stud-
ied its solution behaviour in CDCl3.
2. Results and discussion
Treatment of [Pt{[(g5-C5H3)–CH‚N–(C6H4–2-
SMe)]Fe(g5-C5H5)}Cl] (5a) with the equimolar amount
(a)
(b)
H
H
C
N
n
C
N
M
Cl
M
NMe2
SEt
Cl
Fe
M=Pt (3a) or Pd (3b)
n=2, M = Pt (1a) or Pd (1b)
n=1, M = Pd (2b)
(c)
(d)
H
C
N
H
C
Complex 7a was synthesized either from 5a in the
presence of Tl[BF4] followed by the removal of TlCl
and the subsequent addition of PPh3, or from 6a using
Tl[BF4] to remove the chloro ligand bound to the plati-
num(II) [Scheme 1, steps (b) and (c)]. Proton and
31P{1H} NMR spectra of a CDCl3 solution of 7a in
the range 230–300 K were identical to those obtained
for 6a. Thus, indicating that the Clꢀ (in 6a) or the
[BF4]ꢀ (in 7a) anions were not involved in the dinamic
N
M
Cl
M
SMe
Cl
SMe
Fe
M=Pt (4a) or Pd (4b)
M=Pt (5a) or Pd (5b)
Fig. 1.

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3186
5'
5'
5'
6'
1'
6'
6'
4'
4'
4'
1'
H
H
C
1'
H
C
N
N
5
C
N
1
1
5
5
1
3'
3'
2'
2'
3'
2'
Pt SMe
Pt SMe
Pt SMe
4
2
2
4
4
Cl
(c)
2
[BF4]
(a)
i)
3
3
Cl
3
PPh3
PPh3
Fe
Fe
iii)
Fe
(5a)
(7a)
(6a)
(b)
ii), iii)
Scheme 1. (i) PPh3 in CH2Cl2 at room temperature. (ii) Tl[BF4] in acetone, followed by removal of the TlCl formed (iii) addition of the stoichiometric
amount of PPh3.
Fig. 2. 1H NMR spectra (500 MHz) of [Pt{[(g5-C5H3)–CH‚N–(C6H4-2SMe)]Fe(g5-C5H5)}(PPh3)]Cl (6a) in CDCl3 at T = 300 K (a) and 230 K (b).
process. The 31P{1H} NMR spectrum of 6a and 7a at
low temperatures suggested that the environment of
the platinum(II) should be very similar in the two spe-
cies. Besides that, {1H–1H} NOESY and ROESY spec-
tra of 7a at 230 K revealed that the two complexes
interchanged in solution and differred in the relative
arrangement of: (a) the Me group of the –SMe moiety
and one of the phenyl rings of the PPh3 and (b) the
C5H5 ring and another C6H5 group of the coordinated
phosphine.

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3187
that in 5a the Pt–S bond is less prone to cleave than in
3a or 4a or than the Pt–Namine bond in 1a.
The use of more severe experimental conditions
(PPh3: Pt molar ratios varying from 1 to 3; in acetone
or benzene, at room temperature or under reflux and
with reaction periods up to 24 h) did not produce the
cleavage of the Pt–S bond in 5a or 6a. In order to com-
pare the reactivity of the M–Cl and M–S bonds in 5a
and 5b, a parallel study was preformed with the palladi-
um(II) complex. When 5b was treated with the equimo-
lar amount of PPh3 in CH2Cl2 at ca. 20 C for 1 h,
followed by the work up, a purple residue was isolated.
1
Its H NMR spectrum in CDCl3 revealed the presence
of 5b and [Pd{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]-
Fe(g5-C5H5)}(PPh3)]Cl (6b) [Scheme 4, step (a)] in a
molar ratio = 1.0:0.3. Its 31P{1H} NMR spectrum
showed the signal of the free PPh3 {at d = ꢀ6.0 ppm}
and an additional singlet at 34.9 ppm, adscribed to com-
plex 6b (see below).
These findings are in contrast with those described for
3b and 4b for which the addition of PPh3 (in a Pd:PPh3
molar ratio = 1) produced the cleavage of the Pd–S
bond [24b,25c]. Thus indicating a smaller lability of
the Pd–S bond in 5b when compared with those of 4b
and 3b. This trend, which is similar to that described
above for the platinum(II) derivatives, can be adscribed
to the different trans-influence of the metallated carbon
atom: a C(sp2, ferrocene) atom (in 5b) or a C(sp2, phe-
nyl) atom in 3b and 4b. Besides that, the comparisson
of the results obtained reveal that 5b is less reactive than
5a in front of PPh3.
When larger excesses of PPh3 were used (molar ratio
PPh3:5b = 1.5) the relative proportion 5b:6b decreased
and 6b could be isolated in a higher yield. Complex 6b
was characterised by elemental analyses, mass spectra,
infrared and NMR spectroscopy (see Section 4). The
most outstanding features observed in the 1H NMR
spectrum of 6b are: (a) the presence of a doublet due
to phosphorous coupling at d = 9.47 ppm [4JP–H = 8.5
Hz], which is assigned to the imine proton and (b) the
resonances of the H3 and SMe protons appeared high-
field shifted when compared with those of 5b or the free
ligand due to the paramagnetic anisotropy of the phenyl
rings of the PPh3 ligand. The 31P{1H} NMR spectrum
of 6b [d = 34.9 ppm] was consistent with a cis-arrange-
ment of the PPh3 ligand and the metallated carbon of
the ferrocenyl moiety, in good agreement with the trans-
phobia effect [32]. 1H and 31P{1H} NMR spectrum of 6b
(in CDCl3) did not vary substantially in the range: 230–
300 K.
Fig. 3. 31P{1H} NMR spectra (250 MHz) of [Pt{[(g5-C5H3)–CH‚N–
(C6H4-2SMe)]Fe(g5-C5H5)}(PPh3)]Cl in CDCl3 at 300, 270, 265 and
230 K.
The results obtained in the reaction of 5a with PPh3
are in sharp contrast with those reported for [Pt{[(g5-
C5H3)–CH‚N–(CH2–CH2–CH2–NMe2)]Fe(g5-C5H5)}-
Cl] (1a), [Pt{(C6H4)–CH‚N–(CH2–CH2–2-SEt)}Cl]
(3a) and [Pt{(C6H4)–CH‚N–(C6H4–2-SMe)}Cl] (4a)
for which the addition of the equimolar amount of
PPh3 in CH2Cl2 at room temperature produced the
cleavage of the Pt–Namine (in 1a) or Pt–S (in 3a and
4a) bonds [Scheme 3(a)–(c)] [25b,26]. Thus, suggesting
For comparison purposes we also prepared and char-
acterised compound: [Pd{[(g5-C5H3)–CH‚N–(C6H4–2-
SMe)]Fe(g5-C5H5)}(PPh3)][BF4] (7b) (Scheme 4, step (b)
and Section 4). Its molecular structure consists of
equimolar amounts of [Pd{[(g5-C5H3)–CH‚N–(C6H4–
2-SMe)]Fe(g5-C5H5)}(PPh3)]+, [BF4]ꢀ anions and

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3188
NMe2
H
C
H
C
N
N
i)
Cl
Cl
Pt
NMe2
Pt
at 228 K
PPh3
PPh3
(a)
H
C
H
C
N
N
SMe
i)
Pt SMe
PPh3
Pt
Ph3P
Cl
Cl
Fe
Fe
(6a')
(b)
(6a)
Scheme 2. (i) CDCl3.
the C(6) atom of the 1,2-disubstituted pentagonal ring,
thus confirming that the ligand acts as a [C(sp2, ferro-
cene),N,S]ꢀ terdentate group. The fourth coordination
site is occupied by the phosphorous atom of the PPh3
group and a slightly distorted square-planar environ-
ment is the result.
(a)
H
C
H
C
N
N
SEt
M
Cl
SEt
M
Cl
i)
PPh3
M = Pt (3a), Pd (3b)
˚
˚
M = Pt , Pd
The Pd–C(6) [2.001(3) A], Pd–N [2.070(2) A] and Pd–
˚
S [2.3750(2) A] bond lengths are larger than the values
reported for [Pd{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]-
Fe(g -C5H5)}Cl] (5b) [Pd–C(6), 1.978(5) A; Pd–N,
(b)
5
˚
H
C
H
˚
˚
2.020(3) A and Pd–S, 2.3653(11) A][28]. The cation
contains a [5,5,5,6] tetracyclic system formed by the
1,2-disubstituted pentagonal ring of the ferrocenyl unit,
a five-membered metallacycle, the chelate ring, formed
by the binding of the two heteroatoms to the palladium,
and the phenyl ring. The metallacycle, which contains
the ˜C‚N– functional group (endocyclic), is twisted
on the Pd–C(6) bond and the five-membered chelate ring
is twisted on the Pd–S bond. Bond lengths and angles
of the ‘‘(g5-C5H5)Fe(g5-C5H3)’’ moiety are consistent
with those reported for most ferrocene derivatives [33].
The two pentagonal rings are planar (tilt angle = 2.7ꢁ)
and they deviate by ca. 2.1ꢁ from the ideal eclipsed
conformation.
C
N
N
SMe
i)
M
Cl
SMe
M
Cl
PPh3
M = Pt (4a), Pd (4b)
M = Pt, Pd
(c)
H
C
H
NMe2
N
C N
Cl
M
M
NMe2
i)
Cl
PPh3
Fe
Fe
The separation between the C(18)–H(18A) bond of
one cation and the phenyl ring formed by the set of at-
˚
oms [C(25)–C(30)] of a neigbouring unit is 2.660 A,
M = Pt (1a), Pd (1b)
Scheme 3. (i) PPh3 in CH2Cl2 at room temperature.
which suggests a C–Hꢁ ꢁ ꢁp interaction.
More interesting were the results obtained when 5b
was treated with PPh3 (in a PPh3:5b molar ratio = 1.5)
for 1 h in benzene or acetone under reflux. In this case,
the 31P{1H} NMR spectrum of the crude showed three
singlets at d = ꢀ6.0, 34.8 and 38.1 ppm. The two signals
at higher fields are due to the free PPh3 and to 6a,
CH2Cl2. The ORTEP diagram of the cation together
with the atom numbering scheme is depicted in Fig. 4.
In the cation, the palladium(II) is bound to the two
heteroatoms of the ferrocenyl ligand {N and S} and to

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3189
5'
6'
4'
1'
H
C N
5
1
3'
2'
Pd SMe
2
4
3
Cl
Fe
(d)
(a)
i)
(5b)
v), iv)
(c)
iii)-iv)
5'
4'
5'
6'
6'
3'
1'
4'
3'
H
1'
2'
H
C N
1
5
C N
SMe
5
1
1
2
2'
SMe
Pd
4
Pd Cl
PPh3
4
Cl
2
3
3
PPh3
Fe
Fe
(8b)
(6b)
(b)
ii)
5'
6'
1'
3'
H
C N
1
5
Pd SMe2'
2
4
[BF4]
3
PPh3
Fe
(7b)
Scheme 4. (i) PPh3 in CH2Cl2 at room temperature. (ii) Tl[BF4] in acetone. (iii) PPh3 (molar ratio PPh3:Pd = 1.5) in benzene under reflux for 1 h. (iv)
SiO2 column chromatography (v) PPh3 (molar ratio PPh3:Pd = 1.5) in benzene under reflux for 24 h.
respectively. The chemical shift of the remaining signal
[d = 38.2 ppm] was very similar to those reported
for palladacycles: [Pd{[(g5-C5H3)–CH‚N–R1]Fe(g5-
C5H5)}Cl(PPh3)] with (R1 = phenyl, benzyl or naphthyl
groups) in which the ferrocenyl Schiff base behaves as a
[C(sp2, ferrocene),N]ꢀ group [34]. Thus, suggesting the
presence of a new cyclopalladated derivative, here in af-
arose form 5b by cleavage of the Pd–SMe bond and
the incorporation of a PPh3 ligand in the coordination
sphere of the palladium(II). The differences observed
in the 31P NMR chemical shifts of 6b and 8b were con-
sistent with those found for other palladacycles contain-
ing [C(sp2, phenyl),N,X]ꢀ and [C(sp2, phenyl),N]ꢀ
ligands [20,22,34].
1
ter referred to as 8b [Scheme 4, step (c)]. The H NMR
The results presented here are in sharp contrast with
those reported for [Pd{[(g5-C5H3)–CH‚N–(CH2)3–
NMe2]Fe(g5-C5H5)}Cl] which in the presence of PPh3
spectrum at 300 K revealed that the two palladium(II)
compounds coexisted in a 8b:6b molar ratio = 0.13. This
ratio increased for longer reaction periods and when re-
action was carried out in refluxing benzene for 24 h, 8b
was isolated in a fairly good yield [Scheme 4, step (d)].
This product, which was identified as [Pd{[(g5-C5H3)–
CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}Cl(PPh3)]Cl (8b),
gave
[Pd{[(g5-C5H3)–CH‚N–(CH2)3–NMe2]Fe(g5-
C5H5)}Cl(PPh3)] [Scheme 3(c)] in which the ligand acts
as a [C(sp2, ferrocene),N]ꢀ bidentate group. In this case
the formation of the ionic palladacycle [Pd{[(g5-C5H3)–
CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}(PPh3)]+
could

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S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3190
Fig. 5. Molecular structure and atom numbering scheme of the
cationic array of: [Pd{[(g5-C5H3)–CH‚N–(CH2–CH2–CH2)-NMe2]-
Fe(g5-C5H5)}(PPh3)][BF4] Æ CHCl3 (9b). Hydrogen atoms are not
˚
shown for clarity. [Selected bond lengths (A) and angles (ꢁ): Pd–
C(6), 1.946(11); Pd–N(1), 2.125(4); Pd–N(2), 2.195(8); Pd–P, 2.2841(9);
C(6)–C(10), 1.482(8); C(10)–C(11), 1.456(12); C(11)–N(1), 1.290(11);
N(1)–C(12), 1.395(10); C(12)–C(13), 1.488(13); C(13)–C(14), 1.459(8);
C(14)–N(2), 1.505(6); C(6)–Pd–N(1), 82.7(3); N(1)–Pd–N(2), 89.2(3);
N(2)–Pd–P, 103.07(10); C(6)–Pd–P, 85.69(13), C(11)–N(1)–C(12),
116.1(6)].
Fig. 4. Molecular structure and atom numbering scheme of the
cationic array of: [Pd{[(g5-C5H3)–CH‚N–(C6H4-2SMe)]Fe(g5-
C5H5)}(PPh3)][BF4]CH2Cl2 (7b). Hydrogen atoms are not shown for
˚
clarity. [Selected bond lengths (A) and angles (ꢁ): Pd–C(6), 2.001(3);
Pd–N, 2.070(2); Pd–P, 2.2506(7); Pd–S, 2.3750(8); C(6)–C(10),
1.451(4); C(10)–C(11), 1.419(4); C(10)-N, 1.313(4); N-C(12), 1.406(3);
C(6)–Pd–N, 81.75(10); C(6)–Pd–P, 93.62(8); N-Pd–S, 82.48(7); P–Pd–
S, 101.85(3); C(6)–C(10)–C(11), 117.1(2); C(9)–C(10)–C(11),
132.5(3);C(10)–C(11)–N, 116.3(2); Pd–S–C(17), 95.58(10); Pd–S–
C(18), 112.62(17) and C(17)-S–C(18), 120.86(18)].
maining atoms. The six-membered ring formed by the
coordination of the two nitrogen atoms {N(1) and
N(2)} to the palladium has a half-chair conformation.
The pentagonal rings of the ferrocenyl fragment are
planar, nearly parallel (tilt angle = 4.0ꢁ) and they deviate
by ca. ꢀ6.9ꢁ from the ideal eclipsed conformation.
The comparison of structural data for compounds 7b
and 9b reveal that the sum of the bond angles around the
palladium involving the phosphorous atom: C(6)–Pd–P
and P–Pd–N(2) (in 9b) or P–Pd–S (in 7b) [195.5ꢁ] is greater
than in 9b [188.8ꢁ]. These findings together with the
shorter the Pd–N(2) bond (in 9b) when compared with
the Pd–S bond distance (in 7b) indicate that the environ-
ment of the PPh3 in 9b is more constrained than in 7b. In
fact, when 9b is treated with the equimolar amount of
LiCl in a CH2Cl2:MeOH (10:1 mixture) at ca. 20 ꢁC,
the Pd–N(amine) bond cleaves, producing [Pd{[(g5-
C5H3)–CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}Cl(PPh3)]
(Scheme 5); while for 7b more severe experimental
conditions were needed to cleave the Pd–S bond. These
only be achieved in the presence of Tl[BF4]. These find-
ings suggested that the Pd–Cl and Pd-X (X = S or N0)
bonds are more labile in [Pd{[(g5-C5H3)–CH‚N–
(CH2)3–NMe2]Fe(g5-C5H5)}Cl] than in 5b.
In a first attempt to explain the different stability of
the ionic cyclopalladated complexes holding a [C(sp2,
ferrocene),N,X]ꢀ terdentate ligands 7b and [Pd{[(g5-
C5H3)–CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}(PPh3)]
[BF4] Æ CHCl3 (9b) [23b], we decided to crystallise 9b and
to solve its crystal structure. The structure consists
of equimolar amounts of heterodimetallic cations:
[Pd{[(g5-C5H3)–CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}
(PPh3)]+, [BF4]ꢀ anions and CHCl3. The molecular
structure of the cationic array is shown in Fig. 5.
The palladium(II) atom is bound to the N(1) and
N(2) atoms of the ligand, the C(6) atom of the ferroce-
nyl group and the phosphorous atom of the PPh3 ligand
in a slightly distorted square-planar environment. The
Pd–N(2) and Pd–C(6) bond lengths do not differ signif-
icantly from those reported for [Pd{[(g5-C5H3)–
CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}Cl] (1b) [Pd–N(2),
H
H
C
C
N
N
NMe2
Pd NMe2
Pd
Cl
i)
[BF4]
˚
˚
2.205(3) A and Pd–C(6), 1.964(3) A] (the differences
do not clearly exceed 3r), but the Pd–N(1) bond in 9b
is larger than in 1b.
PPh3
Fe
Fe
PPh3
(9b)
The metallacycle has an envelope-like conformation
˚
in which the C(6) atom deviates by ca. 0.198 A [towards
the Fe(II) ion] from the main plane defined by the re-
Scheme 5. (i) LiCl in a CH2Cl2:MeOH (10:1) mixture at room
temperature for 5 min.

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3191
findings agree with the different hardness [19] of the two
heteroatoms Namine (in 9b) and S (in 7b).
ously [23a,28,35]. The solvents (except benzene) were
dried and distilled before use [36]. Some of the prepara-
tions described below require the use of HIGHLY HAZ-
ARDOUS materials such Tl[BF4] or benzene, which
should be handled with CAUTION.
3. Conclusions
Elemental analyses (C, H, N and S) were carried out
`
The results presented in this work have allowed us to
elucidate the relative importance of the metallated car-
bon atom and/or the nature of the terminal X donor at-
om of the [C,N,X]ꢀ terdentate ligands in pallada- and
platinacyles of general formulae [M(C,N,X)Cl] upon
the reactivity of the M–X bond and the M–Cl bond.
In particular, these studies reveal that: (a) the Pt–Cl
bond (in 5a) is more labile than in 5b and (b) com-
pounds 5a, 5b are less proclive to undergo a ring open-
ing process than 3–4a,b, which contain a [C(sp2, phenyl),
N,S]ꢀ ligand [25,26].
On the other hand, the variations detected in the M–L
bond length within a family of related compound has been
frequently used to rationalise the different reactivity of the
complexes towards a given ligand. Commonly, larger
r(M–L) bond distances are related to the greater lability
of the bond. The differences observed in the M–C, M–N
and M–Cl bond distances in 4a and 5a (or in 4b and 5b)
(Table 1) do not clearly exceed 3r; but in 4a and 4b the
M–S bond lengths are clearly larger than in 5a and 5b.
This finding could be indicative of a weaker M–S bond
in the metallated complexes with a [C(sp2, phenyl),N,S]ꢀ
terdentate ligand, which is consistent with the results ob-
tained from the experimental work presented here.
at the Serveis de Recursos Cientifics i Tecnics (Univer-
sity of Rovira i Virgili, Tarragona). FAB+ mass spectra
were performed at the Servei dꢀEspectrometria de
Masses (University of Barcelona) using 3-nitrobenzylal-
cohol (NBA) as matrix.
Infrared spectra were obtained with a Nicolet 400-
FTIR instrument using KBr pellets. Routine 1H and
13C{1H} NMR spectra were obtained with a Gemini
200 MHz and a Bruker 250-DXR or a Mercury 400
MHz instruments, respectively. High-resolution 1H
NMR spectra and the two dimensional [{1H–1H} NO-
ESY, ROESY and COSY and {1H–13C}-heteronuclear
single quantum coherence (HSQC) and the heteronu-
clear multiple bond coherence (HMBC)] NMR experi-
ments were recorded with either a Varian VRX-500 or
with a Bruker Advance DMX 500 instruments at 20
ꢁC. Variable temperature H- and 31P{1H} NMR spec-
1
tra were carried out using a Bruker Advance DMX
500 and a Bruker 250-DXR instruments, respectively.
In all the NMR experiments the solvent was CDCl3
(99.8%) and SiMe4 was used as internal reference.
31P{1H} and 195Pt{1H} NMR spectra (at 20 ꢁC) were
obtained with a Bruker 250-DXR instruments in CDCl3
(99.9%) and using P(O)Me3 [d 31P = 141.1 ppm] and
H2[PtCl6] [d 195Pt = 0.0 ppm] as references, respectively.
4. Experimental
4.2. Preparation of the compounds
4.1. Materials and methods
4.2.1. Preparation of [Pt{[(g5-C5H3)–CH‚N–(C6H4-
2-SMe)]Fe(g5-C5H5)] Fe(g5-C5H5)}(PPh3)]Cl (6a)
Compound [Pt{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]-
Fe(g5-C5H5)}Cl] (5a) (61 mg, 1.08 · 10ꢀ4 mol) was dis-
solved in 10 ml of CH2Cl2, then the stoichiometric
amount amount of PPh3 was added. The reaction
Compounds [M{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]
Fe(g5-C5H5)}Cl] [with M = Pt (5a) or Pd (5b)], [Pt{[(g5-
C5H3)–CH‚N–(CH2)3–NMe2]Fe(g5-C5H5)}(PPh3)]
[BF4] (9b) and Tl[BF4] were prepared as described previ-
Table 1
5
˚
Selected bond lengths (A) and angles (ꢁ) for the cyclopalladated complexes of general formulae: [M{(C6H4)–CH‚N–(C6H4–2-SMe)]Fe(g -
C5H5)}Cl] {M = Pt (4a), Pd (4b)} and [M{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}Cl] {M = Pt (5a), Pd (5b)} (standard deviation
parameters are given in parenthesis)a
M = Pt
M = Pd
4a
5a
2.328(3)
4b
5b
2.3653(11)
M–S
2.349(2)
2.016(6)
1.988(6)
2.292(2)
81.8(2)
2.3863(13)
1.987(3)
2.008(3)
M–C(6)
M–N
M–Cl
1.985(10)
1.998(7)
2.302(4)
80.8(4)
1.978(5)
2.020(3)
2.3006(17)
81.94(10)
84.83(9)
2.2851(11)
81.38(16)
84.72(8)
C(6)–M–N
N–M–S
C(6)–M–Cl
Cl–M–S
a
85.93(15)
96.7(2)
95.69(9)
85.6(2)
96.3(4)
97.60(13)
96.46(10)
96.90(5)
95.52(15)
98.83(6)
Data from [24b,26,28].

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3192
mixture was stirred at room temperature (ca. 20 ꢁC) for
1 h and then filtered out. The filtrate was then concen-
trated to dryness on a rotary evaporator and the purple
solid obtained was then washed several times with small
portions of n-hexane. The purple solid was air-dried
and then dried in vacuum for 4 days (yield: 61 mg,
68.5%). Characterisation data: Anal. (%). Calc. for
C36H31NClFeSPPt (found): C, 52.28(52.6); H,
3.78(4.1); N, 1.69(1.8) and S, 3.88(4.11). MS (FAB+):
of CH2Cl2 and passed through a short (2.5 cm · 3.0 cm)
SiO2 column chromatography. Elution with
a
CH2Cl2:MeOH (100:4) produced the release of a deep-
purple band which was collected and concentrated to
dryness. The solid isolated (6b) was collected and dried
in vacuum for 3 days (yield: 50 mg, 72.8%). Characteri-
sation data: Anal. (%) Calc. for C36H31NClFeSPPd Æ 1/4
CH2Cl2 (found): C, 57.31(57.4); H, 4.11(4.2); N,
1.85(1.8) and S, 4.37(4.2). MS (FAB+): m/z = 703
[M ꢀ 1/4(CH2Cl2)–Cl]+. IR: 1544 cmꢀ1 [m(˜C‚N–)].
1H NMR data (500 MHz): d (in ppm) = 1.99 (s, 3H,
SMe), 3.77 (d, 1H, H3, J = 2), 4.24 (s, 5H, C5H5), 4.57
1
m/z = 792 {[M]–Cl}+. IR: 1533 cmꢀ1 [m(˜C‚N–)]. H
NMR data (500 MHz): at 300 K, d (in ppm) = 2.00
(br., 3H, SMe), 3.75 (s, 1H, H3), 4.20 (br., 5H, C5H5),
0
4.73 (s, 1H, H4), 5.09 (s, 1H, H5), 7.30 (t, 1H, H3 ,
(t, 1H, H4, J = 2), 5.07 (d, 1H, H5, J = 2), 5.12 (s,
0
0
0
J = 8), 7.34 (d, 1H, H3 , J = 8), 7.47 (t, 1H, H4 , J = 8),
7.50–7.70 (m, 15 H, aromatic protons of PPh3), 8.15
(d, 1H, Ha proton of one of the phenyl rings of the
PPh3, J = 8.0) and 9.61 (d, 1H, –CH‚N–,
4JP–H = 9.0); at 230 K (major component): d (in
ppm) = 2.13 (br., 3H, SMe), 3.72 (s, 1H, H3), 4.00 (br.,
5H, C5H5), 4.72 (s, 1H, H4), 5.02 (s, 1H, H5), 7.31 (t,
0.50H, CH2Cl2), 8.50 (d, 1H, H3 , J = 7.5), 7.30 (t, 1H,
0
H4 , J = 7.5), 7.55 (t, 1H, H5 , J = 7.5), 7.37 (d, 1H,
0
H6 , J = 7.5), 7.50–7.82 (m, 15H, aromatic protons of
4
PPh3) and 9.47 (s, 1H, –CH‚N–, JP–H = 8.5 Hz).
13C{1H} NMR (100.5 MHz): d (in ppm) = 24.8 (SMe),
71.7 (C5H5), 79.2 (d, C3, JP–C = 6.6 Hz), 73.0 (C4),
71.4 (C5), 91.5 0 (C1), 108.5 0 (d, C2, JP–C = 8.4), 1280.2
0
0
0
0
1H, H40 , J = 7.9), 7.36 (d, 1H, H3 , J = 07.9), 7.44 (t,
1H, H5 , J = 7.9), 7.50–7.70 (m, 15 H, H6 and 14 aro-
matic protons of PPh3), 8.04 (d, 1H, Ha of one of the
phenyl rings of the PPh3 group, J = 8) and 9.51 (d,
1H, –CH‚N–, 3JPt–H = 100, 4JP–H = 9); (minor compo-
nent): d (in ppm) = 1.82 (br., 3H, SMe), 3.72 (s, 1H, H3),
(C2 ), 1190.5 (C3 ), 128.4 (C4 ), 132.2 (C5 ), 133.6 (C6 ),
148.7 (C1 ), 171.5 (˜C‚N–) and four additional dou-
blets centered at 128.5, 130.5, 131.4 and 134.0 ppm
due to the four types of carbon-13 nuclei of the phenyl
rings of the PPh3. 31P{1H} NMR: d (in ppm) = 34.8.
4.39 (br., 5H, C5H5), 4.72 (s, 1H, H4)0, 5.08 (s, 1H, H5),
4.2.3. Preparation of [Pt{[(g5-C5H3)–CH‚N–(C6H4–2-
SMe)]Fe(g5-C5H5)]Fe(g5-C5H5)}(PPh3)][BF4] (7a)
To a solution containing 44 mg (5.3 · 10ꢀ5 mol) of
[Pt{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}Cl]
(5a) and 10 ml of acetone, Tl[BF4] (23 mg, 7.9 · 10ꢀ5
mol) was added. The reaction mixture was stirred at
ca. 20 ꢁC for 1 h and then filtered. The filtrate was
concentrated to dryness on a rotary evaporator and
then treated with the minimum amount of CH2Cl2.
The undissolved materials were removed by filtration
and the resulting purple solution was concentrated
to dryness on a rotary evaporator giving a deep pur-
ple solid (yield: 38 mg, 90.5%). Characterisation data:
Anal. (%) Calc. for C36H31NBF4FeSPPt Æ 1/2CH2Cl2
(found): C, 47.61(47.8); H, 3.50(3.80); N, 1.52(1.6)
and S, 3.48 (3.1). FAB+(MS): m/z = 792 {M–[BF4]ꢀ}.
0
7.29 (t, 1H, H4 , J = 8), 7.45 (t, 1H, H5 , J = 8), 7.50–7.70
0
(m, 15 H, H6 and 14 aromatic protons of PPh3), 8.11(Ha
of one of the phenyl rings of the PPh3 group, J = 8.5)
3
4
and 9.60 (d, 1H, –CH–N–, JPt–H = 100, JP–H = 9) in
0
this case the resonances due to the H3 and H4 were par-
tially overlapped and masked, respectively, by the sig-
nals due to the same protons of the major component.
13C{1H} NMR data (100.58 MHz): at 300 K, d (in
ppm) = 27.9 (SMe), 71.2 (C5), 72.0 (C5H5), 72.4 (C4),
75.8 (C3),0 80.1 [C1, JPt–C = 121.8], 92.7 (C2, JPt–C = 56),
0
0
1200.3 (C3 , JPt–C = 55.8), 128.4 (C2 ), 129.1 (C4 ), 129.9
0
(C6 ), 143.5 (C1 ), 172.6 (–CH‚N–) and four additional
doublets due to the four types of carbon-13 nuclei of the
PPh3 at 129.5, 132.2, 133.2 and 134.4. 31P{1H} NMR
data: at 300 K, d (in ppm) = 15.2 {1JPt–P = 3785}; at
230 K, d (in ppm) = 15.5 {1JPt–P = 3763} and 15.20
{1JPt–P = 3763}. 195Pt{1H} NMR data at 300 K, d (in
ppm) = ꢀ4449 {1JPt–P = 3785}.
1
IR (in cmꢀ1): 1533 [m(˜C‚N–)] and 1062 [BF4]ꢀ. H
NMR data (500 MHz): at 300 K, d (in ppm) = 2.0
(br., 3H, SMe), 3.75 (s, 1H, H3), 4.20 (br., 5H,
C5H5); 4.73 (s, 1H, H4), 5.09 (s,1H, H5), 7.30 (t,
0
0
0
4.2.2. Preparation of [Pd{[(g5-C5H3)–CH‚N–(C6H4–
2-SMe)]Fe(g5-C5H5)]Fe(g5-C5H5)}(PPh3)]Cl (6b)
To a solution containing (43 mg, 9.04 · 10ꢀ5 mol) of
[Pd{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)]
Fe(g5-C5H5)}Cl] (5b) and 20 ml of acetone, triphenyl-
phosphine (35 mg, 1.34 · 10ꢀ4 mol) was added. The re-
action mixture was refluxed for 2 h. After this period the
resulting deep purple solution was filtered out and the
filtrate was concentrated to dryness on a rotary evapora-
tor. The residue was dissolved in the minimum amount
1H, H2 , J = 8), 7.34 (d, 1H, H3 ), 7.47 (t, 1H, H4 ),
7.50–7.70 (m, 15 H, aromatic protons of PPh3), 8.15
(d, 1H, Ha of one of the phenyl rings of the PPh3
3
group, J = 7.5) and 9.61 (d, 1H, –CH‚N–, J = 100,
4JP–H = 9); at 230
K (major component): d (in
ppm) = 2.13 (br., 3H, SMe), 3.72 (s, 1H, H3), 4.00
(br., 5H, C5H5), 0 4.72 (s, 1H, H4), 5.02 (s, 1H, H5),
0
7.301 (t, 1H, H4 ), 7.36 (d,0 1H, H3 ), 7.44 (t, 1H,
H5 ), 7.50–7.70 (m, 15 H, H6 and 14 aromatic protons
of PPh3), 8.04 (d, 1H, Ha of one of the phenyl rings

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S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3193
0
0
of the PPh3 group, J = 7.5), 9.51 (d, 1H, –CH–N–,
4JP–H = 9); (minor component): d (in ppm) = 1.82
(br., 3H, SMe), 3.72 (s, 1H, H3), 4.39 (br., 5H,
C5H5), 4.72 (s, 1H, H4), 0 5.08 (s, 1H, H5), 7.29 (t,
H5, J = 2), 7.30 (t, 1H, H4 , J = 7.5); 7.37 (d, 1H, H6 ,
0
J = 7.5), 7.55 (t, 1H, H5 , J = 7.5); 7.50–7.802 (m, 15H,
3
aromatic protons of PPh3) 8.50 (d, 1H, H3 , J = 7.5),
3
and 9.47 (s, 1H, –CH‚N–, JP–H = 8.5). 13C{1H}
4
0
0
1H, H4 ), 7.45 (t, 1H, H5 ), 7.50–7.70 (m, 15 H, H6
NMR (100.5 MHz): d (in ppm) = 24.8(SMe), 71.4 (C5),
and 14 aromatic protons of PPh3), 8.11 (Ha of one
of the phenyl rings of the PPh3 group, J = 8.5), 9.60
71.7 (C5H5), 73.0 (C4), 79.2 (d, C3, JP–C = 6.6), 910.5
0
(C1), 108.05 (d, C2, JP–C = 8.4), 119.5 (C3 ), 128.2 (C2 ),
0
0
0
4
(d, 1H, –CH–N–, JP–H = 9), in this case the resonances
128.4 (C4 ), 132.2 (C5 ); 133.6 (C6 ), 148.7 (C1 ), 171.5
(˜C‚N–) and four additional doublets centered at
128.5, 130.5, 131.4 and 134.0 ppm due to the four types
of carbon-13 nuclei of the phenyl rings of the PPh3.
31P{1H} NMR: d (in ppm) = 34.9.
0
due to the H3and H4 were partially overlapped or
masked, respectivelly by the signals due to the same
protons of the major component. 13C{1H} NMR data
(100.58 MHz): at 300 K, d (in ppm) = 27.9 (SMe),
71.2 (C5), 72.0 (C5H5), 72.4 (C4), 75.8 (C3), 80.1 (C10,
JPt–C = 121.8), 92.7 (C2, JPt–C = 56), 120.3 (C3 ,
4.2.5. Preparation of [Pd{[(g5-C5H3)–CH‚N–(C6H5-
2SMe)]Fe(g5-C5H5)]Fe(g5-C5H5)}Cl(PPh3)] (8b)
A mixture containing 51 mg (1.07 · 10ꢀ4mol) of
[Pd{[(g5-C5H3)–CH‚N–(C6H5-2SMe)]Fe(g5-C5H5)]Fe
(g5-C5H5)}Cl] (5b), triphenylphosphine (42 mg,
1.6 · 10ꢀ4 mmol) and benzene (10 ml) was refluxed for
24 h. After this period the reaction mixture was allowed
to cool to room temperature and then filtered out. The
purple solution was concentrated to dryness on a rotary
evaporator. The residue was then dissolved in the mini-
mum amount of CH2Cl2 and passed through a short
SiO2 column chromatography (2.0 cm · 2.5 cm). Elution
with CH2Cl2 produced the release of a purple band which
was collected and thenconcentratedto drynesson a rotary
evaporator. The solid obtained was air-dried and then
dried in vacuum for 2 days (yield: 69 mg, 87%). Charac-
terisation data: Anal. (%) Calc. for C36H31NClFeSPdP
(found): C, 58.6 (58.3); H, 4.23(4.5); N, 1.90(1.8) and
S, 4.34(4.2). MS(MALDI-TOF+): m/z = 738 [M]+, 702
[M–Cl]+, 669 [M–Cl–CH3]+. IR (in cmꢀ1): 1544
0
0
0
JPt–C = 55.8), 128.4 (C2 ), 129.1 (C4 ), 129.9 (C6 ), 143.5
0
(C1 ), 172.6 (–CH‚N–) and four additional doublets
due to the four types of carbon-13 nuclei of the
PPh3 at 129.5, 132.2, 133.2 and 134.4. 31P{1H} NMR
data: at 300 K, d (in ppm) = 15.2(1JPt–P = 3785); at
230 K, d = 15.5(1JPt–P = 3763) and 15.20 (1JPt–P
=
3763). 195Pt{1H} NMR data at 300 K d (in ppm) =
ꢀ4449 (1JPt–P = 3763).
4.2.4. Preparation of [Pd{[(g5-C5H3)–CH‚N–(C6H4-
SMe)]Fe(g5-C5H5)]Fe(g5-C5H5)}(PPh3)][BF4] (7b)
This compound was prepared using either compound
5b or complex 6b as starting materials [methods (a) and
(b), respectively].
Method (a): In this case the synthesis was achieved
according to the procedure described above for 7a but
using 5.3 · 10ꢀ5 mol of [Pd{[(g5-C5H3)–CH‚N–
(C6H4-SMe)]Fe(g5-C5H5)]Fe(g5-C5H5)}Cl] (5b) and
the stoichiometric amounts of Tl[BF4] and PPh3 as start-
ing materials. The complex was recrystallised in CH2Cl2
(yield: 28 mg, 64%).
Method (b): Compound 6b (53 mg, 6.98 · 10ꢀ5 mol)
was dissolved in 20 ml of acetone, then the equimolar
amount of Tl[BF4] (20 mg, 6.98 · 10ꢀ5) was added.
The reaction mixture was stirred at room temperature
for 1 h and then the thallium(I) chloride formed was re-
moved by filtration and discarded. The filtrate was con-
centrated to dryness on a rotary evaporator. The deep
residue was dissolved in the minimum amount of
CH2Cl2 (ca. 5 ml) and the undissolved materials were re-
moved by filtration. The filtrate was concentrated to
dryness on a rotary evaporator and the solid formed
was dried in vacuum for 2 days (yield: 40 mg, 77%).
[m(˜C‚N–)]. 1H NMR data (500 MHz):
d (in
ppm) = 2.37 (s, 3H, SMe); 3.64 (s, 1H, H3), 3.94 (s,
5H, C5H5), 4.39 (s, 1H, H4), 4.50 (s, 1H, H5), 6.77 (t,
0
0
1H, H4 , J = 8), 6.90 (t, 1H, H5 , J = 8), 7.22 (d, 1H,
0
0
H3 , J = 8), 7.27 (d, 1H, H6 , J = 8), 8.54 (d, 1H, –
CH‚N–, JP–H = 9) and 7.55–7.80 (m, 15H, aromatic
protons of the PPh3 ligand). 13C{1H} NMR data (in
ppm): d = 18.12(SMe), 68.7 (C3), 70.8 (C5H05), 72.2
(C4); 79.2 (C4), 92.6 (C1), 106.6 (C2), 114.9 (C3 ), 1220.2
0
0
0
0
(C4 ), 127.7 (C5 ), 131.4 (C6 ), 149.5 (C1 ), 147.4 (C2 ),
163.6 (˜C‚N–) and three additional doublets centered
at: 128.8, 129.2, 131.0 and 134.7 due to the four types
of carbon nuclei of the PPh3 ligand. 31P{1H} NMR data
(in ppm): d = 38.1.
4.2.4.1. Characterisation data. Anal. (%) Calc. for
C36H31NBF4FeSPPd Æ CH2Cl2 (found): C, 50.81(50.4),
H, 3.80(3.8), N, 1.60(1.60) and S, 3.66(3.3). MS(FAB+):
m/z = 703 {M–[BF4]ꢀ}. IR (in cmꢀ1): 1544 [m(˜C‚N–)];
1096 [BF4]ꢀ. 1H NMR data (500 MHz): d (in
ppm) = 1.99 (s, 3H, SMe), 3.77 (d, 1H, H3, J = 2), 4.24
(s, 5H, C5H5), 4.57 (t, 1H, H4, 3J = 2), 5.07 (d, 1H,
4.3. Crystallography
A prismatic crystal of 7b or 9b (sizes in Table 2) was
selected and mounted on a MAR345 diffractometer with
a image plate detector. Unit cell parameters were deter-
mined from automatic centering of 9390 (for 7b) or 4616
(for 9b) reflections in the range 3ꢁ<H<31ꢁ, and refined

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3194
Table 2
Crystal data and details of the refinement of the crystal structures of [Pd{[(g5-C5H3)–CH‚N–(C6H4–2-SMe)]Fe(g5-C5H5)}(PPh3)][BF4] Æ CH2Cl2
(7b) and [Pd{[(g5-C5H3)–CH‚N–(CH2–CH2–CH2–NMe2)]Fe(g5-C5H5)}(PPh3)][BF4] Æ CHCl3 (9b) (standard deviation parameters are given in
parenthesis)
7b
9b
Empirical formula
Formula weight
Crystal size (mm · mm · mm)
T (K)
C
838.18
37H32BCl2F4FeNPPdS
C35H36BCl3F4FeN2PPdS
871.04
0.1 · 0.1 · 0.2
293(2)
0.71069
0.1 · 0.1 · 0.2
293(2)
0.71069
˚
k (A)
Crystal system
Triclinic
ꢀ
Triclinic
ꢀ
Space group
˚
P1
P1
10.3190(10)
a (A)
˚
10.6170(10)
12.9620(10)
13.9270(10)
82.845(10)
79.589(10)
74.286(10)
1808.8(3)
b (A)
10.6520(10)
17.3220(10)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
84.40
87.08
74.14
1822.2(3)
V (Mg mꢀ3
)
Absorption coefficient (mmꢀ1
F(000)
)
1.122
844
1.204
878
H range for data collection (ꢁ)
Number of collected reflections
Number of unique reflections (Rint
Number of data
2.02–31.61
12681
2.36–31.59
3003
)
8353 (0.0319)
8353
442
3003 (0.0267)
3003
Number of parameters
Goodness-of-fit on F2
434
1.075
1.048
R indices [I>2r(I)]
R indices (all data)
Largest difference in peak and hole (e Aꢀ3
R1 = 0.0413, wR2 = 0.1202
R1 = 0.0604, wR2 = 0.1296
0.809 and ꢀ0.843
R1 = 0.0331, wR2 = 0.0953
R1 = 0.0401, wR2 = 0.0987
0.251 and ꢀ0.360
)
by full-matrix least-squares method. Intensities were col-
lected with graphite monochromatized Mo-Ka radia-
tion. For 7b, the number of measured reflections was
12681 (in the range 2.02ꢁ 6 H 6 31.61ꢁ) and for 9b,
3003 reflections were measured in the range
2.36ꢁ 6 H 6 31.59ꢁ. The number of reflections assumed
as observed applying the condition I>2r(I) was 8353
(for 7b) and 2626 (for 9b). Lorentz-polarisation correc-
tions were made, but absorption corrections were not.
The structures were solved by Direct methods, using
SHELXS computer program [37] and refined by full-ma-
trix least-squares method with the SHELX-97 computer
program [38] using 8353 reflections (very negative reflec-
Acknowledgements
This work was performed with the financial support
´
of the Ministerio de Ciencia y Tecnologıa of Spain,
the Generalitat de Catalunya (Grant Nos. BQU2003-
00906 and SRG2001-00054, respectively) and FEDER
funds. S.P. is grafetul to the Generalitat de Catalunya
for a pre-doctoral fellowship.
Appendix A. Supplementary material
Crystallographic data for the structural analyses of
7b and 9b have been deposited at the Cambridge
Crystallographic Data Centre, CCDC Nos. 240806
and 240807, respectively. Copies of this information
can be obtained from The Director, CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (fax: +44-1233-
336033; e-mail: deposit@ccdc.ac.uk or www: http://
www.ccdc.cam.ac.uk). Supplementary data associated
with this article can be found, in the online version
at doi:10.1016/j.jorganchem.2004.07.007.
tions were not assumed). The function minimised was
P
w = iFo|2 ꢀ |Fc|2|, where w = [r2(I) + (0.0909P)2]ꢀ1
(for 7b) and w = [r2(I) + (0.0688P)2]2 + (0.3904P)]ꢀ1
and P = (|Fo|2 + 2|Fc|2)/3; f, f0 and f00 were obtained from
the literature [39]. For 7b, the fluorine atoms of the
[BF4]ꢀ anion were located in disordered positions. An
ocupancy factor equal to 0.5 was assumed according
to the height of the difference synthesis. For the two
structures, all hydrogen atoms were computed and re-
fined using a riding model with an isotropic temperature
factor equal to 1.2 times the equivalent temperature fac-
tor of the atom linked to it. The final R (on F) factor was
0.041, wR (on Fo) = 0.0120. Further details concerning
the resolution and refinement of the crystal structures
are presented in Table 2.
References
[1] (a) J. Dupont, M. Pfeffer, J. Spencer, Eur. J. Inorg. Chem. (2001)
1917;

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3195
(b) R.G. Newkome, G.E. Puckett, V.K. Gupta, G.E. Kiefer,
Chem. Rev. 86 (1986) 45;
(f) J.A.G. Williams, A. Beeby, E.S. Davies, J.A. Weinstein, C.
Wilson, Inorg. Chem. 42 (2003) 8609.
(c) V.V. Dunina, O.A. Zalevskaya, V.M. Potatov, Russ. Chem.
Rev. 57 (1988) 250 (Engl. Transl.);
[13] (a) For a general overview of the applications of cyclopalladated
and cycloplatinated complexes in organic or organometallic
syntheses see for instance: A.D. Ryabov, Synthesis (1985) 233;
(b) M. Pfeffer, Rec. Trav. Pays-Bas 109 (1990) 567;
(d) A.D. Ryabov, Chem. Rev. 90 (1990) 403;
(e) I. Omae, Coord. Chem. Rev. 83 (1988) 137.
(c) J. Spencer, M. Pfeffer, Adv. Met. Org. Chem. 6 (1986) 103.
[14] N. Gul, J.H. Nelson, A.C. Willis, A.D. Ross, Organometallics 21
¨
[2] (a) P.W. Jolly, G. Wilke, W.A. Kermann, B. Cornils (Eds.),
Applied Homogeneous Catalysis with Organometallic Com-
pounds, VCH, Weinheim, 1996;
(2002) 2041.
[15] (a) M. Pfeffer, J.P. Sutter, A. De Cian, J. Fischer, Organometallics
12 (1993) 1167;
(b) I. Omae, Applications of Organometallic Compounds, Wiley,
Chichester, 1998 (Chapter 20).
(b) M. Pfeffer, M.A. Rotteveel, J.P. Sutter, A. de Cian, J. Fischer,
J. Organomet. Chem. 371 (1989) C21.
[16] G. Zhao, Q.G. Wang, T.C.W. Mak, J. Organomet. Chem. 574
(1999) 311.
[3] A.J. Klaus, in: A.E. Peters, H.S. Freeman (Eds.), Modern
Colorants: Synthesis and Structure, vol. 3, Blackie Academic
Press, London, 1995.
[4] (a) B.S. Wild, Coord. Chem. Rev. 166 (1997) 291;
(b) J. Bravo, C. Cativiela, J.E. Chaves, R. Navarro, E.P.
Urriolabeitia, Inorg. Chem. 42 (2003) 1006.
´ ´
[17] (a) M. Benito, C. Lopez, X. Morvan, X. Solans, M. Font-Bardıa,
J. Chem. Soc, Dalton Trans. (2000) 4470;
´ ´
(b) M. Benito, C. Lopez, X. Solans, M. Font-Bardıa, Tetrahe-
dron: Asymmetry 9 (1998) 4219;
[5] K.E. Torraca, S.I. Kuwabe, S.L. Buchwald, J. Am. Chem. Soc.
122 (2000) 12907.
´
(c) R. Bosque, M. Benito, C. Lopez, New J. Chem. 25 (2001) 827.
[6] J.L. Serrano (Ed.), Metallomesogens, Synthesis, Properties and
Applications, VCH, Weinheim, 1996.
[18] (a) For recent advances in the use of cycloplatinated and
cyclopalladated complexes in organic and organometallic synthe-
sis, see for instance: J.J. Johnson, D. Sames, J. Am. Chem. Soc.
122 (2000) 6321;
[7] D.E. Bergbreiter, P.L. Osburn, Y.S. Liu, J. Am. Chem. Soc. 121
(1999) 9531.
[8] M. Talarico, G. Barberio, D. Pucci, M. Ghedini, A. Golemme,
Adv. Mater. 15 (2003) 1374.
´ ´
(b) S. Perez, C. Lopez, A. Caubet, A. Pawelczyk, X. Solans, M.
´
Font-Bardıa, Organometallics 22 (2003) 2937.
[19] R.G. Pearson, J. Am. Chem. Soc. 85 (1963) 3533.
[9] (a) L. Diez, P. Espinet, J.A. Miguel, J. Chem. Soc., Dalton Trans.
(2001) 1189;
´
[20] (a) M. Crespo, J. Granell, X. Solans, M. Font-Bardıa, J.
Organomet. Chem. 681 (2003) 143;
(b) G. Ciparrone, A. Mazzulla, I. Aiello, M. Ghedini, Mol. Cryst.
Liquid Cryst. 320 (1998) 165.
´
(b) C. Anderson, M. Crespo, M. Font-Bardıa, A. Klein, X.
Solans, J. Organomet. Chem. 601 (2000) 22;
[10] (a) For recent contributions centered on the use of
cycloplatina- and/or cyclopalladated complexes in homoge-
neous catalysis, see for instance: R.B. Bedford, S.L.
Hazelwood, M.E. Limmert, D.A. Albisson, S.M. Draper,
P.N. Scully, S.J. Coles, M.B. Hursthouse, Chem. Eur. J. 9
(2003) 3216;
´ ´
(c) O. Lopez, M. Crespo, M. Font-Bardıa, X. Solans, Organo-
metallics 16 (1997) 1233.
[21] (a) A. Ferna´ndez, P. Uria, J.J. Ferna´ndez, M. Lo´pez-Torres, A.
´ ´
Suarez, D. Vazquez-Garcıa, M.T. Pereira, J.M. Vila, J. Organo-
met. Chem. 620 (2001) 8;
(b) R.B. Bedford, C.S.J. Cazin, S.J. Coles, T. Gelbrich,
P.N. Horton, M.B. Hursthouese, M.E. Light, Organometal-
lics 22 (2003) 987;
´
´
´
´
(b) A. Fernandez, J.J. Fernandez, M. Lopez-Torres, A. Suarez,
J.M. Ortigueira, J.M. Vila, H. Adams, J. Organomet. Chem.
621 (2000) 85.
(c) F. Yang, Y. Zhang, R. Zheng, J. Tang, M. He, J.
Organomet. Chem. 651 (2002) 146;
[22] C. Cativiela, L.R. Falvello, J.C. Gines, R. Navarro, E.P.
Urriolabeitia, New J. Chem. 25 (2001) 344.
´ ´ ´
[23] (a) S. Perez, C. Lopez, A. Caubet, X. Solans, M. Font-Bardıa,
(d) C. Rocaboy, J.A. Gladysz, Org. Lett. 4 (2002) 1993;
(e) A.D. Ryabov, E.Y. Bezsoudnova, J. Organomet. Chem.
622 (2001) 38;
New J. Chem. 27 (2003) 975;
´ ´
(b) C. Lopez, A. Caubet, S. Perez, X. Solans, M. Font-Bardıa, J.
´
(f) A.W. Kleij, R.J.M.K. Gebbink, P.A.J. van den Nie-
uwenhuijzen, H. Kooijman, M. Lutz, A.L. Spek, G. van
Koten, Organometallics 20 (2001) 634;
Organomet. Chem. 651 (2002) 105.
´ ´
[24] (a) A. Caubet, C. Lopez, X. Solans, M. Font-Bardıa, J. Organ-
omet. Chem. 577 (1999) 735;
(g) J.S. Fossey, C.J. Christopher, Organometallics 23 (2004)
367;
´ ´ ´
(b) C. Lopez, S. Perez, X. Solans, M. Font-Bardıa, J. Organomet.
Chem. 650 (2002) 258;
´ ´
(c) C. Lopez, A. Pawelczyk, X. Solans, M. Font-Bardıa, Inorg.
(h) J. Bravo, C. Cativiela, R. Navarro, E.P. Urriolabeitia,
J. Organomet. Chem. 650 (2002) 157.
Chem. Commun. 6 (2003) 451.
´
[25] (a) X. Riera, C. Lopez, A. Caubet, V. Moreno, X. Solans, M.
[11] E.G. Rodrigues, L.S. Silva, D.M. Fausto, M.S. Hayashi, S.
Dreher, E. Santos, J.B. Pesquero, L.R. Travessos, A.C.F. Caires,
Int. J. Cancer 107 (2003) 498.
´
Font-Bardıa, Eur. J. Inorg. Chem. (2001) 2135;
´
(b) X. Riera, A. Caubet, C. Lopez, V. Moreno, X. Solans, M.
[12] (a) For recent advances in the photoptical properties of cyclopla-
tinated and cyclopalladated complexes, see for instance: C.M.
Che, W.F. Fu, S.W. Lai, Y.J. Hou, Y.L. Liu, Chem. Commun.
(2003) 118;
´
Font-Bardıa, Organometallics 19 (2000) 1384;
(c) X. Riera, A. Caubet, C. Lo´pez, V. Moreno, E. Freisinger,
M. Willermann, B. Lippert, J. Organomet. Chem. 629 (2001)
97.
´ ´
[26] A. Caubet, C. Lopez, X. Solans, M. Font-Bardıa, J. Organomet.
(b) C.H. Tao, K.M.C. Wong, N. Zhu, V.W. Yam, New J. Chem.
23 (2003) 150;
Chem. 669 (2003) 164.
´ ´
[27] C. Lopez, A. Caubet, R. Bosque, X. Solans, M. Font-Bardıa, J.
´ ´ ´
(c) S. Fernandez, J. Fornies, B. Gil, J. Gomez, E. Lalinde, J.
Chem. Soc., Dalton Trans. (2003) 822;
Organomet. Chem. 645 (2002) 146.
´ ´
[28] S. Perez, C. Lopez, A. Caubet, X. Solans, M. Font-Bardıa, E.
(d) I. Aiello, U. Caruso, M. Panunzi, A. Quatela, A. Roviello, F.
Sarcinelli, Polymer 44 (2003) 7635;
´
Molins, A. Roig, Organometallics 23 (2004) 224.
[29] K. Nakamoto, IR and Raman Spectra of Inorganic Coordination
Compounds, fifth ed., Wiley, New York, 1997.
(e) I. Aiello, D. Dattilo, G. Mauro, A. Bruno, R. Termine, G.
Atilio, Adv. Mater. 14 (2002) 1233;

´
S. Perez et al. / Journal of Organometallic Chemistry 689 (2004) 3184–3196
3196
´ ´
(c) M. Benito, C. Lopez, X. Solans, M. Font-Bardıa, Tetrahedron
Asymm. 9 (1998) 429.
[30] G.B. Deacon, J.H.S. Green, Spectrochim. Acta A 24 (1968) 845.
[31] P.S. Pregosin, Coord. Chem. Rev. 44 (1982) 247.
[32] (a) J. Vicente, A. Arcas, D. Bautista, P.G. Jones, Organometallics
16 (1997) 2127;
[35] C. Kowala, J.M. Swan, Aust. J. Chem. 19 (1996) 547.
[36] D.D. Perrin, W.L. Armarego, Purification of Laboratory Chem-
icals, third ed., Pergamon Press, London, 1998.
[37] G.M. Sheldrick, SHELXS: A Computer Program for Determina-
tion of Crystal Structure, University of Go¨ttingen, Go¨ttingen,
Germany, 1997.
(b) J. Vicente, J.A. Abad, A.D. Frankland, M.C. Ramirez de
Arellano, Chem. Eur. J. 5 (1999) 3066;
´
(c) J. Vicente, J.A. Abad, E. Martınez-Viviente, P.G. Jones,
Organometallics 21 (2002) 4454.
[33] T.H. Allen, O. Kennard, Chem. Des. Automat. News 8 (1993) 128.
[38] G.M. Sheldrick, SHELX-97: A Computer Program for Determi-
nation of Crystal Structure, University of Go¨ttingen, Go¨ttingen,
Germany, 1979.
´
[34] (a) C. Lopez, J. Sales, X. Solans, R. Zquiak, J. Chem. Soc.,
Dalton Trans. (1992) 2321;
´ ´
(b) R. Bosque, C. Lopez, J. Sales, X. Solans, M. Font-Bardıa, J.
Chem. Soc., Dalton Trans. (1994) 483;
[39] International Tables of X-Ray Crystallography, vol. IV, Kynoch
Press, 1974, pp. 99–100 and 149.